Готові списки джерел за темами / Olefin reactions

Добірка наукової літератури з теми "Olefin reactions"

Автор: Grafiati
Опубліковано: 10 грудня 2022
Оновлено: 28 січня 2023

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Статті в журналах з теми "Olefin reactions"

1

Liu, Qiang, Xufang Liu, and Bin Li. "Base-Metal-Catalyzed Olefin Isomerization Reactions." Synthesis 51, no. 06 (February 19, 2019): 1293–310. http://dx.doi.org/10.1055/s-0037-1612014.

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Анотація:
The catalytic olefin isomerization reaction is a highly efficient and atom-economic transformation in organic synthesis that has attracted tremendous attention both in academia and industry. Recently, the development of Earth-abundant metal catalysts has received growing interest owing to their wide availability, sustainability, and ­environmentally benign nature, as well as the unique properties of non-precious metals. This review provides an overview of a broad range of base-metal-catalyzed olefin isomerization reactions categorized ­according to their different reaction mechanisms.1 Introduction2 Base-Metal-Catalyzed Olefin Isomerization Reactions3 Base-Metal-Catalyzed Cycloisomerization Reactions4 Conclusion
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2

Chow, Yuan L., and Xianen Cheng. "The dual pathway in photocycloaddition of 1,3-diketonatoboron difluorides: excimer reactions." Canadian Journal of Chemistry 69, no. 10 (October 1, 1991): 1575–83. http://dx.doi.org/10.1139/v91-232.

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Анотація:
The lowest singlet excited state of dibenzoylmethanatoboron difluoride DBMBF2, a model compound of the BF2 complexes of 1,3-diketones, reacted with various simple olefins to give regiospecific and stereospecific photocycloadducts of 1,5-diketones similar to those from the de Mayo type reaction. DBMBF2 in acetonitrile exhibited two discrete fluorescences at 398 and 416 nm for the monomer and at 522 nm for the excimer; they were both quenched, but in different proportions, by a simple olefin. An "oxygen test" showed that the excimer of DBMBF2 is formed irreversibly in acetonitrile. The quantum yields of the photocycloaddition were shown to be proportional not only to olefin concentrations but also to DBMBF2 concentrations. Kinetic analysis has established that the total quantum yield is the sum of those arising from the interactions of the singlet excited DBMBF2 and its excimer, respectively, with an olefin, i.e., the sum of the quantum yields of exciplex and triplex pathways. The contributions from the two pathways are determined by the type of olefins and the range of DBMBF2 concentrations. For endocyclic olefins, the triplex pathway is more important and the corresponding photocycloaddition becomes very efficient as soon as the excimer starts to form in [DBMBF2] > 0.001 M. For the monosubstituted olefins, on the contrary, the exciplex pathway is always more important than the triplex pathway; they react primarily from the singlet excited state of DBMBF2. Key words: singlet state photocycloaddition, irreversible excimer formation, excimer cycloaddition, triplex and exciplex reactions.
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3

Vosloo, H. C. M., and J. A. K. Du Plessis. "A review of the mechanisms of the olefin metathesis reaction." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 7, no. 4 (March 17, 1988): 154–61. http://dx.doi.org/10.4102/satnt.v7i4.921.

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Анотація:
During the olefin metathesis reaction carbon-carbon double bonds are broken and rearranged to give a redistribution of alkilydene groups. A review of the different mechanistic approaches is given under the headings: The pairwise mechanism; The metal carbene chain mechanism with reference to the formation of the carbene and metallacyclobutane intermediate; The reactions of the olefins; and The degradation of unsaturated polymers.
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4

Křeček, Václav, Jiří Protiva, Miloš Buděšínský, Eva Klinotová, and Alois Vystrčil. "Preparation of C(18)-empiric 20,29,30-trinorlupane derivatives. 1H, 13C NMR and mass spectra." Collection of Czechoslovak Chemical Communications 51, no. 3 (1986): 621–35. http://dx.doi.org/10.1135/cccc19860621.

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Анотація:
Reaction of amide I with nitrous acid gave the olefins II, III and IV. On allylic oxidation of olefin IV α,β-unsaturated ketone V is formed from which olefins VIII and IX were prepared by a sequence of further reactions. Addition of hydrogen to the double bond of olefin IV and α,β-unsaturated ketone V takes place on catalytic hydrogenation from the β-side and leads to derivatives with cis-annellated rings D/E. This made the preparation of hydrocarbons VI and VII epimeric on C(18) possible, which represent reference compounds for the study of the effect of substituents on the chemical shifts of the methyl groups and the saturated carbon atoms of 18αH and 18βH-lupane derivatives. The configuration of the hydroxyl group in epimers XI and XII were derived from 1H NMR spectra. Deuteration of olefins III, IV and IX gave deuteriohydrocarbons XVI to XVIII. The 1H, 13C NMR and mass spectra of the substances prepared are discussed.
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5

Silva, Thiago S., and Fernando Coelho. "Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances." Beilstein Journal of Organic Chemistry 17 (July 7, 2021): 1565–90. http://dx.doi.org/10.3762/bjoc.17.112.

Повний текст джерела
Анотація:
Olefin double-bond functionalization has been established as an excellent strategy for the construction of elaborate molecules. In particular, the hydroalkylation of olefins represents a straightforward strategy for the synthesis of new C(sp3)–C(sp3) bonds, with concomitant formation of challenging quaternary carbon centers. In the last 20 years, numerous hydroalkylation methodologies have emerged that have explored the diverse reactivity patterns of the olefin double bond. This review presents examples of olefins acting as electrophilic partners when coordinated with electrophilic transition-metal complexes or, in more recent approaches, when used as precursors of nucleophilic radical species in metal hydride hydrogen atom transfer reactions. This unique reactivity, combined with the wide availability of olefins as starting materials and the success reported in the construction of all-carbon C(sp3) quaternary centers, makes hydroalkylation reactions an ideal platform for the synthesis of molecules with increased molecular complexity.
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6

Plessow, Philipp N., and Felix Studt. "Olefin methylation and cracking reactions in H-SSZ-13 investigated with ab initio and DFT calculations." Catalysis Science & Technology 8, no. 17 (2018): 4420–29. http://dx.doi.org/10.1039/c8cy01194j.

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Анотація:
The olefin cycle of the methanol-to-olefins process is investigated for the zeolite H-SSZ-13 using periodic, van-der-Waals corrected DFT calculations, together with MP2 corrections derived from cluster models, which are essential for accurate barriers.
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7

Groso, Emilia, and Corinna Schindler. "Recent Advances in the Application of Ring-Closing Metathesis for the Synthesis of Unsaturated Nitrogen Heterocycles." Synthesis 51, no. 05 (February 8, 2019): 1100–1114. http://dx.doi.org/10.1055/s-0037-1611651.

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Анотація:
This short review summarizes recent advances relating to the application of ring-closing olefin-olefin and carbonyl-olefin metathesis reactions towards the synthesis of unsaturated five- and six-membered nitrogen heterocycles. These developments include catalyst modifications and reaction designs that will enable access to more complex nitrogen heterocycles.1 Introduction2 Expansion of Ring-Closing Metathesis Methods3 Evaluation of Catalyst Design4 Indenylidene Catalysts5 Unsymmetrical N-Heterocyclic Carbene Ligands6 Carbonyl-Olefin Metathesis7 Conclusions
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8

Cory, Robert M., Paul C. Anderson, Murray D. Bailey, Fred R. McLaren, Richard M. Renneboog, and Brian R. Yamamoto. "Nitro-olefin bicycloannulation: one-step synthesis of tricyclo[3.2.1.02,7]octan-6-ones from cyclohexenones and of tricyclo[2.2.1.02,6]heptan-3-ones from cyclopentenones." Canadian Journal of Chemistry 63, no. 10 (October 1, 1985): 2618–27. http://dx.doi.org/10.1139/v85-435.

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Анотація:
Nitro-olefins bicycloannulate the α′-enolates of α-cyclohexenones and α-cyclopentenones by initial addition at −78 °C, followed by further reaction insitu in the presence of hexamethylphosphoramide in refluxing tetrahydrofuran to give tricyclo[3.2.1.02,7]octan-6-ones and tricyclo[2.2.1.02,6]heptan-3-ones in a single synthetic step. The reactions with 1-nitropropene and with a nitro-olefin having a more complex β-substituent are stereoselective, forming predominantly the tricyclic diastereomer in which the group derived from the β-substituent of the nitro-olefin is syn to the carbonyl bridge. Based on the isolation of intermediates and side products, the mechanism of the bicycloannulation is shown to proceed via sequential kinetically controlled conjugate addition of the enolate to the nitro-olefin at low temperatures, thermodynamically controlled intramolecular Michael addition at higher temperatures to give a bicyclo[2.2.2]octanone intermediate, and hexamethylphosphoramide-assisted expulsion of the nitro group as nitrite ion with formation of the cyclopropane ring. For the first time this type of bicycloannulation has been applied to cyclopentenones, and a one-step synthesis of tricyclenone has been carried out to demonstrate the synthetic utility of this new reaction.
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9

Riehl, Paul S., Daniel J. Nasrallah, and Corinna S. Schindler. "Catalytic, transannular carbonyl-olefin metathesis reactions." Chemical Science 10, no. 44 (2019): 10267–74. http://dx.doi.org/10.1039/c9sc03716k.

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Анотація:
Transannular carbonyl-olefin metathesis reactions complement existing procedures for related ring-closing, ring-opening, and intermolecular carbonyl-olefin metathesis. This enables molecular editing of steroid-derived frameworks.
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10

Remete, Attila Márió, Tamás T. Novák, Melinda Nonn, Matti Haukka, Ferenc Fülöp, and Loránd Kiss. "Synthesis of novel fluorinated building blocks via halofluorination and related reactions." Beilstein Journal of Organic Chemistry 16 (October 16, 2020): 2562–75. http://dx.doi.org/10.3762/bjoc.16.208.

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Анотація:
A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.
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Більше джерел

Дисертації з теми "Olefin reactions"

1

Burger, Barbara J. Bercaw John E. "Olefin insertion and [beta]-elimination reactions of permethylniobocene olefin hydride and permethylscandocene alkyl complexes /." Diss., Pasadena, Calif. : California Institute of Technology, 1987. http://resolver.caltech.edu/CaltechETD:etd-01162008-111854.

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2

Yu, Miao. "Stereoselective Olefin Metathesis Reactions for Natural Product Synthesis." Thesis, Boston College, 2014. http://hdl.handle.net/2345/3861.

Повний текст джерела
Анотація:
Thesis advisor: Amir H. Hoveyda
Chapter 1. The first examples of highly Z- and enantioselective ring-opening/cross-metathesis reactions are disclosed. Transformations involve meso cyclic olefin substrate and styrenes or enol ethers as olefin cross partners. A stereogenic-at-Mo monoaryloxide monopyrrolide (MAP) complex, prepared and used in situ, is discovered for the efficient formation of Z olefins. Such complex, bearing a relatively smaller adamantylimido and a larger chiral aryloxide ligand, leads to kinetic Z-selectivity due to the size differential. In most cases, the resulting disubstituted Z olefins are formed with excellent stereoselectivity (>95% Z). Chapter 2. The protocols for efficient Z-selective formation of macrocyclic disubstituted alkenes through catalytic ring-closing metathesis (RCM) is described. Stereoselective cyclizations are performed with either Mo- or W-based monoaryloxide monopyrrolide (MAP) complex at 22 oC. Synthetic utility of such broadly applicable transformation is demonstrated by synthesis of several macrocyclic natural products: relatively simpler molecules such as epilachnene (91% Z) and ambrettolide (91% Z), as well as advanced precursors to epothilones C and A (97% Z) and nakadomarin A (94% Z). Several principles of catalytic stereoselective olefin metathesis reactions are summarized based on the studies: 1) Mo-based catalysts are capable of delivering high activity but can be more prone to post-RCM isomerization. 2) W-based catalysts, though furnish lower activity, are less likely to cause the loss of kinetic Z selectivity by isomerization. 3) Reaction time is critical for retaining the stereoselectivity gained from kinetic, which not only applicable with MAP complexes but potentially with other complexes as well. 4) By using W-based catalyst, polycyclic alkenes can be accessed with sequential RCM reactions, without significant erosion of the existing Z olefins in the molecule. Chapter 3. An enantioselective total synthesis of anti-proliferative agent (+)-neopeltolide is presented. The total synthesis is accomplished in 11 steps for the longest linear sequence and 28 steps in total, including 8 catalytic reactions. Particularly, several Mo- or Ru-catalyzed stereoselective olefin metathesis reactions as well as N-hetereocyclic carbene (NHC)-catalyzed enantioselective boron conjugate addition to an acyclic enoate have proven to be effective for convergent construction of the molecule. The most important novelty of the study incorporates the explorations of feasibility of Z-selective cross-metathesis reactions to solve the challenge of installing two Z olefins with excellent selectivity
Thesis (PhD) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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3

Sinha, Amritanshu. "Synthesis of molybdenum olefin metatheses catalysts through protonation reactions." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36262.

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Анотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006.
Vita.
Includes bibliographical references.
The attempted syntheses of molybdenum imido alkylidene complexes of the type Mo(NArc,)(CH-t-Bu)[Biphen] and Mo(N-2-CF3C6H4)(CHCMe2Ph)[Biphen] (Biphen2 = 3,3'-di-t-butyl-5,5',6,6'-tetramethyl- 1,1'-biphenyl-2,2'-diolate) from Mo(NArcl)(CH-t-Bu)(OTf)2(dme) and [Biphen]K2 have sporadically afforded mixtures containing the desired products along with the corresponding amido alkylidyne complexes, Mo(NHArcl)(C-t-Bu)[Biphen] and Mo(NH-2-CF3C6H4)(CCMe2Ph)[Biphen], respectively. The reaction of [Biphen]K2 with Mo(NArc,)(CH-t-Bu)(OTf)2(dme) and 10 equivalents of triethylamine reproducibly gave Mo(NHArc,)(C-t-Bu)[Biphen] in 40% yield. An X-ray crystal structure of a related complex, Mo(NHArc,)(CCMe2Ph)[S-Biphen] confirmed the proposed structure and also revealed that one ortho chloride approaches within 2.93 A of the metal approximately trans to the alkylidyne ligand. Attempts to prepare three other amido alkylidyne complexes in an analogous manner from Mo(NR")(CH-t-Bu)(OTf)2(dme) (NR" = N-2-CF3C6H4, N-2,6-i-Pr2C6H5, N-2,6-Me2C6H5) with [Biphen]K2 in the presence of 10-20 equivalents of triethylamine failed.
(cont.) Chapter 2 The reaction between Mo(NAr)(CH-t-Bu)(CH2-t-Bu)2 (Ar = 2,6-i-Pr2C6H3) and various alcohols (1-AdamantylOH, t-BuOH, ArOH, (CF3)2CHOH, (CF3)2MeCOH, (CF3)3COH, C6F5OH) in pentane or toluene yielded either complexes of the type Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) through direct addition of ROH across a Mo-C bond, or complexes of the type Mo(NAr)(CH2-t-Bu)3(OR) through direct addition of ROH across a Mo=C bond. The trineopentyl species appear to be formed when the alcohol has a relatively low pKa. The outcome also can depend upon whether the alcohol is employed neat, or in benzene, and mixtures are observed in some circumstances. The conversion of Mo(NAr)(CH2-t-Bu)3(OR) into Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) was shown to be unimolecular in several examples. Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OR) complexes have been found to be surprisingly active catalysts for various metathesis reactions. In contrast, M(NAr)(CH-t-Bu)(CH2-t-Bu)2 species are virtually inactive for metathesis. X-ray structures are reported for Mo(NAr)(CH2-t-Bu)3(OC6F5), Mo(NAr)(CH-t-Bu)(CH2-t-Bu)IOSi(O-t-Bu)3], [Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F)12, and Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5)(PMe3).
(cont.) Chapter 3. Complexes of the type Mo(NR")(CHR')(N(R)3,5-C6H3Me2)2 (NR" = N-2,6-i-Pr2C6H, N-2,6-Me2C6Hs; R' = t-Bu, CMe2Ph; R' = i-Pr, t-Bu) and Mo(NR")(CHR')(NR2)2 (NR" = N-2,6-i-Pr2C6H,, N-2,6-Me2C6H5; R' = t-Bu, CMe2Ph; R = Me, Ph) can be isolated as orange-red solids in 30-35% yields or oils by reacting Mo(NR")(CHR')(OTf)2(dme) with LiN(R')(3,5-C6H3Me2)(ether) or with LiNR2. The synthesis of Mo(NR")(CHCMe2Ph)(NPh2)2 can be improved to 70-90% isolated yields when Mo(NR")(CHCMe2Ph)[OCMe(CF3)212 is used with LiNPh2(ether). Mo(NAr)(CHCMe2Ph)(NPh2)2 has been crystallographically characterized. Mo(NR")(CHR')(N(R)3,5-C6H3Me2)2 species reacted with t-BuOH and Me(CF3)2COH in benzene to give Mo(NR")(CHR')(OR)2 (OR = O-t-Bu, OCMe(CF3)2) in situ. However, no reactions of Mo(NR")(CHR')(N(R')3,5-C6H3Me2)2 were observed with enantiomerically pure diols such as [R-TRIP]H2 (3,3'-2,4,6-i-Pr3C6H2-binaphthol), [R-Ph]H2 (3,3'-C6H5-binaphthol), [rac-Mesitylbinap]H2 (3,3'-2,4,6-Me3C6H2-binaphthol) and [R-TMSbinapJH2 (3,3'-SiMe3-binaphthol).
(cont.) Bisamido complexes of the type Mo(NR")(CHR')(NPh2)2 were found to react with the aforementioned alcohols and diols to give Mo(NR")(CHR')(diolate) species in situ, which were further reacted in a catalytic fashion with two substrates to give the corresponding ring-closed products. Preliminary :results of the in situ catalysis demonstrated here compare fairly well with the analogous catalytic reactions reported with isolated catalysts. Appendix A. Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5) (Ar = 2,6-i-Pr2C6H3) can be reacted with 5-10 equivalents of trans-3-hexene to give a crystallographically characterized dimeric complex, [Mo(NAr)(CH2-t-Bu)(OC6F5)]2 that contains an unbridged Mo=Mo bond (2.410(8) A) in high yields. The above complex can also be prepared by treating Mo(NAr)(CH-t-Bu)(CH2-t-Bu)(OC6F5) with 0.5 equivalents of divinylbenzene. IMo(NAr)(CH2-t-Bu)(OC6F5)]2 will slowly catalyze the metathesis reactions of simple substrates, although less than 5% of the catalyst seems to be activated in such reactions.
(cont.) It was observed that catalytically active species for metathesis reactions can be generated by another Mo (d2) species, Mo(NArcl)(Biphen)(H2C=CH2)(ether) (NArc, = N-2,6-C12C6H3, Biphen2 = 3,3'-di-t-butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'-diolate) that could effect the ring-opening metathesis polymerization of norbornene. A mixture of Mo(NArcl)(Biphen)(H2C=CH2)(ether) and 20 equivalents of diallylether in benzene-d6 when treated with 10 equivalents of norbornene gives 54% conversion to dihydrofuran in 10 days.
by Amritanshu Sinha.
Ph.D.
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4

Bowen, Lucy Elizabeth. "New reactions and activation methods in olefin trimerisation catalysis." Thesis, University of Bristol, 2008. http://hdl.handle.net/1983/7eba4c9b-e466-4390-8d24-f14002376be8.

Повний текст джерела
Анотація:
This thesis describes new catalytic reactions, new activation methods and new ligand derivatives based on chromium lV,N-bis(diarylphosphino)amine (PNP) olefin trimerisation catalysts. Chapter 1 presents an introduction to this area. The main differences between non-selective olefin olig.omerisation and selective trimerisation are discussed, as well as the commercial uses of LAOs. The mechanism of trimerisation and a survey of successful catalyst systems is given, with particular emphasis on PNP ligands. More recent advances such as selective tetramerisation are discussed. Chapter 2 describes the use of chromium PNP catalysts for the cotrimerisation of ethene and other alkene monomers, particularly styrene. The effect of temperature, reaction time, comonomer concentration and ligand structure are investigated and a mechanism scheme is proposed. The cotrimerisation .of ethene and styrene was found to form phenylhexene, with the ligand 1 system giving predominantly I-phenylhexene isomers 50 and 51, with a TOF of 2468 h-I. Other PNP ligands tested gave 3-phenylhexene isomers 55 and 56. The trimerisation of isoprene using the same chromium PNP systems is explored in Chapter 3. Using the ligand 1 system, the trimerisation of isoprene produced isomers of 2,6,11-trimethyldodecatetraene, 1,5,1 O-trimethyl-l ,5,9cyclododecatriene and higher isoprene oligomers, with a productivity of 826 g (g Cr hrl . Other PNP ligands tested produced the same products as ligand 1 with differing productivities. Some of the results from these two chapters have been published.93.130 Chapter 4 describes the use of chromium(I) PNP carbonyl complexes for the oligomerisation of ethene. The syntheses and structures of [Cr(CO)4(1)], [Cr(CO)4(19)], [Cr(CO)4(5)] and [Cr(CO)4(NO)(1)] are reported. These compounds were then tested for ethene trimerisation by activation with an oxidising agent with a weakly coordinating anion, [N(p-BrC6fu)3][B(C6Fs)4] and a CO scavenger, AlEt3. The results from this chapter have been published.16o A series of novel PNP and dppe based ligands with ortho oxygen donors on the phenyl rings were also synthesised and tested for ethene trimerisation, as described in Chapter 5. Finally Chapter 6 gives experimental details for the preceding chapters.
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5

van, Rooy Sara Emily. "Reactivity of rhodium-heteroatom bonds: from catalytic bond activation to new strategies for olefin functionalization." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/444.

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Анотація:
Rhodium complexes bearing multidentate nitrogen donor ligands were investigated for their ability to promote alkyne and olefin functionalization reactions. This thesis work is comprised of two projects in which rhodium-heteroatom reactivity is investigated: P-H bond activation reactions and olefin functionalizations via rhodaoxetane intermediates. [Tp*Rh(PPh3)2] [Tp* = hydrotris(3,5-dimethylpyrazolyl)borate] and [Tp*Rh(cod)]2 (cod = cyclooctadiene) were evaluated for their activity in alkyne hydrophosphinylation in comparison to known catalysts for this reaction. [Tp*Rh(PPh3)2]and [Tp*Rh(cod)]2 were both shown to effect hydrophosphinylation of 1-octyne with diphenylphosphine oxide with high regioselectivity but moderate yields in comparison with Wilkinson's catalyst [C1Rh(PPh3)3]. [Tp*Rh(PPh3)2] was further shown to effect hydrophosphinylation of a range of aromatic and aliphatic alkynes with diphenylphosphine oxide, in each case exclusively providing the E-linear vinylphosphineoxide product. 1H and 31P NMR spectroscopy provided evidence that alkyne hydrophosphinylation in the presence of pyrazolylborate rhodium complexes follows an analogous mechanism to that proposed for this reaction catalyzed by [C1Rh(PPh3)3] or[C1Rh(cod)]2. The 2-rhodaoxetane [(TPA)Rhmec2_,-4u, 0-2-oxyethypr BPh4- (TPA = tris[(2-pyridal)methyl]amine) was investigated for its potential as an intermediate in proposed functionalization reactions of olefins. RTPA)Rh111(K2-C,0-2-oxyethyl)]+ BPh4- was prepared by two published methods with limited success. A third method involved the use of nitrous oxide to oxygenate [(12-ethene)(K4-TPA)Rh1]+ to RTPA)Rh1110(-2-C,0-2-oxyethyDr. Only a trace amount of [(TPA)Rhmoc2 -C,0-2-oxyethypr was observed in the 1I-1 NMR spectrum of this reaction mixture. Initial test reactions of [(TPA)Rhilioc2_C,0-2-oxyethypr combined with substrates (aniline, toluenesulfonamide, phenylboronic acid, or benzaldehyde) were inconclusive since the results were obscured by the impurity of the samples.
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6

Pilyugina, Tatiana. "Molybdenum alkylidene complexes : syntheses and applications to olefin metathesis reactions." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40289.

Повний текст джерела
Анотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2007.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Vita.
Includes bibliographical references.
Chapter 1. Alkylimido Molybdenum Complexes: Synthesis, Characterization and Activity as Chiral Olefin Metathesis Catalysts. Molybdenum olefin metathesis catalysts that contain previously unexplored aliphatic 1- phenylcyclohexylimido (PhCyN) and 2-phenyl-2-adamantylimido (PhAdN) groups were prepared and shown to be efficient and selective in a variety of olefin metathesis reactions. Five catalysts, Mo(NR)(CHCMe2Ph)[(S)-Biphen], Mo(NR)(CHCMe2Ph)[(R)-Trip](THF) (R = 1- adamantyl, PhCy, PhAd; Biphen = 3,3'-di-tert-butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'- diolate; Trip = 3,3'-bis(2,4,6-triisopropylphenyl)- 1,1'-binaphthyl-2,2'-diolate) and Mo(NAd)(CHCMe2Ph)[(R)-Trip](THF) (Ad = I-adamantyl), were synthesized. Their catalytic activity and enantioselectivity in desymmetrization reactions such as ring-closing metathesis of amines and lactams and ring-opening/cross metathesis of a substituted norborneol with styrene were compared to the results obtained with the only known alkylimido catalyst, Mo(NAd)(CHCMe2Ph)[(S)-Biphen]. The new catalysts prove to be similar to Mo(NAd)(CHCMe2Ph)[(S)-Biphen] in the majority of the studied reactions, and the examined catalysts show overall improvement in activity and enantioselectivity compared to the traditional arylimido catalysts. Chapter 2. Synthesis of Molybdenum Imido Alkyl and Alkylidene Complexes from Molybdenum Imido Tetrachlorides. Several new Mo(NR)C14(THF) species (R = C6F5, 3,5-(CF3)2C6H3, Ad, CPh3, and 2,6-i- Pr2C6H3) were prepared via the treatment of MoC14(THF)2 with azides, and then alkylated with neopentyl reagents. Addition of Mo(NR)C14(THF) complexes in toluene to a cold solution of NpMgCl in ether gave Mo(NR)Np3Cl species (R = CFs5, 3,5-(CF3)2C6H3, Ad, Ph3C, and 2,6-i- Pr2C6H3 (Ar); Np = CH2-t-Bu) in poor (35 %) to modest (51 %) yields. Heating Mo(NAr)Np3C1 in C6D6 to 50 OC results in a-hydrogen abstraction to give neopentane and a molecule whose
(cont.) Chapter 2. Synthesis of Molybdenum Imido Alkyl and Alkylidene Complexes from Molybdenum Imido Tetrachlorides. Several new Mo(NR)C14(THF) species (R = C6F5, 3,5-(CF3)2C6H3, Ad, CPh3, and 2,6-i- Pr2C6H3) were prepared via the treatment of MoC14(THF)2 with azides, and then alkylated with neopentyl reagents. Addition of Mo(NR)C14(THF) complexes in toluene to a cold solution of NpMgCl in ether gave Mo(NR)Np3Cl species (R = CFs5, 3,5-(CF3)2C6H3, Ad, Ph3C, and 2,6-i- Pr2C6H3 (Ar); Np = CH2-t-Bu) in poor (35 %) to modest (51 %) yields. Heating Mo(NAr)Np3C1 in C6D6 to 50 OC results in a-hydrogen abstraction to give neopentane and a molecule whose NMR spectra are consistent with it being Mo(NAr)(CH-t-Bu)NpCl; it decomposed bimolecularly upon attempted isolation. The other Mo(NR)Np3Cl species were found to be more stable than Mo(NAr)Np3C1, but when they did decompose at elevated temperatures, no neopentylidene complex could be observed. Addition of neopentyllithium to Mo(NR)Np3CI species (R = Ar, CPh3, or Ad) yielded Mo(NR)(CH-t-Bu)Np2 species, the adamantylimido version of which is unstable toward bimolecular decomposition. Addition of I equivalent of 2,6-diisopropylphenol, 2,6-dimethylphenol, or 3,5-(2,4,6-i-Pr3C6H2)2C6H30H (HIPTOH) to Mo(NCPh3)(CH-t-Bu)Np2 led to formation of Mo(NCPh3)(CH-t-Bu)Np(OR) species, while treatment of Mo(NCPh3)(CH-t- Bu)Np2 with C6FsOH gave Mo(NCPh3)Np3(OC6Fs). The three monophenoxide neopentylidene complexes showed metathesis activity for ring-closing a small selection of amines and an ether. X-ray studies were completed for Mo[N-3,5-(CF3)2C6H3]C14(THF), Mo[N-3,5-(CF3)2C6H3]Np3CI, Mo(NCPh3)Np3CI, and Mo(NCPh3)(CH-t-Bu)Np(OHIPT).
(cont.) Addition of I equivalent of 2,6-diisopropylphenol, 2,6-dimethylphenol, or 3,5-(2,4,6-i-Pr3C6H2)2C6H30H (HIPTOH) to Mo(NCPh3)(CH-t-Bu)Np2 led to formation of Mo(NCPh3)(CH-t-Bu)Np(OR) species, while treatment of Mo(NCPh3)(CH-t- Bu)Np2 with C6FsOH gave Mo(NCPh3)Np3(OC6Fs). The three monophenoxide neopentylidene complexes showed metathesis activity for ring-closing a small selection of amines and an ether. X-ray studies were completed for Mo[N-3,5-(CF3)2C6H3]C14(THF), Mo[N-3,5-(CF3)2C6H3]Np3CI, Mo(NCPh3)Np3CI, and Mo(NCPh3)(CH-t-Bu)Np(OHIPT).
(cont.) Chapter 3. Reactions of Mo Bispyrrolide Complexes with Enantiomerically Pure Diols: In Situ Catalyst Generation and Studies of Olefin Metathesis Reactions In the Fume Hood. Reactions of bispyrrolide molybdenum complexes Mo(NAd)(CHCMe2Ph)(pyr)2 and Mo(N-2-6-i-Pr2C6H3)(CHCMe2Ph)(pyr)2 with (R)-BiphenH2, and (R)-Benz2BitetH2 were examined (pyr = C4H4N, Benz2BitetH2 = 3,3'-dibenzhydryl-5,5',6,6',7,7',8,8'-octahydro-1,1'- binaphthyl-2,2'-diol). The resulting in situ generated catalysts were studied in three olefin metathesis reactions. These systems were found to be as active and enantioselective as the analogous isolated complexes. When the stock solutions of Mo(NAd)(CHCMe2Ph)(pyr)2, Mo(N- 2,6-i-Pr2C6H3)(CHCMe2Ph)(pyr)2, (R)-BiphenH2, and (R)-Benz2BitetH2 were stored in the fume hood over a period of one month, the in situ prepared catalysts were determined to be nearly identical in terms of their catalytic properties to the catalysts generated in situ in the glovebox.
by Tatiana Pilyugina.
Ph.D.
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7

Mann, Tyler J. "Stereoselective Olefin Metathesis Reactions Catalyzed by Molybdenum Monoaryloxide Monopyrrolide Complexes." Thesis, Boston College, 2016. http://hdl.handle.net/2345/bc-ir:104995.

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Thesis advisor: Amir H. Hoveyda
Chapter 1: Efficient Z-Selective Cross-Metathesis of Secondary Allylic Ethers Efficient Z-selective cross-metathesis of secondary allylic ethers were catalyzed by monoaryloxide monopyrrolide molybdenum complexes. Reactions involving both silyl and benzyl protected ethers were demonstrated, as well as ethers containing alkyl, aryl and alkynyl substituents. Mechanistic studies were performed, and the reactions were applied to the total synthesis of several ene-diyne natural products. Chapter 2. Stereoselective Total Synthesis of Disorazole C1 The stereoselective total synthesis of disorazole C1 is reported. The synthesis was completed in 12 longest linear steps. Our synthesis demonstrates the utility of Z-selective cross-metathesis to form both alkenyl borons and alkenyl halides. Another key transformation was a one-pot Suzuki-dimerization reaction to form a symmetric 30 membered ring in relatively high yield. Chapter 3. Stereoselective Cross-Metathesis to Form Trisubstituted Alkenes Initial studies into the stereoselective formation of trisubstituted olefins through molybdenum catalyzed cross-metathesis have been performed. Our mechanistic understanding of the reaction lead us to focus on the synthesis of alkenyl halides, which can be obtained in up 90% yield and 75:25 E:Z selectivity. Chapter 4: Ring-Closing Metathesis in the Synthesis of Natural Products Development of highly efficient and selective ring-closing metathesis reactions have enabled collaborators to successfully implement routes in total synthesis endeavors. A diastereoselective seven-membered ring-closing metathesis enabled the successful synthesis of (±)-tetrapetalone A methyl-aglycon. An enantioselective ring-closing metathesis to form a six membered ring has provided access to enantioenriched aspidosperma alkaloids
Thesis (PhD) — Boston College, 2016
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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8

Brown, Gavin M. "Synthesis and screening of ligands for catalytic olefin oligomerisation reactions." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/6275.

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A set of reliable, one-pot reactions have enabled the preparation of a wide variety of novel bidentate (and potentially monodentate) ligands bearing a combination of P, N and C atoms across the backbone. The coordination capabilities of these phosphines have been explored with a variety of transition metal centres including PtII, PdII, RuII, IrIII, AuI and Cr0 confirming the versatility of this group of compounds when acting as bi- and monodentate ligands as well as the ability to bridge two metal centres. Reaction of a substituted hydroxymethylphosphine (R'2PCH2OH) with a primary amine in methanol gave the diphosphine ligands R'2PCH2N(R)CH2PR'2 including a PCNCP backbone. The steric and electronic properties of these ligands were tuned by the simple interchanging of the R/R' substituents attached to the P and N atoms. These compounds have been fully characterised by spectroscopic and analytical methods and reacted with transition metal precursors of the type MCl2(COD) (M = Pd/Pt) to yield complexes incorporating six-membered chelate rings. In addition to the aforementioned symmetric PCNCP ligands, the new non-symmetric ditertiary compounds Ph2PCH2N(R)CH2PAd were prepared using a three-step sequence of condensation reactions. Novel ligands incorporating a PCNP backbone were synthesised via a single condensation reaction between Ph2PCH2OH and a primary amine to give the secondary aminophosphines Ph2PCH2N(H)R. Deprotonation of the secondary amine followed by addition of neat R'2PCl resulted in the formation of the ligands Ph2PCH2N(R)PR'2. This group of compounds was characterised utilising similar techniques to their PCNCP analogues with their coordinative capabilities also assessed. The catalytic properties of a select group of the diphosphines prepared, when coordinated to a CrIII precursor, were analysed at Sasol Technology (Pty) Ltd under their standard conditions for ethylene oligomerisation reactions. Initial results established that ligands were effective as catalysts with the exception of those incorporating phospha-adamantane cages. Ligand 3.8 with a PCNP backbone was found to be comparable, in terms of activity, to Sasol's current PNP tetramerisation systems.
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9

Finnegan, David Francis. "Tandem Reactions Involving Ruthenium Alkylidenes." Thesis, Boston College, 2009. http://hdl.handle.net/2345/728.

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Thesis advisor: Marc L. Snapper
Tandem Reactions have proven themselves to be useful reactions for the synthesis of highly complex materials. Ruthenium alkylidenes are shown to be useful precursors for the development of new tandem processes. First, a new tandem metathesis/hetero-Pauson-Khand process is developed using Grubbs' second generation catalyst. Next, various metatheis/olefin isomerization processes are explored
Thesis (PhD) — Boston College, 2009
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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10

Lundin, Angelica. "Quantum chemical studies of olefin epoxidation and benzyne biradicals /." Göteborg, Sweden : Göteborg University, Faculty of Science, 2007. http://www.loc.gov/catdir/toc/fy0801/2007440811.html.

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Книги з теми "Olefin reactions"

1

T, Balaban Alexandru, and Dimonie M, eds. Olefin metathesis and ring-opening polymerization of cyclo-olefins. 2nd ed. Bucureşti: Editura Academiei, 1985.

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NATO Advanced Study Institute on Olefin Metathesis and Polymerization Catalysts (1989 Akçay, Balıkesir İli, Turkey). Olefin metathesis and polymerization catalysts: Synthesis, mechanism, and utilization. Dordrecht: Kluwer, 1990.

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Lundin, Angelica. Quantum chemical studies of olefin epoxidation and benzyne biradicals. Göteborg, Sweden: Göteborg University, Faculty of Science, 2007.

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Grela, Karol. Olefin Metathesis: Theory and Practice. Wiley, 2014.

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Grela, Karol. Olefin Metathesis: Theory and Practice. Wiley & Sons, Limited, John, 2014.

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Grela, Karol. Olefin Metathesis: Theory and Practice. Wiley & Sons, Incorporated, John, 2014.

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7

Grela, Karol. Olefin Metathesis: Theory and Practice. Wiley & Sons, Incorporated, John, 2014.

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Grela, Karol. Olefin Metathesis: Theory and Practice. Wiley & Sons, Incorporated, John, 2014.

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9

Ivin, K. J., and J. C. Mol. Olefin Metathesis and Metathesis Polymerization. Elsevier Science & Technology Books, 1997.

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Olefin Metathesis and Metathesis Polymerization, Second Edition. 2nd ed. Academic Press, 1997.

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Частини книг з теми "Olefin reactions"

1

Li, Jie Jack. "Olefin Metathesis." In Name Reactions, 407–11. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-50865-4_110.

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Li, Jie Jack. "Sharpless olefin synthesis." In Name Reactions, 555–56. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-03979-4_251.

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3

Jack Li, Jie. "Sharpless olefin synthesis." In Name Reactions, 505–6. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-01053-8_235.

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4

Kaminsky, W., and R. Kramolowsky. "Olefin Polymerization." In Inorganic Reactions and Methods, 298–99. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470145319.ch107.

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5

Harutyunyan, Syuzanna, Anna Michrowska, Karol Grela, Stephen J. Connon, Aideen M. Dunne, Siegfried Blechert, G. Bhaskar, and B. Venkateswara Rao. "Olefin Metathesis Reactions." In Catalysts for Fine Chemical Synthesis, Volume 3, Metal Catalysed Carbon-Carbon Bond-Forming Reactions, 169–80. Chichester, UK: John Wiley & Sons, Ltd, 2005. http://dx.doi.org/10.1002/0470862017.ch9.

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6

Li, Jie Jack. "Ramberg—Bäcklund olefin synthesis." In Name Reactions, 328. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-662-05336-2_245.

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7

Li, Jie Jack. "Corey-Winter olefin synthesis." In Name Reactions, 93–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-662-05336-2_73.

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8

Li, Jie Jack. "Corey–Winter olefin synthesis." In Name Reactions, 182–84. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-03979-4_75.

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9

Li, Jie Jack. "Ramberg-Bäcklund olefin synthesis." In Name Reactions, 297. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04835-1_234.

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10

Li, Jie Jack. "Corey-Winter olefin synthesis." In Name Reactions, 82–83. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04835-1_68.

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Тези доповідей конференцій з теми "Olefin reactions"

1

Cheenkachorn, Kraipat, Wallis A. Lloyd, and Joseph M. Perez. "Use of Pressurized Differential Scanning Calorimetry (PDSC) to Evaluate Effectiveness of Additives in Vegetable Oil Lubricants." In ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0657.

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Use of renewable resources to replace petroleum base stocks in lubricants is attractive. Research on additives enhanced by current advances in genetic and chemical modifications has resulted in improved oxidative stability of vegetable oils. Like most oxidation processes, the oxidative degradation of vegetable oils is complex. The auto-oxidation free radical mechanisms and hydroperoxide theories of oxidation have been well studied. Factors that influence the degradation of oils include temperature, surface reactivity, rates of formation of radicals, chemical composition factors such as olefin and aromatic content and additive effectiveness. This uses pressurized differential scanning calorimetry to evaluate the oxidative stability of four biodegradable fluids with and without additives. The oleic acid content of the four fluids ranged from 83 to 23 percent. Reaction kinetics are used to explain observed differences in phase transformation and polymerization reactions. Additive selection to obtain maximum effectiveness in the base stocks is reported.
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2

Bolotov, Vasiliy Alexandrovich, Serguei Fedorovich Tikhov, Konstantin Radikovich Valeev, Vladimir Timurovich Shamirzaev, and Valentin Nikolaevich Parmon. "SELECTIVE FORMATION OF LINEAR ALPHA-OLEFINS VIA MICROWAVE CATALYTIC CRACKING OF LIQUID STRAIGHT-CHAIN ALKANES." In Ampere 2019. Valencia: Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/ampere2019.2019.9894.

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Linear even-carbon-number alpha-olefins (LAO) with four or more carbon atoms are important compounds of high demand in chemical industry as precursors of a wide range of value-added chemicals [1]. LAO are used as co-monomers for polyethylene production, for the production of alcohols (mainly in detergents and plasticizers) and for synthesis of polyalphaolefins (used in synthetic lubricants). Alpha-olefins (C4, C6, C8 and C10) are mainly used to produce poly(vinyl chloride) plasticizers, high-density and linear low-density polyethylene to impart the stress-crack resistance. C10–C14 alpha-olefins can be used to synthesize linear alkylbenzene sulfonates (synthetic detergents). A conventional route to produce alpha-olefins is oligomerization of ethylene. The process provides production of high quality alpha-olefins but is very costly. If not oligomerization, LAO can be produced by thermal cracking of waxy paraffins but the product is not pure and contains numerous internal olefins, dienes and paraffin impurities. The process is conducted in the vapor phase at relatively low cracking temperatures and needs rapid quenching to prevent side reactions such as isomerization or cyclization. In our previous work [2], we showed that the selectivity to alpha-olefins can be increased considerably via catalytic cracking of n-alkanes under selective MW heating of catalysts. In the present work, the general regularities of MW cracking of n-alkanes are presented. Porous ceramic matrix Al2O3/Al composites (ceramometals) and various carbon materials (CM) having high dielectric losses were studied as supports of the catalysts. MW cracking was conducted with n-C16H34 and n-C28H58. The influence particle size and surface morphology of ceramometals and CM on the structural and group composition of the products was studied. It was established that LAO (C2-C23) and n-alkanes (C2-C26) were the main cracking products under selective MW heating of the used supports. The quantitative analysis of the products demonstrated that the liquid-phase process is more selective to alpha-olefins at the MW catalytic cracking than at the convectional thermal cracking. Silica modification of the surface of CM was shown to suppress spark discharge (usually observed at MW heating of CM); hence, the thermal cleavage of C-C bonds on the CM surface but not in the plasma discharge contributes the most to the formation of radicals. It was shown that the selectivity to liquid alpha-olefin could be more than 85 % under MW heating of cermets in region of the E - field node and decrease considerably in the region of H - field node.
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3

Ye, Jiping, Kenichi Ueoka, Makoto Kano, Yoshiteru Yasuda, Yusuke Okamoto, and Jean Michel Martin. "Super Low Friction Property of DLC Lubricated With Ester-Containing Oil: Part 2 — Nanometer-Scale Morphological, Structural and Frictional Properties." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63921.

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We have succeeded for the first time anywhere in lowering the friction coefficient of a diamond-like-carbon (DLC) coating to less than 0.01 under boundary lubrication in engine oil [1–3]. This anomalous super-lubrication behavior has been observed for a hydrogen-free DLC-coated (ta-C) disc in an ester-containing oil but not for a hydrogenated DLC (a-C:H) coating. It is thought that some chemical adsorbent may form only on the ta-C sliding surface due to some tribochemical reactions. Our recent studies have suggested that the macro-scale reduction of friction is dependent on nanometer-scale tribological properties [4–6]. The superlow friction behavior seen in a pin-on-disc friction test was taken as the object of this investigation with an eye toward elucidating the mechanism of the anomalous friction reduction. Pin-on-disc tests were conducted by sliding a ta-C/ta-C pair in the presence of poly alpha-olefin based oil containing a modifier additive of glycerol monooleate ester (PAOES1 oil). Nanometer-scale tribological properties were investigated by using atomic force microscopy (AFM), the AFM phase-image technique, and nanoscratch measurements. Attention was focused on the differences in surface roughness, nanostructure and nanofriction coefficient between the sliding and non-sliding areas in an effort to find the origin of the super-lubrication behavior.
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4

Grubbs, Robert H. "Design and applications of selective reactions of olefins." In 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-3-speach.

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5

Frota, Carlise, Caio Costa Oliveira, and Carlos R. D. Correia. "Study on the intermolecular Enantioselective Heck-Matsuda reaction of acyclic olefin diol." In 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-bmos2013_2013913204933.

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6

Mamin, E. A., B. E. Krisyuk, A. V. Mayorov, V. A. Ovchinnikov, P. M. Tyubaeva, and A. A. Popov. "Influence of haloid substitution and conjugation on ozone-olefine reaction." In PROCEEDINGS OF THE ADVANCED MATERIALS WITH HIERARCHICAL STRUCTURE FOR NEW TECHNOLOGIES AND RELIABLE STRUCTURES. Author(s), 2018. http://dx.doi.org/10.1063/1.5083430.

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7

Dalle Vacche, Sara. "Bio-based cationic waterborne polyurethane dispersions from high oleic soybean oil." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/xdga8424.

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Polymeric materials are under tremendous pressure for improving their greenness: despite their important role in several essential aspects of human life, in public opinion they are mostly associated with single-use plastics pollution and use of fossil resources. Sustainable polymer-based materials may be prepared from biobased monomers and polymers, through photoinduced processes. Owing to low energy requirements, high reaction rates at room temperature, and low VOC emissions, photoinduced polymerization is recognized as a green technology. Among the biobased monomers explored in this field, those derived from cardanol (a natural phenolic lipid obtained from cashew nutshell liquid) and from unsaturated vegetable oils, such as soybean oil, are interesting for industrial applications, being commercially available. However, polymers obtained by photoinduced polymerization of biobased monomers often have low thermomechanical properties; biobased monomers are thus typically used as co-monomers to increase the biobased content of fossil-based polymers, in non-structural applications, such as coating or adhesives, or are added with reinforcements to obtain composite materials. The latter option is particularly interesting when natural fillers, such as cellulosic fibers, are used, thus obtaining fully biobased composites. In our group we exploited photoinduced reactions to produce composites from biobased monomers, using wood-based microfibrillated cellulose and nanocellulose from hemp waste fibers as reinforcements. Two routes were explored: (i) epoxidized and (meth)acrylated monomers derived from cardanol and from soybean oil, were polymerized by photoinduced radical or cationic chain growth reactions; (ii) copolymer latexes obtained from derivatives of eugenol and coumarin were crosslinked through a photocycloaddition reaction. In the latter case, the potential reversibility of the crosslinking was explored in view of recyclability. The photoinduced polymerization and crosslinking reactions were studied by Fourier Transform Infrared (FTIR) and UV-visible spectroscopies; high degrees of conversion were obtained. The thermal, mechanical, and functional properties of these composites make them interesting for e.g., packaging applications.
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SANTOS, Maricel del Valle, Alexis Rafael VELEZ, and Ivana Maria MAGARIO. "EFFECT OF MOLAR WEIGHT OF CARBOXYLIC ACIDS ON THE ENZYMATIC ESTERIFICATION OF GLYCEROL." In SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY 2021 INTERNATIONAL VIRTUAL CONFERENCE. DR. D. SCIENTIFIC CONSULTING, 2022. http://dx.doi.org/10.48141/sbjchem.21scon.13_abstract_santos.pdf.

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Glycerol is a by-product in biodiesel synthesis, and its current market condition allows the possibility to transform into value-added compounds. In this work, the enzymatic esterification between glycerol and carboxylic acids of different molar weights was studied to obtain glycerides of industrial relevance. Therefore, eight different carboxylic acids were evaluated: formic, acetic, levulinic, caprylic, capric, lauric, stearic, and oleic. Immobilized lipase from Candida Antarctica was employed as a catalyst. Solvent-free reactions were carried out at 65 °C, 450 rpm, at a molar ratio of glycerol: carboxylic acid of 1:1 and a 1,6% enzyme concentration (based on reagents weight). Conversion of carboxylic acids was followed with time by titration. Under these conditions, acids from octanoic to oleic, which initially formed biphasic systems with glycerol, showed high conversions (68%-80%) and initial reaction rates in the same magnitude order. On the other hand, no enzymatic catalysis was observed with formic, acetic, and levulinic acids. Formic acid exhibited a higher rate and 58% of conversion without catalyst. However, for acetic and levulinic acids, conversion was low in uncatalyzed reactions. Then, for these acids, toluene was added as a reaction solvent. As a result, conversions and initial rates increased for these lighter acids, indicating the need for a non-polar media or a biphasic character to activate the enzyme.
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Shui, Zhengfei, and Yuxin Huo. "Analysis of the reaction system of C4 olefin prepared by ethanol coupling based on machine learning." In 2022 IEEE International Conference on Artificial Intelligence and Computer Applications (ICAICA). IEEE, 2022. http://dx.doi.org/10.1109/icaica54878.2022.9844512.

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Garifullina, Chulpan Aydarovna, Ildar Ilyasovich Ibragimov, Ilya Mikhailovich Indrupskiy, Dmitriy Sergeevich Klimov, Ernest Sumbatovich Zakirov, and Rifkhat Zinnurovich Sakhabutdinov. "Investigation of CO2 Utilization Processes on Metal-Containing Fillers with Generation of Hydrogen and Hydrocarbons." In SPE Russian Petroleum Technology Conference. SPE, 2021. http://dx.doi.org/10.2118/206612-ms.

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Abstract Continuing consumption of fossil fuels around the world, which has led to an increasing concentration of carbon dioxide CO2 in the atmosphere and global climate change caused by greenhouse gases, has become one of the main challenges for humanity. Heterogeneous catalytic hydrogenation of carbon dioxide in order to obtain valuable carbon-containing products and materials is one of the decarbonization directions. There is much research in the world dedicated to the hydrogenation of CO2 to various hydrocarbons, such as methane, lower olefins, long-chain hydrocarbons, formic acid, methanol and higher alcohols, which are produced by catalytic reactions with various mechanisms. There are still significant challenges associated with the need for an external source of hydrogen, high process temperatures, and the development of active, selective, and stable catalysts that would be suitable for large-scale production. This paper presents results of research on a CO2 utilization method with hydrogen and hydrocarbons production – the transformation of wastes into a source of energy, which allows solving environmental and energy problems. The method described in this paper consists in the interaction of metallic fillers with water saturated with carbon dioxide in a reactor at low (room) temperatures and further analysis of the resulting gas mixture using a chromatograph. Qualitative and quantitative evaluation of the produced gas composition, study of the effect of reaction system volume, filler composition and structure, and process temperature on the reaction product yield are presented. The results of theoretical and experimental analysis of the reactions underlying the process are given, and the economic potential of the proposed laboratory method is evaluated.
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