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Letteratura scientifica selezionata sul tema "Heterocycles"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 9 novembre 2024

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Articoli di riviste sul tema "Heterocycles"

Zhu, Yannan, e You Huang. "Organocatalyzed [3+3] Annulations for the Construction of Heterocycles". Synthesis 52, n. 08 (5 febbraio 2020): 1181–202. http://dx.doi.org/10.1055/s-0039-1690810.

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Six-membered heterocyclic systems are widely distributed in many natural products and pharmaceuticals, and the construction of highly functionalized six-membered heterocyclic compounds is an important topic in modern organic synthesis. Organocatalyzed [3+3] annulations represents an important method for assembling a substantial variety of six-membered cycles that contain one or more heteroatoms. This review describes the development of organocatalyzed [3+3] annulations for the synthesis of six-membered heterocycles, including organocatalysis using secondary amines, tertiary amines, phosphines, chiral phosphoric acids and N-heterocyclic carbenes.1 Introduction2 Secondary Amine Catalyzed [3+3] Annulations2.1 Synthesis of Nitrogen Heterocycles2.2 Synthesis of Oxygen Heterocycles2.3 Synthesis of Sulfur Heterocycles3 Tertiary Amine Catalyzed [3+3] Annulations3.1 Catalysis through Multiple Hydrogen-Bonding Interactions3.2 Catalysis of Tertiary Amines as Lewis Bases4 Phosphine-Catalyzed [3+3] Annulations4.1 Synthesis of Nitrogen Heterocycles4.2 Synthesis of Oxygen Heterocycles4.3 Synthesis of Heterocycles Containing Two or More Heteroatoms5 Chiral Phosphoric Acid Catalyzed [3+3] Annulations5.1 Synthesis of Nitrogen Heterocycles5.2 Synthesis of Heterocycles Containing Two or More Heteroatoms6 N-Heterocyclic Carbene Catalyzed [3+3] Annulations6.1 Synthesis of Nitrogen Heterocycles6.2 Synthesis of Oxygen Heterocycles6.3 Synthesis of Heterocycles Containing Two or More Heteroatoms7 Conclusion and Outlook

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Andres, C. J., Derek J. Denhart, Milind S. Deshpande e Kevin W. Gillman. "Recent Advances in the Solid Phase Synthesis of Drug Heterocyclic Small Molecules". Combinatorial Chemistry & High Throughput Screening 2, n. 4 (agosto 1999): 191–210. http://dx.doi.org/10.2174/1386207302666220204193145.

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Abstract: Because of their synthetic challenge, broad range of physical I chemical properties, and diverse biological activities, heterocycles continue to be of interest to both the academic and industrial chemist. This review covers recent advances in the solid phase synthesis of drug-like heterocyclic small molecules. Syntheses which form the heterocycle on the solid phase are emphasized; syntheses in which a preformed heterocycle is functionalized on the solid support have been omitted. The majority of references are from publication year 1999. This review should be of interest to anyone involved in, or contemplating the solid phase synthesis of small molecule drug-like heterocycles, especially for combinatorial chemistry applications.

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Luna, Isadora Silva, Rayssa Marques Duarte da Cruz, Ryldene Marques Duarte da Cruz, Rodrigo Santos Aquino de Araújo e Francisco Jaime Bezerra Mendonça-Junior. "1,4-Dithiane-2,5-diol: A Versatile Synthon for the Synthesis of Sulfur-containing Heterocycles". Current Organic Synthesis 15, n. 8 (17 dicembre 2018): 1026–42. http://dx.doi.org/10.2174/1570179415666180821154551.

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Background: 1,4-Dithiane-2,5-diol (1,4-DTD) is the stable dimer of α-mercapto acetaldehyde. This commercially available ambidentade compound is characterized as having in its chemical structure one group that acts as an electrophile and another that acts as a nucleophile, this permits its use as versatile and efficient synthon in synthetic heterocycle procedures. Objective: The aim of this review is to present synthetic applications of 1,4-DTD in heterocyclic chemistry and their applicability to the synthesis of bioactive compounds. Conclusion: Gewald reactions to obtain C-4 and C-5 unsubstituted 2-amino-thiophene derivatives; sulfa- Michael/Henry and sulfa-Michael/aldol sequences to obtain polysubstituted tetrahydrothiophenes, and other heterocyclic reactions that allow synthesizing several functionalized sulfur-containing heterocycles such as thiazolidines, oxathiazinoles and thiazoles are presented and discussed. The use of such heterocyclics in subsequent reactions allows obtaining various bioactive compounds including the antiretroviral lamivudine which is one of the examples presented in this review.

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Winne, Johan, Jan Hullaert, Bram Denoo, Mien Christiaens e Brenda Callebaut. "Heterocycles as Moderators of Allyl Cation Cycloaddition Reactivity". Synlett 28, n. 18 (27 luglio 2017): 2345–52. http://dx.doi.org/10.1055/s-0036-1588511.

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For the rapid elaboration of polycarbocyclic scaffolds, prevalent in many important families of terpenoid natural products, allyl cations derived from simple heterocyclic alcohols can be used as versatile reaction partners in both (4+3) and (3+2) cycloaddition pathways. Our recent progress in this area is outlined, pointing towards the untapped potential of heterocycles to act as reagents in novel or known but challenging organic transformations.1 Heterocyclic Reagents2 Cycloadditions and Allyl Cations3 Furfuryl Cations in Cycloadditions4 Heterocycle-Substituted Cations in Cycloadditions5 Mechanistic Considerations6 Conclusions and Outlook

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Rusu, Aura, Ioana-Maria Moga, Livia Uncu e Gabriel Hancu. "The Role of Five-Membered Heterocycles in the Molecular Structure of Antibacterial Drugs Used in Therapy". Pharmaceutics 15, n. 11 (29 ottobre 2023): 2554. http://dx.doi.org/10.3390/pharmaceutics15112554.

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Five-membered heterocycles are essential structural components in various antibacterial drugs; the physicochemical properties of a five-membered heterocycle can play a crucial role in determining the biological activity of an antibacterial drug. These properties can affect the drug’s activity spectrum, potency, and pharmacokinetic and toxicological properties. Using scientific databases, we identified and discussed the antibacterials used in therapy, containing five-membered heterocycles in their molecular structure. The identified five-membered heterocycles used in antibacterial design contain one to four heteroatoms (nitrogen, oxygen, and sulfur). Antibacterials containing five-membered heterocycles were discussed, highlighting the biological properties imprinted by the targeted heterocycle. In some antibacterials, heterocycles with five atoms are pharmacophores responsible for their specific antibacterial activity. As pharmacophores, these heterocycles help design new medicinal molecules, improving their potency and selectivity and comprehending the structure-activity relationship of antibiotics. Unfortunately, particular heterocycles can also affect the drug’s potential toxicity. The review extensively presents the most successful five-atom heterocycles used to design antibacterial essential medicines. Understanding and optimizing the intrinsic characteristics of a five-membered heterocycle can help the development of antibacterial drugs with improved activity, pharmacokinetic profile, and safety.

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Romero-Hernández, Laura L., Ana Isabel Ahuja-Casarín, Penélope Merino-Montiel, Sara Montiel-Smith, José Luis Vega-Báez e Jesús Sandoval-Ramírez. "Syntheses and medicinal chemistry of spiro heterocyclic steroids". Beilstein Journal of Organic Chemistry 20 (24 luglio 2024): 1713–45. http://dx.doi.org/10.3762/bjoc.20.152.

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There is compelling evidence that incorporating a heterocyclic moiety into a steroid can alter its pharmacological and pharmacokinetic properties, driving intense interest in the synthesis of such hybrids among research groups. In this review, we present an overview of recent synthetic methodologies, spanning the period from 2000 to 2023, for the preparation of spiro heterocyclic steroids. The compounds surveyed encompass four-, five-, six-, and seven-membered heterocycles appended to various positions of steroidal backbones, with spirocycles containing oxygen, nitrogen, and sulfur atoms being predominant. The outlined synthetic procedures emphasize the pivotal steps for constructing the heterocycles, often accompanied by a detailed account of the overall synthesis pathway. The review encompasses innovative compounds, including bis-steroids linked by a spiro heterocycle and steroids conjugated to heterocyclic moieties containing three or more (hetero)cycles. Moreover, many compounds are accompanied by data on their biological activities, such as antiproliferative, antimalarial, antimicrobial, antifungal, steroid antagonist, and enzyme inhibition, among others, aimed at furnishing pertinent insights for the future design of more potent and selective drugs.

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Slivka, Mikhailo, e Mikhailo Onysko. "The Use of Electrophilic Cyclization for the Preparation of Condensed Heterocycles". Synthesis 53, n. 19 (19 maggio 2021): 3497–512. http://dx.doi.org/10.1055/s-0040-1706036.

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AbstractCondensed heterocycles are well-known for their excellent biological effects and they are undeniably important compounds in organic chemistry. Electrophilic cyclization reactions are widely used for the synthesis of mono-heterocyclic compounds. This review highlights the utility of electrophilic cyclization reactions as an effective generic tool for the synthesis of various condensed heterocycles containing functional groups that are able to undergo further chemical transformations, such as nucleophilic substitution, elimination, re-cyclization, cleavage, etc. This review describes the reactions of unsaturated derivatives of different heterocycles with various electrophilic agents (halogens, arylsulfanyl chlorides, mineral acids) resulting in annulation of an additional partially saturated heterocycle. The electrophilic reaction conditions, plausible mechanisms and the use of such transformations in organic synthesis are also discussed. The review mainly focuses on research published since 2002 in order to establish the current state of the art in this area. 1 Introduction2 Electrophilic Cyclization Pathways Involving a Nitrogen Nucleophilic Center3 Electrophilic Cyclization Pathways Involving a Chalcogen Nucleophilic Center3.1 Sulfur Centers3.2 Oxygen Centers3.3 Selenium Centers4 Strategies and Mechanisms5 Conclusion

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Cui, Hai-Lei. "Recent Advances in DMSO-Based Direct Synthesis of Heterocycles". Molecules 27, n. 23 (2 dicembre 2022): 8480. http://dx.doi.org/10.3390/molecules27238480.

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Besides serving as a low-toxicity, inexpensive and easily accessible solvent, dimethyl sulfoxide (DMSO) has also been extensively used as a versatile reagent for the synthesis of functionalized molecules. Dimethyl sulfoxide can not only be utilized as a carbon source, a sulfur source and an oxygen source, but also be employed as a crucial oxidant enabling various transformations. The past decade has witnessed a large number of impressive achievements on the direct synthesis of heterocycles as well as modifications of heterocyclic compounds by applying DMSO as a reagent. This review summarized the DMSO-based direct heterocycle constructions from 2012 to 2022.

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Ābele, E., R. Ābele, Ļ. Golomba, J. Višņevska, T. Beresņeva e K. Rubina. "Oximes of Seven-Membered Heterocyclic Compounds Containing One Heteroatom". Latvian Journal of Chemistry 50, n. 3-4 (1 gennaio 2011): 205–22. http://dx.doi.org/10.2478/v10161-011-0071-7.

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Oximes of Seven-Membered Heterocyclic Compounds Containing One Heteroatom Literature data on the synthesis and structure of azepane, oxepane and thiepane oximes were reviewed. Synthesis of novel heterocycles from oximes of seven-membered heterocycles containing one heteroatom were described. Biological activity of oximes of seven-membered heterocycles with one heteroatom was also reviewed.

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Ābele, E. "Oximes of Seven-Membered Heterocyclic Compounds Containing Two Heteroatoms". Latvian Journal of Chemistry 51, n. 1-2 (1 gennaio 2012): 83–92. http://dx.doi.org/10.2478/v10161-012-0005-z.

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Oximes of Seven-Membered Heterocyclic Compounds Containing Two Heteroatoms Literature data concerning the synthesis and structure of diazepane, oxazepane and thiazepane oximes were reviewed. Synthesis of novel heterocycles from the oximes of seven-membered heterocycles containing two heteroatoms was described. Biological activity of oximes of seven-membered heterocycles with two heteroatoms was also reviewed.

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Tesi sul tema "Heterocycles"

Locke, Julie Myree, University of Western Sydney, College of Health and Science e School of Biomedical and Health Sciences. "Synthetic and conformational studies of hexahydropyrimidines and related heterocycles". THESIS_CHS_BHS_Locke_J.xml, 2003. http://handle.uws.edu.au:8081/1959.7/638.

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This thesis explores the synthesis and conformational behaviour of hexahydropyrimidines and related heterocycles, with particular emphasis on 5- hyrdohexahydropyrimidines. The conformational behaviour of these compounds was investigated using dynamic NMR spectroscopy, molecular modelling techniques and X-ray crystal structure analysis. The conformational behaviour of 5- hyrdohexahydropyrimidine, hexahydropyrimidine and their analogous oxygen compounds as well as a series of hexahydropyrimidines with various exocyclic substituents, were examined. The preferred conformations of all these compounds are attenuated by a combination of steric and electronic influences. These influences include intramolecular hydrogen bonding as well as anomeric and gauche interactions. The conformational behaviour of the selected seven membered benzodiazepine rings, which share structural characteristics with the six-membered 5- hyrdohexahydropyrimidines was also explored. The increased flexibility of the seven membered rings facilitates intramolecular hydrogen bonding, which in turn retards ring inversion in these systems
Doctor of Philosophy (PhD)

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Sheldrake, Paul J. "Complexed heterocycles". Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386622.

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Locke, Julie Myree. "Synthetic and conformational studies of hexahydropyrimidines and related heterocycles". Thesis, View thesis, 2003. http://handle.uws.edu.au:8081/1959.7/638.

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Hemmings, Philippa Rachel. "Nitrogen heterocycles from sugars". Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314823.

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Bedford, Simon Bernard. "Synthesis of oxygen heterocycles". Thesis, University of Nottingham, 1993. http://eprints.nottingham.ac.uk/13159/.

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In chapter one, the various methods of generating benzenoid orthoquinodimethanes are discussed and approaches to their heterocyclic analogues are also reviewed. The utility of ortho-quinodimethanes in organic synthesis is highlighted by examples of both inter- and intramolecular Diels-Alder cycloadditions as the key steps in the total synthesis of naturally occurring polycyclic systems. In chapter two, work aimed at the development of a rapid synthetic entry to heterocyclic quinodimethanes starting from ortho-methyl heterocyclic carboxylic acids is presented. To this end, the dianion of 3-methylbenzofuran-2-carboxylic acid (018) was used to facilitate the construction of a "benzylsilane type" precursor (038) which in turn when treated with fluoride base, resulted in the generation of benzofuran-2,3-quinodimethane (012). We were then successful in trapping this intermediate with reactive dienophiles to form a series of the corresponding tetrahydrodibenzofurans (042 to 049). We have been able, for the first time, to determine the regioselectivity in this reaction by performing an X-ray crystallographic analysis on the major isomer (046) arising from cyclization with methylvinylketone. Preliminary work on an intramolecular variant as well as other heterocyclic acids is also presented. Chapter three, deals with the extensive modern approaches to tetrahydrofurans, but concentrates on examples that exhibit 2,5-disubstitution. It is sub-divided into the methods which involve an electrophile induced cyclization and the numerous alternative ones which do not. Their relevance in Natural Product assembly, especially the polyether antibiotics, is appraised. Chapter four continues with studies which have already established that Z-3-silyloxy-5-alkenoic acids undergo efficient and highly stereoselective iodolactonizations leading to the Mevinic analogues and related valerolactones. We have now established that the iodolactonizations of Z- and E-3-silyloxy-5-alkenoic acids (174 and 131) both lead to trans-disubstituted valerolactones, which differ only in the stereochemistry of the iodine substituent (175 and 178). The possibilities of effecting etherifications of the related Z-3-hydroxy-5- alkenoates (106) are then examined. By simply blocking the carboxylate end of the hydroxy-5-alkenoic acids involved in the above reactions it was found that under iodolactonization conditions a novel iodoetherification-hydroxylation process ensues which leads to 3-hydroxy-2,5-disubstituted tetrahydrofurans of which (182) is an example. These products were essentially single diastereoisomers according to all their spectroscopic data indicating that a well defined transition state must be involved in these cyclizations. Extensive work was then conducted in probing the mechanism of this reaction which required developing several complementary routes to various homoallylic alcohol precursors. Indeed, results thus generated suggest that the more expected iodotetrahydrofuran (183) is not an intermediate and neither is the plausible epoxide (201). A strong link with hydroxytetrahydrofuran formation and the amount of water present in the reaction was established. That the ester group plays a key role in the cyclization was evident from the observation that its repositioning (135) or removal (137) gave only iodo-diols (204-5 and 221-2) which failed to cyclize further. Similar cyclizations of the corresponding E-isomers gave iodotetrahydrofurans (199) in excellent yield. In each case, the cyclization was reasonably stereoselective with a modest improvement in yields being obtained in anhydrous solvents. However, under a variety of conditions, these did not lead to hydroxytetrahydrofurans. lodoetherification of simpler Z - and E-3-hydroxy-5-alkenes proceeded efficiently with high levels of stereoselection by a 5-endo-trig process and gave iodotetrahydrofurans, but only when anhydrous acetonitrile was used as solvent. The E-alk-5-en-ols gave a stereoselective reaction and the Z-isomers showed poorer selectivity. In semi-aqueous conditions iodo-diols and not hydroxytetrahydrofurans were obtained. Displacements on the iodotetrahydrofurans with azide (240) and hydroxide (243) equivalents have also been demonstrated in which the inverted products are obtained in good yield as single isomers. The relevance of all these tetrahydrofurans in Natural Product assembly is then emphasized by a few specific examples.

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Slater, Jonathan. "Cyclometallated nitrogen heterocycles - metallomesogens". Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269196.

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Yow, Shu Hui. "Claisen rearrangements of heterocycles". Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9491.

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This thesis is divided into five chapters. Chapter 1 is a review of de-aromatisation processes achieved by sigmatropic rearrangement. It covers the two main types of sigmatropic rearrangements, namely [2,3]- and [3,3]-rearrangement. Chapter 2 introduces the decarboxylative Claisen rearrangement (dCr) reaction and the aim to investigate its viability on more elaborate heterocyclic substrates is discussed. Research efforts into the synthesis of 3-sulfonyl-6-alkenyl-1,4-dioxan-2-ones are detailed. Chapter 3 discusses the extension of this methodology towards N-alkylmorpholinones. The first section examines 5,6-divinyl cis-morpholinones and L-alanine-derived trans-morpholinones as Claisen precursors, whereby stereospecific Ireland–Claisen rearrangement of L-alanine-derived trans-morpholinones was achieved. The second section details the synthesis of a novel L-proline-derived bicyclic morpholinone. However, attempted rearrangement led to degradation of product instead. The third section details the synthesis of 6-thienyl and 6-furanyl morpholinones, along with attempted Ireland–Claisen rearrangements and dCr reactions. Chapter 4 describes research efforts into the de-aromatising sigmatropic rearrangement of azide- and phthalimide-containing thienyl acyclic precursors. dCr Reaction of a cyanoacetate-containing substrate followed by unprecedented cyclisation led to the formation a highly-conjugated tetracycle and the mechanism of its formation is discussed. Chapter 5 provides experimental procedures and characterisation data.

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Hollis, Stephen James. "Heterocycles in peptide chemistry". Thesis, Open University, 2000. http://oro.open.ac.uk/54180/.

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The synthesis of 5-membered heterocyclic rings that bear both amine and carboxylic acid functional groups has been investigated using a 1,3-dipolar cycloaddition reaction strategy. These molecules, on incorporation into a chain of amino acids, have the potential to restrict the conformational freedom of the peptide. Cycloaddition of a nitrile oxide, derived from a Boc-protected naturally-occurring a-amino acid, with a pyrrolidine en amine led to a Boc-protected 3-aminoalkylisoxazole amino acid ester. The nitrogen and carbon termini of this isoxazole were coupled to other a-amino acids. Analysis of the dipeptide from coupling to (S)-alanine indicated that the integrity of the chiral centre of the isoxazole had been retained during the synthesis. Molecular modelling of a tripeptide unit incorporating the isoxazole showed that the presence of the ring had, as intended, restricted the conformational freedom of the molecule. Analogous cycloadditions using azomethine imines as the dipole yielded the corresponding tetrahydropyrazoles (pyrazolidines). These dipoles were generated by reaction of an aldehyde with a 1,2-disubstituted hydrazine, followed by elimination of the elements of water from the resulting aminol. Reaction with a dipolarophile bearing an electron withdrawing substituent gave predominantly the 4-substituted pyrazolidine. A study of the scope of the reaction found that, although the required carboxylic acid group could easily be incorporated by use of methyl acrylate as the dipolarophile, it proved impossible to attach an amine group to the ring using this methodology. However, by using one of the nitrogen atoms in the ring as the N-terminus, two pyrazolidines with protected amine and carboxylic acid groups were prepared, and these can be thought of as conformationally restricted B-amino acids.

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Waterfield, P. C. "Novel C-organostannyl heterocycles". Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384138.

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Esteves, Carlos Henrique Alves. "Palladium-catalysed enolate arylation in the synthesis of aromatic heterocycles and substituted heterocycles". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:b69e1a46-3275-4d77-a043-7207e7c93d59.

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Chapter 1. Introduction A literature background on the early development of the Pd-catalysed cross-coupling reactions and the later discovery of the enolate arylation reaction is presented. In the second part, the literature on pyruvate chemistry is explored, focusing on enantioselective transformations and the synthesis of α-arylated pyruvate derivatives. The final part presents reported protocols on the synthesis of β-carboline, isoquinoline and indole esters, from the classical approaches to the more recent methodologies based on metal catalysed transformations. Chapter 2. Results and Discussion 2.1 A study towards the synthesis of substituted amino-pyridines via 6π-electrocyclisation of 1-azatrienes is presented. The aspects impacting the efficiency of the cyclisation reaction are discussed using the experimental data collected and kinetic experiments published by other groups. 2.2 A synthetic methodology for the synthesis of substituted β-carbolines from 3-bromoindoles and commercially available ketones via Pd-catalysed enolate arylation is discussed. The α-functionalisation of the keto-indole intermediate with electrophiles provided access to C4-functionalised β-carbolines. The one-pot protocol for this sequence was also developed. 2.3 A protected pyruvate equivalent that allows the α-arylation and α-arylation/alkylation reactions to be carried out at the methyl group via Pd-catalysed enolate arylation is presented. The deprotection of the OBO moiety allows the formation mono and multiply α-functionalised pyruvates. 2.4 The synthesis of isoquinoline, β-carboline and indole esters via Pd-catalysed enolate arylation of the OBO-protected pyruvate equivalent developed in this thesis is demonstrated. The functionalisation of these heterocycles via α-alkylation of the aryl-ketone intermediates is also discussed and some examples synthesised to validate the methodology.

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Libri sul tema "Heterocycles"

Ameta, Keshav Lalit, Ravi Kant, Andrea Penoni, Angelo Maspero e Luca Scapinello, a cura di. N-Heterocycles. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-0832-3.

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Iskra, Jernej, a cura di. Halogenated Heterocycles. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-25103-0.

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Gakh, Andrei A., e Kenneth L. Kirk, a cura di. Fluorinated Heterocycles. Washington, DC: American Chemical Society, 2009. http://dx.doi.org/10.1021/bk-2009-1003.

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Gakh, Andrei A. Fluorinated heterocycles. A cura di American Chemical Society. Division of Fluorine Chemistry e American Chemical Society Meeting. Washington, DC: American Chemical Society, 2009.

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Eguchi, Shoji. Bioactive heterocycles. A cura di Eguchi Shoji. Berlin: Springer, 2006.

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Ameta, Keshav Lalit, a cura di. S-Heterocycles. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-4308-7.

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Motohashi, Noboru, a cura di. Bioactive Heterocycles VI. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-79218-5.

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Khan, Mahmud Tareq Hassan, a cura di. Bioactive Heterocycles III. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-73402-4.

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Khan, Mahmud Tareq Hassan, a cura di. Bioactive Heterocycles IV. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-73404-8.

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Khan, Mahmud Tareq Hassan, a cura di. Bioactive Heterocycles V. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-73406-2.

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Capitoli di libri sul tema "Heterocycles"

Vollhardt, Peter, e Neil Schore. "Heterocycles". In Organic Chemistry, 1934–2012. New York: Macmillan Learning, 2014. http://dx.doi.org/10.1007/978-1-319-19197-9_25.

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Mathey, François. "Phosphorus Heterocycles". In Modern Heterocyclic Chemistry, 2071–116. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527637737.ch23.

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Gakh, Andrei A. "Monofluorinated Heterocycles". In Topics in Heterocyclic Chemistry, 33–63. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/7081_2011_58.

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Iaroshenko, Viktor, e Satenik Mkrtchyan. "Phosphorus Heterocycles". In Organophosphorus Chemistry, 295–456. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2019. http://dx.doi.org/10.1002/9783527672240.ch8.

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Wang, Qian, e Jieping Zhu. "Other Heterocycles". In Stereoselective Multiple Bond-Forming Transformations in Organic Synthesis, 87–114. Hoboken, NJ, USA: John Wiley & Sons, Inc, 2015. http://dx.doi.org/10.1002/9781119006220.ch4.

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Gupta, Radha Raman, Mahendra Kumar e Vandana Gupta. "Aromatic Heterocycles". In Heterocyclic Chemistry, 39–104. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72276-9_3.

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Gupta, Radha Raman, Mahendra Kumar e Vandana Gupta. "Nonaromatic Heterocycles". In Heterocyclic Chemistry, 105–57. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72276-9_4.

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Gakh, Andrei A., e Kenneth L. Kirk. "Fluorinated Heterocycles". In ACS Symposium Series, 3–20. Washington, DC: American Chemical Society, 2009. http://dx.doi.org/10.1021/bk-2009-1003.ch001.

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Cenini, Sergio, e Fabio Ragaini. "Synthesis of Heterocycles". In Catalytic Reductive Carbonylation of Organic Nitro Compounds, 177–246. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-017-0986-6_5.

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Gupta, Radha Raman, Mahendra Kumar e Vandana Gupta. "Meso-Ionic Heterocycles". In Heterocyclic Chemistry, 579–626. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-662-07757-3_6.

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Atti di convegni sul tema "Heterocycles"

Mangalagiu, Violeta, Dumitrela Diaconu, Costel Moldoveanu, Gheorghita Zbancioc, Ramona Danac, Dorina Amariucai-Mantu, Vasilichia Antoci e Ionel Mangalagiu. "Hybrid and chimeric nitrogen heterocycles with biological activity". In Scientific seminar with international participation "New frontiers in natural product chemistry". Institute of Chemistry, Republic of Moldova, 2023. http://dx.doi.org/10.19261/nfnpc.2023.ab01.

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Abstract (sommario):

Nitrogen heterocycles, especially azine and azole derivatives, are highly valuable scaffolds in medicinal chemistry, being the core components of a large variety of drugs with variously biological activity such as antiplasmodial and antimalarial, antitubercular, antibacterial, antifungal, anticancer, analgesic, antidepressant, anxiolytics, antihypertensive, anticoagulants, diuretics, etc. As a result, obtaining of such entities continues to arouse a strong interest from academia and industry. As part of our ongoing research in the area of nitrogen heterocyclic derivatives, we present herein some representative results obtained by our group in the field of hybrid and chimeric azahetrocycles compounds with antimicrobial and anticancer activity. Chemistry, anticancer, antibacterial, antifungal and antituberculosis activity of compounds is presented. Some of the hybrid and chimeric structures possess a good anticancer and/or antimicrobial activity.

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Haaland, Peter, e James Targove. "Flowing Afterglow Synthesis of Polythiophene Films". In Nonlinear Guided-Wave Phenomena. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/nlgwp.1991.tue4.

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Polymers of aromatic heterocycles such as thiophene and pyrrole have been actively investigated for their promising electrical and optical characteristics. However the use of these materials in waveguide structures has been constrained by morphological and synthetic barriers. Specifically, larger oligomers are less soluble causing multiphase chemical kinetics and irregular morphology in the metal-catalyzed coupling syntheses.fi] Electrochemical preparation methods also produce grainy or fibrillar material, most probably because the heterogeneous boundary conditions on film growth change as insulating or semi-conducting material is deposited on the electrodes. [2] We report here a synthetic approach to the polymeric heterocycle polythiophene using electronically excited argon metastables to activate organic precursors. This method is seen to produce dense, uniform films with desirable thiophene linkages and excellent optical properties.

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Stadlbaur, Wolfgang, Gerhard Hojas e Werner Fiala. "Thermal Cyclization of 2-Hydrazonoacyl-3-oxo-heterocycles to Pyrazolo[4,3-c]fused Heterocycles". In The 2nd International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 1998. http://dx.doi.org/10.3390/ecsoc-2-01669.

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Gutierrez, Margarita, Yorley Duarte, Barbara Arevalo, Gonzalo Martinez, Francisca Matus, Tomas Poblete, Jessica Amigo, Gabriel Vallejos e Luis Astudillo. "NITROGEN HETEROCYCLES AS POTENTIAL ANTIBACTERIAL AGENTS". In The 17th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2013. http://dx.doi.org/10.3390/ecsoc-17-a035.

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Карасева, И. Н., М. О. Карасев e С. В. Курбатова. "IDENTIFICATION OF THE COMPONENTS OF COMPLEX MIXTURES OF NITROGENIC HETEROCYCLES". In Инновации и «зелёные» технологии : IV Всероссийская научно-практическая конференция. Crossref, 2024. http://dx.doi.org/10.34830/sounb-conf.2023.64.97.017.

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В статье рассмотрены вопросы, связанные с исследованием производных азотистых гетероциклов в условиях обращенно-фазового варианта высокоэффективной жидкостной хроматографии. Определены сорбционные и физико-химические характеристики некоторых производных азолов. Предложено использование спектрального подхода для групповой идентификации компонентов сложных смесей азотистых гетероциклов и корреляций между удерживанием и физико-химическими параметрами для индивидуальной идентификации. The article deals with issues related to the study of nitrogenous heterocycles derivatives under conditions of a reversed-phase high-performance liquid chromatography. The sorption and physicochemical characteristics of some azole derivatives have been determined. The use of a spectral approach for group identification of nitrogenous heterocycles complex mixtures components and correlations between retention and physicochemical parameters for individual identification is proposed.

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Babaev, E. V. "Polarity rules in computer design of heterocycles". In The first European conference on computational chemistry (E.C.C.C.1). AIP, 1995. http://dx.doi.org/10.1063/1.47874.

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Padwa, Albert. "Synthesis of Heterocycles Using Tandem Cyclization Processes." In The 3rd International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 1999. http://dx.doi.org/10.3390/ecsoc-3-01730.

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Mongin, Florence, William Erb e Frédéric Lassagne. "Aromatic Iodides: Synthesis and Conversion to Heterocycles". In International Electronic Conference on Synthetic Organic Chemistry. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/ecsoc-26-13641.

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"Investigating the Biological Activity of Some Useful Heterocycles". In Nov. 27-28, 2017 South Africa. EARES, 2017. http://dx.doi.org/10.17758/eares.eap517215.

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Tabolin, Andrey, Vladimir Motornov, Valentine Nenajdenko e Sema Ioffeа. "α-FLUORONITROALKENES IN THE SYNTHESIS OF FLUORINATED HETEROCYCLES". In Chemistry of nitro compounds and related nitrogen-oxygen systems. LLC MAKS Press, 2019. http://dx.doi.org/10.29003/m735.aks-2019/123-125.

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Rapporti di organizzazioni sul tema "Heterocycles"

Boyer, Joseph H. Heterocycles as Laser Dyes. Fort Belvoir, VA: Defense Technical Information Center, giugno 1992. http://dx.doi.org/10.21236/ada251574.

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Habben, C., L. Komorowski, W. Maringgele, A. Meller e K. Niedenzu. Reactions of Some Boron Heterocycles with Pyrazole. Fort Belvoir, VA: Defense Technical Information Center, marzo 1989. http://dx.doi.org/10.21236/ada205979.

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Darke, Greg, Tommy Hawkins, Adam Brand, Milton Mckay e Ismail Ismail. Energetic, Low Melting Salts of Simple Heterocycles. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2003. http://dx.doi.org/10.21236/ada410888.

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Huang, Qinhua. New Palladium-Catalyzed Approaches to Heterocycles and Carbocycles. Office of Scientific and Technical Information (OSTI), dicembre 2004. http://dx.doi.org/10.2172/835382.

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Beasley, Jonathan. Synthesis of heterocycles: Indolo (2,1-a) isoquinolines, renewables, and aptamer ligands for cellular imaging. Office of Scientific and Technical Information (OSTI), gennaio 2013. http://dx.doi.org/10.2172/1082980.

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Paciorek, K. L., J. H. Nakahara e R. H. Kratzer. Heterocycles Based on Group 3, 4, and 5 Elements Precursors for Novel Glasses and Ceramics. Fort Belvoir, VA: Defense Technical Information Center, maggio 1988. http://dx.doi.org/10.21236/ada205586.

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Lineberger, William C., e Veronica M. Bierbaum. Thermochemistry and Dynamics of Reactive Species: Nitrogen-Rich Substituted Heterocycles and Anionic Components of Ionic Liquids. Fort Belvoir, VA: Defense Technical Information Center, febbraio 2009. http://dx.doi.org/10.21236/ada495370.

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Adams, Richard D. Studies of the Transformations of Sulfur Containing Heterocycles by Transition Metal Cluster Compounds. Final Report, June 1, 1995 - October 31, 1999. Office of Scientific and Technical Information (OSTI), maggio 2001. http://dx.doi.org/10.2172/803362.

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Liu, Shih-Yuan. Hydrogen Storage by Novel CBN Heterocycle Materials. Office of Scientific and Technical Information (OSTI), ottobre 2015. http://dx.doi.org/10.2172/1221989.

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Savage, Paul B., John M. Desper e Samuel H. Gellman. Stereoselective Oxidation of an Eleven-Membered Heterocycle. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1992. http://dx.doi.org/10.21236/ada252091.

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