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1
Baxter, John S. "Transition metal mediated annulation reactions." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324243.
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2
Heshmati, Parissa. "Novel annulation reactions using cobalt stabilised carbonium ions." Thesis, Kingston University, 1994. http://eprints.kingston.ac.uk/20573/.
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This programme of work was aimed at the synthesis of a range of linear hydrocarbon molecules bearing functionality at each end. It was envisaged that by the application of an intramolecular Nicholas reaction the linear chain would cyclise to afford an [alpha],[beta] disubstituted cycloalkanone. The Nicholas reaction is based on the propargyl carbonium ions, stabilised with binuclear cobalt species, which are subject to nucleophilic attack at the propargyl position. This reaction has previously been exploited in syntheses in an intermolecular fashion, however, few approaches involving an intramolecular reaction have appeared in the literature. Thus, in the present study, investigation of the latter was undertaken. In this novel approach a series of 5,6 or 7 membered carbocyclic compounds were synthesised from precursor molecules containing 8,9,10 or 11 carbon chains. During this exercise one or two asymmetric centres were also created in a series of reactions that are the equivalent of a 1,4-addition of ethyne to an enone. All the synthetic steps were thoroughly investigated and optimised. It was also demonstrated that for unsymmetrical linear ketones, the kinetic enolates seem to predominate irrespective of the reaction conditions employed. This was in contrast to enolate formation in unsymmetrically substituted cyclic ketones, where selectivity between the kinetic and thermodynamic enolates has been observed by appropriate choice of base. Infra-red, [sup]1H N.M.R., [sup]13C N.M.R. and Mass spectroscopy analyses were performed on all the compounds synthesised. However cobalt complexed compounds showed some paramagnetism, possibly due to the presence of some paramagnetic impurities or by-products. This led to difficulties in interpretation of spectra as a result of line broadening. Future work might usefully investigate the use of these methodologies in the synthesis of fused carbocycles, heterocycles and highly functionalised fused ring systems, generated from a tandem intramolecular reaction involving a Nicholas reaction followed bya Pauson-Khand reaction.
3
Sabin, Verity Margaret. "Synthetic studies on two silicon assisted annulation reactions." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272796.
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4
Liu, Yang. "Studies on Palladium-Catalyzed [3+2]-Annulation/Domino Reactions." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS214.
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Ce travail de thèse est consacré à l'étude des réactions d'annélation [3+2] domino catalysées au palladium. Tout d'abord, une nouvelle séquence domino a été développée, qui implique la réaction entre les dérivés cycliques α,β-insaturés-γ-oxy-carbonylés et les acétamides stabilisés par résonance. Les pyrrolidine-2-ones bicycliques obtenues ont été générées par une allylation intermoléculaire catalysée au Pd, suivie d'une réaction d’aza-Michael intramoléculaire. Une version asymétrique a également été réalisée, obtenant jusqu'à 60% d’excès énantiomérique. Ensuite, une nouvelle séquence domino triple catalysée au Pd [allylation / aza-Michael / keto α-arylation] (ALAMAR) a également été réalisée, ce qui permet la formation sélective de systèmes tricycliques fusionnés en un seul pot. Enfin, deux transformations domino sélectives et complémentaires ont été réalisées, permettant d'effectuer au choix des annulations de type C−C/O−C ou C−C/C−C [3+2]. Ces transformations se produisent par le biais d'une séquence de [C-allylation intermoléculaire / O- ou C-1,4-addition conjuguée intramoléculaire]This thesis work is consecrated to the study of palladium-catalyzed [3+2]-annulation and domino reactions. First, a new domino sequence was developed, which involves the reaction between cyclic α,β-unsaturated-γ-oxy-carbonyl derivatives and resonance-stabilized acetamides. The resulting bicyclic pyrrolidin-2-ones were generated through an intermolecular Pd-catalyzed allylation followed by an intramolecular aza-Michael reaction sequence. An asymmetric version was also achieved, obtaining up to 60% ee. A new Pd-catalyzed [allylation / aza-Michael / keto α-arylation] (ALAMAR) triple domino sequence was also accomplished, which allows the selective one-pot formation of fused tricyclic systems. Lastly, two selective and complementary domino transformations have been achieved, which allow to perform C−C/O−C or C−C/C−C [3+2]-annulations at will. These transformations occur through an intermolecular Pd-catalyzed C-allylation / intramolecular O- or C-1,4-addition sequence, respectively
5
Flanagan, Stuart Robert. "New aromatic annulation reactions and their application in total synthesis." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402059.
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6
Chogii, Isaac, and Isaac Chogii. "New Anionic Annulation Reactions and Anion Accelerated Amino-Cope Rearrangement." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/621558.
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New Anionic Annulation Reactions and Anion Accelerated Amino-Cope Rearrangement. This dissertation compiles asymmetric anionic reactions of chiral Ellman sulfinyl imines and dienolates to access diverse nitrogen-containing compounds. Chiral sulfinimines and dienolates derived from 𝛾-bromocrotonates reacted diastereoselectively forming 3-pyrrolines and 𝑐𝑖𝑠-vinyl aziridines via a formal [3+2]-annulation and vinylogous 𝑎𝑧𝑎-Darzens reactions respectively. Concise asymmetric syntheses of three natural products have been achieved demonstrating the power of the [3+2]-methodology. Reaction of conjugated sulfinimines with enolates derived from non-halogen containing crotonates, were found to undergo a tandem diastereoselective α,α-addition, and anionic [3,3]-rearrangement affording vinylogous amide products. Synthesis of aromatic imines via 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) initiated oxidative aromatization highlights the synthetic value of the accelerated anion amino-Cope rearrangement.
7
Emrullahoglu, Mustafa. "Novel Annulation Reactions For The Synthesis Of Substituted Pyrroles Darzens Reaction Of Acyl Phosphonates With &." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610338/index.pdf.
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In the first part of this thesis, it is aimed to develope methods for the synthesis of trisubstituted
pyrrrole derivatives. 2-Aminopyrrroles, alkoxy and sulfonyl substittitued
pyrrole derivatives as well as pirolinones show interesting biological activities and
are precursor of well know drugs. Although there is a number of methods for the
synthesis of pyrroles, the synthesis of 2-aminopyrroles is limited to few works and is
not widely known. Therefore, it is still an important goal in organic chemistry to
improve methods for the synthesis of multifunctionalized pyrrole derivatives and
pyrrolinones.
Alkylation of β
-dicarbonyl compounds with bromoacetonitrile furnishes &
#945
- cyanomethyl-&
#946
-dicarbonyl compounds. The condensation reaction of &
#945
- v cyanomethyl-&
#946
-dicarbonyl compounds with amines catalyzed by p-TsOH affords the corresponding enamines and further base catalyzed cyclization furnishes 2- aminopyrroles in high yields, moreover, zinc perchlorate-catalyzed addition of amines, alcohols and thiols to the nitrile carbon of &
#945
-cyanomethyl-&
#946
-ketoesters followed by annulation gives the 5-alkoxy and 5-alkylsulfanylpyrrole-3-carboxylates in high yields. In the second part of the thesis, reactions of a broad range of acyl phosphonates with &
#945
-bromo acetophenones at room temperature in the presence of different bases were described to afford two diastereomeric epoxy phosphonates in good yields and high diastereoselectivities. The diastereoselectivity of this reaction is easily controlled by changing the base. Accordingly, changing the base from Cs2CO3 to DBU changes the diatereomeric ratio (trans/cis) from 5/3 to 9/1. Furthermore, the treatment of trans isomer with DBU shows a complete conversion to the corresponding cis isomer. Additionally, these highly functionalized epoxyphosphonates are shown to be useful intermediates to give several reactions
8
Marais, Pierre Christiaan. "New annulation methods : total synthesis of the diterpenoid (+--)-ambliol B." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30639.
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The preparation of bicyclic systems containing an allylic, angular hydroxyl group (general structure 20 and compound 87b) is described. These materials have been prepared via a new annulation sequence involving (a) the alkylation of cyclic ketones with the bifunctional conjunctive reagents 129, 21 and 60, (b) the conversion of the alkylation products into keto vinyl iodides, and (c) cyclization of the keto vinyl iodides via low temperature metal halogen exchange with n-butyllithium.
The cyclization process described in (c) has been employed in the first total synthesis of the diterpenoid (±)-ambliol B (94). Thus, 3,4-dimethyl-2-cyclohexen-l-one (96) was converted, in three steps, into the unstable enone 125. Reaction of this compound with the novel vinylgermane cuprate 110, followed by reaction of the resultant product with iodine, gave the cyclization precursor 106. Cyclization of 106 gave a single, trans-fused product (128) in high yield. The exocyclic methylene function of 128 was cyclopropanated and the vinyl substituent of the resultant cyclopropane was hydroborated to give the cyclopropane diol 149. Hydrogenolysis of the cyclopropane ring of compound 149 provided the required gem-dimethyl moiety. The resultant product was converted into (±)-ambliol B (94) via a four step sequence of reactions involving (a) oxidation of the primary alcohol function, (b) addition of 3-furyllithium to the so-formed unstable aldehyde, (c) acetylation of the secondary alcohol prepared in (b), and (d) reductive removal of the acetoxy function.
A new annulation sequence which utilizes the vinylgermane cuprate 110 as a synthetic equivalent of the 1-butene a²,d⁴-synthon 153 is described. Thus, cyclic enones of the general structure 154 were treated with 110 to provide the keto vinylgermane intermediates 155. The latter materials were transformed into the corresponding keto vinyl iodides 156. Treatment of 156 with a palladium(0) catalyst and a base resulted in cyclization to provide the annulation products 157 or, when R₁ = H, the α,β-unsaturated ketones 185.
[ Formulas omitted ]Science, Faculty of
Chemistry, Department of
Graduate
9
Davie, Christopher P. "[4 + 1] annulation reactions of (trialkylsilyl)ketenes : synthesis of substituted indanones and cyclopentenones." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33648.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.Vita.
Includes bibliographical references.
(Trialkylsilyl)vinylketenes ("(TAS)vinylketenes") and (trialkylsilyl)arylketenes ("(TAS)- arylketenes") function as versatile four-carbon building blocks for the synthesis of carbocyclic and heterocyclic compounds. A new [4 + 1] annulation strategy for the synthesis of substituted 2-indanones, based on the reaction of TAS-arylketenes with trimethylsilyl diazomethane, has been developed. In addition, a new class of carbenoid reagents for our previously reported [4 + 1] cyclopentenone annulation has been identified. Studies have shown that the reaction of a- benzotriazolyl organolithium compounds (prepared via metallation of readily available N- substituted benzotriazole derivatives) with (TAS)vinylketenes generates dienolate intermediates which cyclize to form cyclopentenones. Most cases of the annulation proceed with a high level of diastereoselectivity, and deliver highly substituted and functionalized 2-silylcyclopentenones in good yield. Furthermore, the vinylsilane moiety incorporated in the [4 + 1] annulation products provides a useful handle for further synthetic transformations. Preliminary studies focused on elaboration of the cyclopentenone products have laid the groundwork for future applications of this [4 + 1] annulation methodology.
by Christopher P. Davie.
Ph.D.
10
Ashida, Shinji. "Development of Nickel-Catalyzed Annulation Reactions Using Cyclobutanones as a Four-Carbon Unit." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/61312.
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Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第14053号
工博第2965号
新制||工||1440(附属図書館)
26332
UT51-2008-F445
京都大学大学院工学研究科合成・生物化学専攻
(主査)教授 村上 正浩, 教授 吉田 潤一, 教授 杉野目 道紀
学位規則第4条第1項該当
11
Hoffman, William Christopher. "Synthesis of fused carbocycles from benzoic acids via radical and anionic annulation procedures /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487331541711284.
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12
Prasad, Chaturvedula V. "Annulation and cycloaromatization reactions of 3-aryl (alkyl) thio-1-trimethylsiloxy-1-methoxy-1,3-butadienes." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75442.
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The title compounds were synthesized from methyl 3-aryl(alkyl)thio crotonic acids by deprotonation followed by silylation. The reactions of dienes with a number of carbonyl electrophiles under Lewis-acid catalysed conditions were investigated. The dienes exclusively give $ gamma$-alkylated products. The thio substituent enhances the $ gamma$-selectivity.The reactions of dienes with a number of 1,3-dicarbonyl equivalents have been studied and a cycloaromatization reaction has been developed for the regiocontrolled synthesis of aryl sulfides in a 3C + 3C combination. The role of dienes in Diels-Alder reactions has also been investigated.
A new 4C + 2C annulation reaction has been developed based on the propensity of dienes to undergo Michael reaction with $ alpha$,$ beta$-unsaturated ketones under Lewis-acid catalysed conditions. These Michael adducts in turn were cyclized either with potassium tert-butoxide or with lithium thiophenoxide. Further, the tandem Michael-Claisen annulation reaction can be controlled to give either cis- or trans-fused 9-methyldecalin system with three carbonyl groups which are differently masked. The chemoselective transformations of the carbonyl groups were also described.
13
Mo, Jiayu. "Iron-Catalyzed C–H/N–H Activations for Annulation of Allenes, Alkynes, and Bicyclopropylidenes." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://hdl.handle.net/21.11130/00-1735-0000-0005-14F0-5.
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14
Ebe, Yusuke. "Iridium-Catalyzed Carbon-Carbon Bond Formation Reactions via C-H Bond Activation." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225417.
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15
Li, Sun Verfasser], Dieter [Akademischer Betreuer] [Enders, and Markus [Akademischer Betreuer] Albrecht. "N-heterocyclic carbene catalyzed asymmetric cycloaddition/annulation reactions of enals and α-chloroaldehydes / Sun Li ; Dieter Enders, Markus Albrecht." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1170780156/34.
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16
Liu, Qiang [Verfasser], Dieter [Akademischer Betreuer] Enders, and Markus [Akademischer Betreuer] Albrecht. "N-Heterocyclic carbene catalyzed asymmetric cycloaddition/annulation reactions via homoenolates and azolium dienolates / Qiang Liu ; Dieter Enders, Markus Albrecht." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1180734548/34.
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17
Li, Sun [Verfasser], Dieter [Akademischer Betreuer] Enders, and Markus [Akademischer Betreuer] Albrecht. "N-heterocyclic carbene catalyzed asymmetric cycloaddition/annulation reactions of enals and α-chloroaldehydes / Sun Li ; Dieter Enders, Markus Albrecht." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1170780156/34.
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18
Igdir, A. Cigdem. "Reinvestigation Of The Synthetic And Mechanistic Aspects Of Manganese(iii) Acetate Mediated Reactions Synthesis Of 1,2,4-trisubstituted Pyrroles Via Amination / Annulation Reactions Of Chloroenones With Chiral Amine Compounds." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607643/index.pdf.
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The first part of the thesis presents the reinvestigation of the synthetic and mechanistic aspects of manganese (III) acetate mediated reactions. The main concern about this subject was to perform a ¢- acetoxylation reactions of enones and saturated systems in shorter reactions times and higher yields than the ones known in literature reproducibly. Although successful a ¢
-acetoxylation of a great variety of substrates have been reported so far, there are some problems associated with the use of Mn(OAc)3. Considering that there are not many simple methods for the direct acetoxylation of enones, optimization of Mn(OAc)3 mediated a ¢
-acetoxylation of enones and reaching its maximum potential has a great importance from a synthetic and economical point of view. In the second part of the thesis, 1,2,4-trisubstituted pyrrole derivatives were the target molecules to be synthesized. Although there are quite a number of methods available for the synthesis of pyrroles, most of them involve multistep synthetic operations which lower the overall yield. There are limited reports on the preparation of the enantiomers of pyrrole derivatives having 1-N directly linked to the stereogenic center. Thus, developing a new synthetic method for the efficient preparation of polysubstituted pyrroles without racemization still remains an attractive goal.
19
Aybey, Asuman. "Synthesis Of Chiral Lactones Via The Baeyer Villiger Oxidation Of Cyclic Aromatic Acetoxy Ketones Novel Annulation Reactions Of 2-propynyl-1,3-dicarbonyl Compounds To Form Pyrroles Addition Of Acyl Phosphonates To Diethyl Cyanophosphonate (depc)." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12610293/index.pdf.
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Chiral Baeyer-Villiger (BV) oxidation of cyclic ketones allows rapid access to asymmetric lactones as valuable intermediates in organic chemistry and frequently encountered precursors in enantioselective synthesis. In the first part, BV oxidation of functionalized ketones, especially cyclic 
-hydroxy and acetoxy ketones is described which could be a straightforward route to the &
#61537
-hydroxy lactones and &
#61537
-hydroxyalkanoic acid derivatives. The &
#61537
-acetoxylation of indanone, tetralone and chromanone derivatives by using Mn(OAc)3 followed by the enzyme catalyzed kinetic resolution of acetoxy ketones gives both of the enantiomers of &
#61537
-acetoxy ketones in good chemical and optical yields. The Bayer-Villiger oxidation of &
#61537
-acetoxy ketones with m-CPBA, CF3SO3H, and CH2Cl2, at rt gives the corresponding lactones without racemization. The phenyl moiety migrates selectively in order to form lactones. The mild hydrolysis of lactones affords phenolic &
#61537
-hydroxycarboxylic acid derivatives. Because of the high importance of pyrrole derivatives which exist in the structure of many natural products possessing biological activity beside their valuable feature of being versatile building blocks in organic synthesis and important starting materials for various synthetic transformations, a convenient method for the synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives starting from 1,3,-dicarbonyl compounds throuh acid catalyzed cyclization reaction is presented in the second part of the thesis. Alkylation of 1,3-dicarbonyl compound with propargyl bromide followed by one step cyclization with the introduction of primary amines in the presence of catalytic amount of trifluoroacetic acid (TFA) affords the corresponding pyrrole derivatives in high yields. The third part of the thesis describes the cyano-phosphorylation of various alkyl and aryl phosphonates in the presence of diethyl cyanophosphonate (DEPC) as the phosphorylating agent under the promotion of the KCN catalyst. Reaction of acyl phosphonates with DEPC forms the phosphonocyanohydrin-O-phosphates which are the important starting materials of quaternary &
#945
-hydroxy carboxylic acid and phosphonate containing &
#946
-aminoalcohol derivatives.
20
Chamala, Raghu Ram. "STUDIES TOWARD THE TOTAL SYNTHESIS OF (±)-α-YOHIMBINE BY DOUBLE ANNULATION." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_diss/78.
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The indole alkaloids, a class of natural products, have received much synthetic attention for years due to their diverse structures and interesting biological properties. We are particularly interested in synthesizing some of the yohimbine alkaloids extracted from the bark of a tall evergreen African tree (Corynanthe yohimbe, commonly known as fringe tree). Yohimbine and its stereoisomers have been tempting targets for synthetic organic chemists for more than fifty years. These compounds feature a pentacyclic ring system with two heteroatoms and five stereogenic centers.
Broadly, the fifteen different synthetic approaches that led to the successful completion of yohimbine alkaloids relied only on two basic synthetic strategies. In the first strategy, the last step almost always was the formation of the C(2)-C(3) bond by either Pictet-Spengler reaction or by Bischler-Napieralski reaction with the concomitant formation of the C ring. The second strategy involved the annulation of the D and E rings onto the intact ABC ring system.
With our double annulation methodology, herein, we report a completely different synthetic approach to access the yohimbine alkaloids, and our disconnections are not even remotely close to the synthetic designs used in the past. Our key steps include double Michael reaction to construct the E ring, an intramolecular cyclization to construct the D ring, and finally, the functionality on the D ring can be elaborated to form the C ring of the yohimbine alkaloids.
21
Ljungkvist, Oskar. "Mechanochemistry : C-H arylation and annulative π-extension reactions attempted inball mill." Thesis, Uppsala universitet, Institutionen för kemi - BMC, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-382088.
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22
Sun, Wei. "Studies on aminocyclobutenone rearrangements and a new C-H activation annulation reaction leading to N-heterocycles." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/413847/.
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This thesis describes study of aminocyclobutenone rearrangements. Thermal and photo rearrangements of cyclobutenones have become established as useful methods for the synthesis of quinones, naphthoquinones and furanones, some of which show useful biological activity. Though widely used, little is known about the behaviour of aminocyclobutenones. Herein, thermolyses and photolyses of aminocyclobutenones under continuous flow were studied in depth. DFT calculations were employed to bring greater understanding to our experimental results and identify new avenues for study. In this work we also introduce a novel metal-free C-H activation and annulation reaction which could lead to N-heterocycles. Experimental work and DFT calculations were performed to understand the nature of this unusual reaction. We also delineated the regioselectivity and diastereoselectivity of this reaction. A new rearrangement of cyclobutenones leading to 2-oxobut-3-enamides at low temperature has also been introduced. This new rearrangement offers a short and efficient route to synthesise highly substituted furans.
23
Friesen, Richard William. "Annulations leading to bicyclic dienes : Diels-Alder reactions of (some of) the dienes and dolastane diterpenoid syntheses." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28781.
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The preparation of bicyclic dienes of the general structures (72), (82), (83) and (162) is described. These materials have been prepared via a novel annulation sequence involving (a) the alkylation of various carbonyl containing substances with the donor acceptor reagents (43), (44), (108)-(114) and (154), (b) the conversion of the alkylation products into the enol triflates, and (c) the palladium(O) catalyzed intramolecular coupling of the enol triflate-vinylstannane moieties via either a "one" or "two pot" process.
The Diels-Alder reactions of the "parent" bicyclic diene (75), the cisoid cis diene (145) and the cisoid trans diene (146) are described. Four basic questions regarding the face selectivity, regioselectivity, stereoselectivity and comparative reactivity of the dienes in the formation
of the Diels-Alder adducts of general structure (174) are addressed.
The annulation sequences described above have been applied to the first total syntheses of the dolastane diterpenoids (±)-(14S)-dolasta-1(15),7,9-trien-14-ol (239) and (±)-amijitrienol (242). Thus, the substituted cycloheptanone (262), prepared in seven steps from the commercially available material (261), was converted via a series of transformations, including the newly developed annulation process, into the bicyclic diene (264). Introduction of the two appendages to (264) proceeded stereoselectively to provide the keto vinylstannane (265). Ring closure was effected with the desired stereochemistry to yield (±)-(239). A reduction, deprotection sequence afforded the ketone (249) from the diene ketal (263). A series of three steps involving an aldol condensation, Swern oxidation and stereoselective methylation provided the diketone (290). Chemo- and stereoselective reduction of (290) followed by protection of the alcohol moiety yielded the silyl ether (303). Cyclization, according to the methodology described herein, and deprotection of the silyl ether moiety produced (±)-(242). [Formula Omitted]Science, Faculty of
Chemistry, Department of
Graduate
24
Li, Jihui. "Copper-Catalyzed Domino C-N Bond Formation for Synthesis of N-Containing Compounds (Benzimidazoles, Imidazoles, and Guanidines) - Approach toward Total Synthesis of Natural Product Raputindoles." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112130.
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Cette thèse est constituée de trois parties : 1) Le contexte bibliographique, 2) le développement de réactions domino cupro-catalysées et 3) une approche vers la synthèse totale des raputindoles.La première partie introduit d’abord le concept de réactions domino ainsi que leurs applications, puis les réactions catalysées par du cuivre permettant de former des liaisons C-N sont passées en revue en incluant les couplages de Ullmann, Goldberg et de Chan-Lam, les séquences d’activation oxydante de liaisons C-H/formation de liaison C-N, l’insertion de nitrènes et l’hydroamination de liaisons C-C multiples. En se basant sur ces réactions élémentaires permettant de former une liaison C-N unique, les développements récents de réactions domino sont ensuite détaillés.La deuxième partie peut être subdivisée en 3 sections : 1) la synthèse de benzimidazoles, 2) la synthèse d’imidazoles and 3) la synthèse de guanidines. Un rappel des méthodes existantes pour la synthèse de ces motifs est proposé dans chaque section. Notre travail, basé sur la formation de liaisons C-N multiples selon une séquence cupro-catalysée domino, est ensuite détaillé. Celui-ci nous a permis d’aboutir au développement de voies d’accès aux benzimidazoles, en utilisant une réaction séquentielle catalysée par du cuivre en présence d’oxygène à partir d’acides boroniques et d’amidines, à la synthèse d’imidazoles par une réaction de di-amination d’alcynes vrai par des amidines et à l’obtention de guanidines et de 2-aminobenzimidines par une réaction à 3 composant. Ces réactions domino montrent une bonne efficacité et permettent d’assembler des hétérocycles à partir de précurseurs aisément accessibles.La dernière partie est consacrée à la synthèse des raputindoles. La structure, les activités et les réactions clé pour la construction de ces alcaloïdes sont discuté d’abord, nous amenant à proposer une rétrosynthèse pour accéder à ces molécules. Les réactions qui ont retenues notre attention pour construire ces molécules sont une annelation [3+2] irido-catalysée d’acides o-formylarylboronique et de 1,3-diènes, la synthèse de Leimgruber-Batcho pour obtenir des indoles et une séquence d’alkylboration-protodéboration. A partir de cela 3 stratégies ont été évaluées, montrant que l’accès à ce type de composé naturel est envisageable en combinant ces étapesThis thesis consists in three parts: bibliographic background, copper-catalyzed reactions for synthesis of N-containing compounds, approach to the synthesis of raputindoles.The first part introduces the domino reactions and their applications, then, copper-mediated reactions for construction of C-N bond formation are reviewed including Ullmann, Goldberg and Chan-Lam coupling, oxidative C-H activation/C-N formation, insertion of nitrenes and carbenoids, and hydroamination of multi-C-C bonds. This can be used as guides to design domino reaction. Following these copper-mediated single C-N bond formation reactions, recent developments of copper-catalyzed domino reactions for synthesis of heterocycles are described.The second part can be divided into three sections: 1) synthesis of benzimidazoles, 2) synthesis of imidazoles and 3) synthesis of guanidines. Each section summarizes the existing methods used for their synthesis. Following it, our synthetic work involving copper-catalyzed C-N bond formation domino reactions is discussed in detail. Our objectives include the synthesis of benzimidazoles through copper-catalyzed sequential reaction of benzamidines and boronic acids, synthesis of imidazoles via copper-catalyzed domino reaction of benzamidines and acetylenes, and synthesis of guanidines and 2-aminobenzimidazoles by Cu-catalyzed three-component reaction of cyanamides, boronic acids and amines. These copper-catalyzed domino reactions show high efficiencies from readily available and simple starting materials.The last part is about the total synthesis of raputindoles. The structure and bioactivities of raputindoles and key reactions for the total synthesis of raputindoles are introduced first, the synthetic strategies are then proposed on basis of relative synthetic methods. The key reactions we use for the synthesis of raputindoles are iridium catalyzed [3+2] annulation of o-formylarylboronic acids and 1,3-dienes, Leimgruber-Batcho indole synthesis, transition-metal catalyzed SN2 substitution and alkylborylation-protondeborylation. According to the three strategies we proposed, lots of relative reactions were investigated. The results show that it is possible to synthesize the raputindole molecules based on the iridium catalyzed [3+2] annulation of 2-formylarylboronic acids and 1,3-dienes
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Nagamoto, Midori. "Iridium-Catalyzed Atom Economical Transformations of Unsaturated Hydrocarbons." Kyoto University, 2018. http://hdl.handle.net/2433/232279.
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Kambale, D. A. "Π -activation triggered cascade annulations reactions of alkynols: application in construction of ketal-lactones related to bioactive natural products." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2021. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/6006.
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Akca, Nazmiye Bihter. "Synthesis Of 2-aminopyrrole-3-carboxylates Via Zinc Perchlorate Mediated Annulation Of Alpha-cyano-gamma-ketoesters With Amines." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609715/index.pdf.
Full textAbstract:
2-Aminopyrrole-3-carboxylate derivatives are important starting materials for biologically active compounds like pyrrolotriazole, pyrrolotriazine so their synthese has great importance in the synthetic organic chemistry.
There are only two methods for the synthesis of 2-aminopyrrole-3-carboxylates in the literature. Therefore, there is a great need for the design and development of a new method for the synthesis of 2-aminopyrrole-3-carboxylates.
In this work, 2-aminopyrrole-3-carboxylate derivatives were synthesized starting from cyano acetic acid ethyl ester with a new method. In the first step, cyanoacetic acid ethyl ester was
alkylated with bromo acetone in the presence of NaH. Then, obtained gamma-ketoester was reacted with primary amines in the presence of catalytic amount of zincpechlorate (Zn(ClO4)2). As a result, 2-aminopyrrole-3-carboxylate derivatives were obtained. Cyanoacetic acid ethyl ester was also alkylated with various bromo acetophenone derivatives in the presence of DBU
(1,8-Diazabicycloundec-7-ene). As a result of these reactions, different gamma-ketoesters were obtained. The reaction of these gamma-ketoesters with primary amines in the presence of catalytic amount of Zn(ClO4)2 concluded with 2-aminopyrrole-3-carboxylate derivatives.
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Cavitt, Marchello Alfonzo. "Stress relief: Exercising Lewis acid catalysis for donor-acceptor cyclopropane ring-opening annulations, a basis for new reaction methodologies." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54448.
Full textAbstract:
Nature’s biodiversity is complex and filled with beauty and wonder which are all observable on the macroscopic scale. This exquisiteness of nature’s intricacies are mirrored on the molecular level such that substances, large or small, are assembled to serve as signaling molecules, protective agents, and fundamental composites of higher-order frameworks for the operation and survival of life. Over the years, chemists have isolated and synthesized these molecules, known as natural products, to understand and evaluate their functions in biology and potential for medicinal applications.
Although bioactive natural products demonstrate medicinal promise, poor pharmacological effects require further derivatization because semisynthesis is not sufficient to refine adverse pharmacokinetics. For some active molecules, isolation results in poor yields. In addition to small quantity isolation, many natural products, reflecting the immense complexity of biology itself, pose difficult synthetic challenges to organic chemists because of skeletal heterogeneity, stereochemical complexity, and substitution divergence. As a result of these synthetic obstacles to natural product utilization, improvements are needed in current chemical approaches, and new innovative methodologies for synthesis and chemical space exploration are necessary.
Pharmaceutically relevant frameworks, natural products, and synthetic biologically active molecules are comprised of polycarbocyclic and heterocyclic scaffolds. Traditionally, cycloadditions, transannular transformations, and annulation reactions serve as powerful methods for polycyclic formation. In order to assemble diverse polycycles, donor-acceptor cyclopropanes are useful, versatile synthetic equivalents for C-C bond formations. By taking advantage of the strain within these unique, polarized systems, differing molecular architectures can be accessed directly to perform contemporary organic synthesis. Moreover, the donor-acceptor cyclopropanes initially utilized in these studies provided a fundamental basis for new methods to synthesize other relevant scaffolds. Unique, efficient, Lewis acid-catalyzed intramolecular cyclization strategies for the construction of functionalized polycycles using Friedel-Crafts-type alkylation sequences are presented to expand the reaction repertoire of the molecular architect. Generally, products were formed from commercially-available starting materials in high yields with broad scope. The methodologies were demonstrated to be modular, operationally simple, and amenable to different substitution patterns and functional groups to afford tetrahydroindolizines, heteroaromatic cyclohexenones, hydropyrido[1,2-a]indoles, pyrrolo[1,2-a]indoles, pyrrolo[3,2,1-ij]quinolines, pyrrolizines, and tetrahydrobenzo[ij]quinolizines. To demonstrate the utility of the methodologies devised, progress toward, (±)-rhazinicine, a natural product, is discussed.
This dissertation is organized into six chapters: (1) an introduction, paradoxical stress and molecular strain’s utility in synthesis; (2) annulation reactions for the formation of heteroaromatic cyclohexenones; (3) hydropyrido[1,2-a]indole formation via an In(III)-catalyzed cyclopropane ring-opening/Friedel-Crafts alkylation sequence; (4) tetrahydroindolizine formation and progress toward the total synthesis of (±)-rhazinicine (5) pyrrolo[1,2-a]indole synthesis using a Michael-type Friedel-Crafts cyclization approach; and (6) a versatile protocol for the intramolecular formation of functionalized pyrrolo[3,2,1-ij]quinolines.
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Duvvuru, Deepti. "Development of phosphine catalyzed reactions : novel accesses to functionalized heterocycles." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112341.
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Nous effectué des réactions de cyclisations [3 +2] énantiosélectives entre des allénoates et des énones, catalyseées par des phosphines, donnant accès à des hétérocycles soufrés présentant des motifs moléculaires spirocycliques porteurs de nombreux centres asymétriques. De bons rendements chimiques et des bon excès énantiomériques ont été obtenus en utilisant le (S,S)-FerroPHANE comme le catalyseur chiral.D’autre part, nous avons développé de nouvelles réactions catalysées par les phosphines donnant accès à des hétérocycles azotés. En tenant de la réactivité des phosphines connue dans la Littérature, nous avons envisagé des substrats permettant la combinaison de différents processus catalytique.Des réactions de cyclisation [3+2], catalysées par les phosphines, entre des imines et des diènes conjugués, doublement activés à leurs extrémités, permet d’accéder en une seule étape à des 3-pyrrolines tri-substituées de manière diastéréosélective. Nous avons alors évalué les possibilités et limitation de cette nouvelle voie d’accès aux pyrrolines en mettant en jeu de toute une gamme de diènes et d’imines diversement fonctionnalisés.Nous avons ensuite étudié ce nouveau mode de cyclisation en utilisant des diènes où l’une des deux insaturations est inscrite dans un cycle. Dans le cas de ces substrats cycliques, des composés portant le motif hexahydroisoindol-4-one ont été obtenus de manière très efficace.Enfin, il a été montré que des diènes portant le motif coumarine réagissaient avec des imines en présence de quantités stœchiométriques de phosphine et d'eau pour donner lieu à un processus domino sans précédent: une réaction de aza-Morita-Baylis Hillman suivi d’une réaction de réduction. Ce processus s'est avéré très chimiosélectif et procède avec un excellent contrôle des configurations relatives des deux centres asymétriques contigus nouvellement formés.L’ensemble de ces études ont permis de mettre en valeur l’efficacité de la catalyse par les phosphines nucléophiles pour la formation d’hétérocycles soufrés et azotés, structurellement diversifiés et hautement fonctionnalisés, à partir de matières premières facilement accessiblesWe have applied the enantioselective [3+2] cyclisations between allenoates and enones, under phosphine catalysis, to the asymmetric synthesis of sulfides and sulfoxides displaying unprecedented spirocyclic molecular scaffolds and multiple stereocentres. Notably, good yields and e.e’s were obtained by using (S,S)-FerroPHANE as the chiral catalyst. Then, we established a highly diastereoselective oxidation procedure which converts the enantiomerically enriched spirocyclic sulfides into the corresponding sulfoxides. On the other hand, we have developed new phosphine promoted reactions for the synthesis of nitrogen heterocycles. From the known modes of action of phosphine nucleophiles, we have designed new combinations of properly functionalized substrates that have been processed in the presence of phosphorus catalysts. The [3+2] annulation reaction between imines and acyclic conjugated dienes, properly activated by electron withdrawing groups on both ends, affords a new efficient and diastereoselective approach to functionalized 3-pyrrolines, under phosphine catalysis. We have studied the scope and limitations of this strategy by considering a whole range of differently substituted dienes and imines. As an extension, we have also considered analogous cyclizations between imines and cyclic conjugated dienes in which one of the double bonds is embedded in a cyclic moiety which afforded the functionalized hexahydroisoindol-4-one derivatives. Coumarin derived dienes reacted however with stoichiometric amounts of phosphine and water to give an unprecedented domino process, i.e. a formal aza-Baylis Hillman-reduction sequence. The process proved to be highly chemoselective and allowed an excellent stereochemical control of the relative configurations of two, newly created, contiguous carbon centres.These studies have demonstrated that the phosphine catalysis affords simple and efficient methodologies for the synthesis of structurally diverse and highly functionalized heterocycles, starting from easily available starting materials
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RIBEIRO, CARDONA FRANCISCO MIGUEL. "Synthesis of new ab-ligands useful in diagnosis of alzheimer's disease." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2013. http://hdl.handle.net/10281/44989.
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Alzheimer’s disease is a chronic progressive neurodegenerative disease and is the most common form of dementia (estimated 50−60% of all cases), associated with loss of memory (in particular episodic memory), cognitive decline, and behavioural and physical disability, ultimately leading to death. Alzheimer’s disease is a complex disease, mostly occurring sporadically with no apparent inheritance and being the age the main risk factor. The production and accumulation of amyloid-beta peptide in the central nervous system is a key event in the development of Alzheimer’s disease.
This project is devoted to the synthesis of amyloid-beta ligands, fluorophores and blood brain barrier-transporters for diagnosis and therapy of Alzheimer’s disease. Different amyloid-beta ligands will be synthesized and their ability to interact with amyloid-beta plaques will be studied with nuclear magnetic resonance techniques and a process of lead optimization will be performed. Many natural and synthetic compounds able to interact as amyloid-beta ligands have been identified. Among them, a set of small molecules in which aromatic moieties seem to play a key role to inhibit amyloid-beta aggregation, in particular heteroaromatic polycyclic compounds such as tetracyclines. Nevertheless tetracyclines suffer from chemical instability, low water solubility and possess, in this contest, undesired anti-bacterial activity. In order to overcome these limitations, one of our goals is to synthesize tetracyclines analogues bearing a polycyclic structure with improved chemical stability and water solubility, possibly lacking antibacterial activity but conserving the ability to interact with amyloid-beta peptides. Known tetracyclines have in common a fourth cycle without an aromatic character and with different functionalisations. We aim to synthesize derivatives in which this cycle is represented by a sugar moiety, thus bearing different derivatisable positions or create derivatives in which we will increase or decrease the number of fused rings. In order to generate a potential drug-tool candidate, these molecules should also possess the correct chemical-physical characteristics. The glycidic moiety, not being directly involved in the binding, it assures further possible derivatizations, such as conjugation to others molecular entities (nanoparticles, polymeric supports, etc.), and functionalization with chemical groups able to modulate the hydro/lipophilicity. In order to be useful such compounds should perform their action within the brain, therefore they have to be able to cross the blood brain barrier, and to be somehow detected for diagnostic purposes.
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Ciccolini, Cecilia. "Synthesis of Mono and Poly-Heterocycles starting from 1,2-Diaza-1,3-Dienes (or precursors) as Building Blocks." Doctoral thesis, Urbino, 2020. http://hdl.handle.net/11576/2674162.
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Ashok, Sadani Amit, and 沙達尼. "Application of dicarbonyl compounds in stereoselective organocatalytic annulation reactions." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/91294995627764267246.
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博士國立中正大學
化學暨生物化學研究所
99
In traditional manner the organic reaction means linear and stepwise processes in which isolation and purification of key intermediates, these processes usually leads in the reduction of yields which implies the efficiency of the process. On the other hand the domino process could form several bonds in single sequence without isolating the intermediates, changing the reaction conditions, or adding reagents, thus the efficient manner with respect to the stepwise reactions. Also it allows access to a number of complex molecular structures with high stereocontrol in an efficient, atom-economical fashion. Recently, domino reactions have been catalyzed by chiral organic molecules, “organocatalysts”, to provide a variety of complex structures in an efficient and splendid manner. Amine catalysts activate carbonyls by an iminium ion or an enamine formation method, iminium ion formation increases the electrophilicity of the carbonyl carbons, and access to electrophilic conjugate addition reactions, while enamine formation increases the nucleophilicity, and facilitates nucleophilic addition and substitutions reactions. This thesis represents the domino reactions; “Application of dicarbonyl compounds in stereoselective organocatalytic annulations reactions” by enamine-iminium or iminium-enamine activation methods. We further demonstrated their applications towards the synthesis of biologically active intermediates. The second chapter deals with the organocatalytic double Michael reactions of 7-oxohept-2-enoate to nitrostyrene. The first conjugate addition and subsequent intramolecular cyclization afforded the highly functionalized cyclohexane carboester with four stereogenic centers with high diastereoselectivity and high enantioselectivity (>99% ee). Some adducts were transformed into the intermediates of the synthesis of (-)-α- and (-)-β-lycorane. The third chapter deals with the domino double Michael reactions of ethyl (E)-7-oxohept-2-enoate and α, β-unsaturated aldehydes which provides highly functionalized cyclohexane derivatives with excellent diastereoselectivities (>20:1 dr) and enantioselectivities (>99% ee). And some of the adducts were transformed into the important skeletons. The fourth chapter deals with organocatalytic Michael reaction of glutaraldehyde or 5-oxohexanal and α, β-unsaturated aldehydes followed by the subsequent intramolecular aldol condensation provided 2-arylcyclohex-3-ene-1,3-dicarbaldehydes in high diastereoselectivity and high enantioselectivity (>99% ee).
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Gilmore, Christopher Dennis. "Aryne Annulation Reactions Toward the Synthesis of Heterocyclic Molecules." Thesis, 2012. https://thesis.library.caltech.edu/6859/12/11_-_Outro-FINAL.pdf.
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The last decade has seen an outgrowth in the development of synthetic methodologies exploiting benzyne. The unique ability of this reactive intermediate to directly furnish ortho-difuntionalized aromatic systems first stoked interest in this research group as a possible partner in asymmetric arylation reactions. Since our initial forays, we have expanded our synthetic strategies to include bond insertions, cycloadditions, condensations, and multicomponent reactions. The first project discussed in this volume is the development of an aryne annulation strategy for constructing common, synthetically useful heterocyclic structures in a convergent manner. We have developed a convergent approach to indoles and indolines. Likewise, through an orthogonal functional group intallation upon an enamine substrate, isoquinolines, quinolines, and isoquinolones can all be accessed as well. In this manner, we have been able to generate an array of functionalized heterocycles, including some that are prohibited by traditional means of synthesis. We have also begun to understand some of the reactivity trends in this context for the elusive aryne reaction partner. The development of the aryne annulation strategy for the synthesis of isoquinolines directly led to the shortest reported total synthesis of the opiate alkaloid papaverine, and the tetrahydroisoquinoline anticancer antibiotic quinocarcin. Our more recent, ongoing efforts toward the synthesis of the bis-tetrahydroisoquinoline antitumor molecule jorumycin and its many structural relatives are detailed herein. Jorumycin has been targeted through a combination of aryne annulation and acyl-alkylation/condensation methodologies aimed at the synthesis of a functionalized bis-isoquinoline intermediate. Reduction of this key bis-isoquinoline to a bis-tetrahydroisoquinoline and subsequent lactamization will provide the pentacyclic core of jorumycin and related natural products in only three steps from simple isoquinoline building blocks. The final project described is the development of several different aryne multicomponent reactions to form novel carbo- and heterocyclic scaffolds, including iminoisobenzfurans, iminoindenones, dibenzoketocaprolactams, and 2-quinolones.
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Ghosh, Biki. "Enantioselective Annulation Reactions: From Fischer Indolization to de novo Arene Construction." Thesis, 2022. https://etd.iisc.ac.in/handle/2005/6014.
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In summary, we have developed the first decarboxylative [4+2]-annulation of ethynyl
benzoxazinanones with azlactones for the enantioselective synthesis of cyclic α-quaternary
α-acylaminoamides.25 This direct and modular approach combines dipolar copper-allenylidene
intermediates and enolates generated from azlactones under bifunctional tertiary aminourea
catalysis in a cooperative fashion. The resulting 3,4-dihydroquinolin-2-ones 3.43, bearing vicinal
tertiary and quaternary stereogenic centers, are formed as a single diastereomer with good to
excellent enantioselectivity. The products are densely functionalized and the synthetic versatility of
the terminal alkyne group is demonstrated through a number of synthetic elaborations. This reaction
represents the first direct catalytic enantioselective route to cyclic α-quaternary α-acylaminoamides
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Wu, Yun-Ching, and 吳昀靜. "Copper and Iron-Catalyzed Annulation Reactions for the Synthesis of Quinoline Derivatives." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/2x7a72.
Full textAbstract:
碩士國立清華大學
化學系所
105
Quinoline derivatives are abundant in nature. Quinoline scaffold plays an important role in drug development as their derivatives have shown excellent biological activities. As a result, many scientists try hard to develop a more efficient way to synthesize quinoline derivatives. In this thesis, we selected copper and iron catalysts because of their plentiful resources and cheaper prices. Two methods about quinoline synthesis are demonstrated here. Chapter 1 shows an approach toward the synthesis of quinolines via copper (II) promoted amines, formaldehyde, and internal alkynes for the intermolecular cycloaddition reaction. Chapter 2 gives a special method of synthesis quinolines via iron (III) catalyzed intermolecular cycloaddition and elimination reaction from imines and 1,4-epoxynaphthalene. Finally, this method was successfully applied to synthesize cinnolinium salts.
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Liu, Ching-Yuan, and 劉青原. "Combining furan annulation,heck,and sonogashira cross-coupling reactions leading to molecular wires." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/04690374952055178180.
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碩士國立臺灣大學
化學研究所
90
Bidirectioonal iterative synthesis of furan-containing oligomers of different conjugation lengths leading to molecular wires is reported. Furan and benzene alternating oligomers are prepared by using our usual furan annulation approach. When the divinyloligoaryl or dialkynyloligoaryl is used, dialdehyde can be conveniently constructed by Heck or Sonogashira cross-coupling reaction. Dialdehydes can be used for further extension of these conjugated systems. Attempts to annulate these dialdehydes with functionalized dithioacetals are found to be successful. Thus, incorporation of arylenes, double bonds, and/or triple bonds into these oligomeric systems is feasible by combining Heck or Sonogashira cross-coupling reaction with furan annulation procedure. This newly-developed synthetic strategy affords a convenient pathway for the fast construction of a variety of furan-containing oligomers toward molecular wires.
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KUPPUSAMY, RAMAJAYAM, and 藍加亞. "Rhodium and Cobalt-Catalyzed C–H Bond Functionalization and Annulation Reactions with Allenes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/99fda6.
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博士國立清華大學
化學系所
105
ABSTRACT Transition-metal catalyzed synthetic methods are the most important tools of modern organic synthesis. Particularly, direct C–H functionalization by utilizing readily available π-components is an attractive methodology to synthesize natural products and bioactive skeletons in a single step. It is an atom- and step-economical method which is highly urged as one of the green processes. In this regard, this thesis describes three new reactions that focus on the transition-metal catalyzed C–H bond functionalization reactions with allenes. For convenience and better understanding, the thesis is divided into three chapters. These three chapters describe Rh(III) and Co(III)-catalyzed C–H bond functionalization and annulation reactions with allenes. Chapter 1 describes a Rh(III)-catalyzed [4+1] annulations of 2-hydroxy- and 2-aminobenzaldehydes with allenes. The reaction proceeds via aldehyde C–H bond activation, allene insertion and nucleophilic addition followed by β-hydride elimination to afford functionalized 3-coumaranones and 3-indolinones in excellent yields. Chapter 2 deals about Co(III)-catalyzed phenolic OH-assisted C–H bond functionalization of 2-vinylphenols with allenes to afford [5+1] annulation product. The reaction proceeds via vinylic C–H bond activation, allene insertion and unusual intramolecular regioselective phenoxide addition followed by β-hydride elimination to afford 2,2-disubstituted 2H-chromenes in excellent yields. This is the first time that allenes have been used as the coupling partners in cobalt-catalyzed C–H activation reactions. Chapter 3 explains about a Co(III)-catalyzed [3+3] annulation of N-Phenylacetamides with Allenes. The reaction proceeds via aromatic C–H bond activation, allene insertion, followed by β-hydride elimination and 1,4-addition reaction affords a functionalized 1,2-dihydroquinolines in excellent yields. Isolation of acyclic diene intermediate clearly explains the reaction pathway.
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Luo, Ching Zong, and 羅慶宗. "Rhodium and Ruthenium-Catalyzed Synthesis of Planar Ammonium Salts via C–H Bond Activation and Annulation Reactions." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/30526312205247284409.
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博士國立清華大學
化學系
103
In recent years, transition metal-catalyzed C–H bond activation and annulation reactions were emerged as an important strategy in the synthesis of natural product, bioactivity molecules and material compounds. In this context, our group also focus on the hot research field of C–H bond activation reaction. The thesis concentrated on the synthesis of polycyclic pyridinium, quinolizinium, and pyridinium salts by rhodium- and ruthenium- catalyzed C–H bond activation and annulation reactions. In addition, copper promoted quinoline synthesis from benzylazides and alkynes through arylmethyl azides rearrangement is demonstrated in the final chapter. Chapter 1 describes an efficient and convenient method for the synthesis of highly substituted polycyclic pyridinium salts from various 2-arylpyridines and alkynes via a Rh(III)-catalyzed C–H bond activation and annulation reactions under an atmosphere of O2. The proposed mechanism is supported by the isolation of a five membered rodacycle. Primary photophysical studies were also performed on the new pyridinium salts compound in OLED materials. Chapter 2 introduces effectual methods to the synthesis of quinolizinium salts from 2-vinylpyridines and alkynes via Rh(III) or Ru(II)-catalyzed C–H activation and annulation reactions. The present quinolizinium salts can be readily converted to the corresponding tetrahydroquinolizinium compounds by hydrogenation. Chapter 3 elaborates a synthetic method for highly substituted pyridinium salts from the multicomponent reaction of vinyl ketones, amines, and alkynes using a rhodium catalyst. The catalytic reaction proceeds via an in situ generated imine-assisted Rh(III)-catalyzed vinylic C–H activation reaction. Synthesis of highly substituted pyridines from pyridinium salts also was demonstrated. Chapter 4 illustrates a new route for quinolizinium salts synthesis from 2-ethylpyridines and alkynes using cooperative catalysis by copper and rhodium with high yields, broad substrate scope and functional group tolerance. Detailed mechanistic studies suggest that the 2-vinylpryridine is formed in situ from 2-ethylpyridine by a copper promoted C(sp3) –H hydroxylation followed by dehydration. Later, a Rh(III)-catalyzed pyridine directed vinylic C(sp2) –H activation and [4+2] annulation with alkynes provide the final product. Chapter 5 shows a technique toward the synthesis of quinolines via copper promote azide rearrangement and intermolecular cycloaddition reaction with internal alkynes. In addition, the method was applied to the synthesis of biological active quinoline compounds.
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Sripanom, Lertnarong [Verfasser]. "Studies on the synthesis of extended π-systems [pi-systems] : Willgerodt-Kindler domino annulation and SNAr-reactions / Lertnarong Sripanom." 2009. http://d-nb.info/99786964X/34.
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Lee, Jihoon. "Application of the silicon-directed annulation reactions to the total synthesis of natural products & studies directed toward the total synthesis of leiodolide A: preparation of the C13-C29 fragment." Thesis, 2013. https://hdl.handle.net/2144/14144.
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Brevisamide was isolated from the red tide dinoflagellate Karenia brevis in 2007. Key features of brevisamide include a substituted tetrahydropyran core and conjugated 3,4-dimethylhepta-2,4-dienal side chain. Total synthesis of brevisamide was highlighted by a stereoselective [4+2]-annulation of a (Z)-crotyl silane to furnish the substituted pyran core and Negishi cross-coupling to construct the conjugated dienal side chain. Successful application of the silane-based annulation methodology provided brevisamide in overall 17 steps and 6.4% overall yield from the known (Z)-crotyl silane.
Isatisine A was isolated from the leaf and roots of Isatis indigotica in 2007. Total synthesis of isatisine A commenced with the development of a silyl-directed Mukaiyama-type [3+2]-annulation of an ethoxy allylsilane to construct a tetrahydrofuran core. [3+2]-Annulation reaction of an ethoxy allyl silane with 2-bromocinnamylaldehyde afforded the furan core as a single diastereomer. Further substrate-controlled indole addition and intramolecular copper(I)-mediated amidation provided (+)-isatisine A in overall 12 steps.
One-pot Diels-Alder/annulation sequence was developed utilizing a silane-substituted 1,3-diene to give a fused-cyclic scaffold. In this reaction sequence, initial Lewis-acid-promoted Diels-Alder reaction between the silyl-substituted diene and a naphthoquinone constructed an intermediate cyclic allylsilane, and subsequent addition of aldehyde and Lewis acid triggered the annulation to construct a complex cyclic compound with high diastereoselectivity. This one-pot three component reaction sequence allowed for a simple access to various fused-polycyclic compounds, which bear a tetrahydropyran core.
Leiodolide A was isolated from the deep-water marine sponge Leiodermatium. Leiodolide A was found to be significantly cytotoxic against HCT-116 human colon carcinoma with IC50 values = 1.4 ug/mL (2.5 uM). Since the natural product leiodolide A was found to comprise less than 0.001% of the dry weight of the sponge, establishing an efficient synthetic method to provide a significant amount of the natural product would be valuable to further biological studies. Our effort to synthesized upper fragment of leiodolide A was conducted through a series of cross-coupling reactions involving Stille coupling. Although proper conditions for the oxidation of (Z)-olefin to introduce the contiguous C15-17 triol system in leiodolide A were not achieved, this synthetic pathway would be useful in the total synthesis of leiodolide A.
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Ramadoss, Boobalan, and 布巴倫. "Ruthenium-catalyzed C–H Alkynylation Reaction of Aromatic Amides with Hypervalent Iodine-Alkyne Reagents and Cobalt-Catalyzed Annulation Reactions of Amides with Allenes via C–H Bond Activation." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/hr4s5y.
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Jan, Rei-Hau, and 詹瑞豪. "Organocatalytic enantioselective cascade Michael-Michael-Wittig reactions of phosphorus ylides: one-pot synthesis of the all-cis trisubstituted cyclohexenecarboxylates via the [1+2+3] annulation." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/05857033837138680501.
Full textAbstract:
碩士國立中正大學
化學所
98
The stereoselective synthesis of (4S,5R,6S)-ethyl 5-nitro-4,6-diphenylcyclohex-1-carboxylate has been achieved by an organocatalytic enantioselective cascade Michael-Michael-Wittig reaction of (carbethoxymethylene)triphenylphosphorane, trans-β-nitrostyrene and trans-cinnamaldehyde. The reaction conditions in the synthesis of all-cis trisubstituted cyclohexenecarboxylate derivatives have been modified to optimize the yields and stereoselectivities. Subsequently, a series of all-cis trisubstituted cyclohexenecarboxylate derivatives was synthesized.
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Yeh, Li-Hsuan, and 葉俐萱. "Late transition-metal catalyzed cascade annulation reaction." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/z76cw9.
Full textAbstract:
碩士淡江大學
化學學系碩士班
107
We use cyanation reaction, condensation reaction and reduction-oxidation reaction to synthesize the starting materials. Try to optimize the reaction condition of copper catalyst, then screen other kinds of metal. We find that palladium can give high yield of product. Again we optimized the reaction condition of palladium and synthesize a serial of Indolo[2,3-b]quinolone compounds up to 19 cases.
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McKenzie, Jean Mary-Anne. "Application of the Noyori annulation reaction to the cephalotaxine spirocycle." Thesis, 2001. http://hdl.handle.net/10413/3008.
Full textAbstract:
Cephalotaxine is a naturally occurring alkaloid which is the structural motif of a number of compounds which have shown promising anti-cancer properties. This fact together with its relatively complex pentacyclic structure, which incorporates an azaspirocycle annular to a benzazepine moiety, has resulted in its popularity as a synthetic target. The aim of this project was to synthesise the azaspirocycle of cephalotaxine using a Noyori annulation method involving the reaction of an enamine and an a,a' -dibromo ketone in the presence of Fe2{CO)9. In the first attempt the reaction of l-benzyl-2-methylenepyrrolidine (117) with methyl 2,4-dibromo-3-oxobutanoate (116) proved to be unsuccessful, the electron withdrawing ester functionality of methyl 2,4-dibromo-3-oxobutanoate (116) being unable to stabilise the intermediates formed during the reaction and thus resulting in its failure. Reaction of l-benzyl-2-methylenepyrrolidine (117) and 2,4-dibromo-3-pentanone (114) resulted in the formation of an azaspirocycle though in an extremely poor yield and the reaction was deemed inefficient for the synthesis of the cephalotaxine spirocycle. Finally, reaction of 2-(l-benzyl-2-pyrrolidinylidene)acetonitrile (129) and 2,4-dibromo-3-pentanone (114) resulted in the successful synthesis of a novel azaspirocycle. The product, l-benzyl-7,9-dimethyl-8-oxo-1-azaspiro[4.4]nonane-6-carbonitrile (130), contained four stereogenic centres and one of the diastereomers was successfully crystallised out. The X-ray structure in conjunction with NOESY NMR experiments showed the relative stereochemistry to be 5s', 6s', 7s', 9s'. Significant progress was made in the application of this methodology to the construction of the cephalotaxine pentacyclic skeleton with the synthesis of a novel lactam, 1-[2-(6-iodo-I,3-benzodioxol- 5-yl)ethyl]-2-pyrrolidinone, being achieved. In the course of this work a novel compound, 2-(6-Iodo-1 ,3-benzodioxol-5-yl)ethyl 4-methylbenzenesulfonate (98), was also synthesised and its X-ray structure revealed it to be conformationally interesting. As a result a conformation analysis study was carried out on this compound as well as 2-(6-Iodo-I,3-benzodioxol- 5-yl)ethyI 4-nitrobenzenesulfonate (15a). The Noyori annulation reaction was not implemented in the route to the basic pentacyclic structure of cephalotaxine due to time constraints, however synthesis of analogues of cephalotaxine and other alkaloids possessing azaspirocycles should now be possible based on the methodology developed in this project.Thesis (M.Sc.)-University of Natal Pietermaritzburg, 2001.
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Schulman, Jacqueline Madeleine. "Synthesis of 1,2,3-Triazole-fused Heterocycles via Palladium Catalyzed Annulation of 5-Iodotriazoles." Thesis, 2011. http://hdl.handle.net/1807/31434.
Full textAbstract:
Increasing attention has recently been directed toward 1,2,3-triazole-containing compounds. With their unique properties and excellent stability, 1,4-disubstituted triazoles are readily accessible via the copper catalyzed azide alkyne cycloaddition (CuAAC). As compounds containing fused triazoles become common in pharmaceutical targets and biologically active substances, new strategies to synthesize this class of molecules are highly desirable.
An efficient and highly modular approach toward the synthesis of three different heterocyclic motifs containing fused 1,2,3-triazoles is reported. The synthesis involved a Pd-catalyzed annulation of 5-iodo-1,2,3-triazoles, which were prepared by a Cu(I)-catalyzed cycloaddition of iodoalkynes and azides. This work demonstrates the versatility of iodotriazoles in Heck reactions and in direct arylations.
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Hung, Chen-Hsun, and 洪振勛. "Ruthenium, Iron and Nickel-Promoted Annulations and Coupling Reactions using Alkyne as a Substrate." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/x8b6ts.
Full textAbstract:
博士國立清華大學
化學系所
105
New synthetic methods of transition metal-catalyzed annulation and coupling reaction with alkynes using ruthenium, iron and nickel as catalysts are described in this thesis. In first chapter, ruthenium-catalyzed C－H bond activation and [3+2] annulation from N-tosylarylimines and alkynes to synthesize substituted N-tosylindenamine is described. The proposed mechanism involves an intramolecular insertion of the C=NTs group into the C-Ru bond instead of forming [4+2] annulation product via reductive elimination. The second chapter reveals iron-promoted oxidative [4+2] annulation of arylglyoxals with alkynes for the synthesis of substituted 1,2-naphthoquinones at room temperature in short time. Interestingly, the products show an unusual pseudo-migration of the substituent on the arene ring of arylglyoxals. In the proposed mechanism, Fe(III)-promoted electrophilic addition of the vinyl cation to the ipso carbon of the aryl group to give a spiral intermediate and then migration of the keto carbon to the ortho carbon is proposed as key steps. In the final chapter, an economically efficient synthetic method of multi-substituted acrylic acid via nickel-catalyzed carbomagnesiation with alkynes and Grignard reagents and then fixation of carbon dioxide is developed. The catalytic reaction proceeds well with board substrate scopes and high regioselectivity. An alternative method for fixation of CO2 into organic compounds is feasible with this synthetic method and it proceed in gram scale without loss of efficiency in the same time.
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Gerasyuto, Aleksey Igorevich. "Development of intramolecular aza- [3 + 3] annulation reaction and its applications in natural product synthesis." 2007. http://www.library.wisc.edu/databases/connect/dissertations.html.
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You, Ruei-Yi, and 游瑞益. "Preparation of Chiral α-Phosphono α,β-Alkenoates and Application into Michael Addition Annulation Reaction." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/19265831436958423783.
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陳旻賢. "Cobalt-Catalyzed Highly Stereoselective [3+2] Annulation Reaction for the Synthesis of Aminoindane- and Indene Derivatives." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/vqh6aq.
Full textAbstract:
博士國立清華大學
化學系
102
In this thesis, we successfully develop cobalt-catalyzed [3+2] annulation reactions of imine with unsaturated bonds and synthesize aminoindane-and indenes derivatives with efficiency. By these methodologies, we can construct aminoindane or indene skeletons in one step and it is also powerful synthetic methods for the synthesis of relative aminoindane or indene natural product and drugs. In chapter 2, we develop cobalt-catalyzed [3+2] annulation of 2-iminoarylboronic acids with conjugate alkenes to synthesize aminoindane carboxylate derivatives with high chemo-and diastereoselectivity. In chapter 3, we extend the result of chapter 2 and synthesize aminoindene derivatives by cobalt-catalyzed [3+2] annulation of 2-iminoarylboronic acids with alkynes. Furthermore, we combine PHOX chiral ligands which are prepared from commercial available amino acids in the cobalt catalysis reaction and generate a series of chiral aminoindenes with high regio-and enantioselectivity. In the final chapter, based on our cobalt catalysis system of aryl halides with other substrates experience before, we develop cobalt-catalyzed asymmetric [3+2] annulation of 2-iminoarylbromides with alkynes to construct chiral aminoindenes. In this reaction, we can prepare multi-substituted chiral aminoindenes with good to excellent regio-and enantioselectivity. Besides, we can learn more about the relative position of chiral cobalt complex and substrates in the reaction environment via absolute configuration determination.
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Chen, Yan-Fu, and 陳彥甫. "Copper-catalysed cascade reaction involving addition of nitrile and annulation to form the phenanthridinone and phenanthridine derivatives." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/43406745722673283930.
Full textAbstract:
碩士淡江大學
化學學系碩士班
102
The 1st Part: copper-catalyzed cascade reaction of C–O and C–N bond coupling. This method efficiently provides poly-substituted (NH)- phenanthridinones in moderate to good yields with tolerance of a wide variety of substrates. The 2st Part: copper-catalyzed annulation reaction involving addition of the Grignard reagent to nitrile and C–N bond coupling. This method efficiently provides poly-substituted phenanthridines in moderate to good yields with tolerance of a very wide variety of substrates.