Download or read book Density Functional Theory Studies of Selected Transition Metals Catalyzed C C and C N Bond Formation Reactions written by Xufeng Lin and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Density Functional Theory Studies of Selected Transition Metals Catalyzed C-C and C-N Bond Formation Reactions" by Xufeng, Lin, 林旭鋒, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DENSITY FUNCTIONAL THEORY STUDIES OF SELECTED TRANSITION METALS CATALYZED C-C AND C-N BOND FORMATION REACTIONS submitted by Xufeng LIN for the degree of Doctor of Philosophy at The University of Hong Kong in September 2007 This thesis presents theoretical investigations on selected transition metals catalyzed C-C and C-N bond formation reactions. Density functional theory (DFT) calculations were performed to explore the potential energy surfaces of (1) alkyl-alkyl cross-coupling reactions catalyzed by nickel-trinitrogen ligand complexes, and (2) amidation of C-H bonds and alkene aziridinations catalyzed by rhodium and ruthenium complexes. In the first part three catalytic cycles were examined for Ni-catalyzed Negishi alkyl-alkyl cross-coupling with the ligand of 2,2'',6'',2''''-terpyridine (tpy). The catalytic cycle that involves a sequence of oxidative addition-reductive elimination- transmetalation with the actual catalyst of Ni(tpy)-CH or Ni(tpy)-I [Ni(I)] was found to be feasible, and this provide some new insight into the chemistry of metal-catalyzed cross-coupling reactions. The oxidative addition undergoes in a two-step radical pathway to produce a Ni(III) species, and the Ni(III) speices undergo reductive elimination to afford the alkyl-alkyl coupled product. Bulk solvation effect was considered in examination of this catalytic cycle. Cross-coupling reactions of both primary and secondary alkyl iodides in reactions with organozinc reagent were compared. Based on these results a Ni-catalyzed Negishi cross-coupling reaction of a secondary alkyl bromide was investigated with the ligands of bis(oxazolinyl)pyridine (Pybox). Reductive elimination step was found to be irreversible and rate-determining in generating the coupled product. When Pybox is replaced (S)-(i-Pr)-Pybox with C symmetry, it was found that the racemic 1-bromoindane can be converted into the coupled product in S enantiomer with high enantioselectivity. This is accounted for higher free energy of activation needed for the reductive elimination step in generating the R enantiomer compared to the S enatiomer in the case of (S)-(i-Pr)-Pybox ligand. In the second part the intramolecular amidation of C-H bonds in carbamates and sulfonamate esters were examined with dirhodium tetracarboxylate [Rh(II)] as the catalyst. "Rh(II)-nitrene" complexes were found to be largely favorable in free energy compared to the staring materials or the "Rh(II)-phenyliodinane" complexes. The singlet and triplet states of a Rh(II)-nitrene complex are very close in energy, which was attributed to the π-π orbital interaction of nitrene and Rh. However, a singlet Rh(II)- nitrene undergoes C-H bond cleavage accompanied by N-H and C-N bond formation in a concerted pathway, whereas a triplet Rh(II)-nitrene undergoes C-H bond cleavage accompanied by only N-H formation to produce a biradical. A singlet pathway is favorable over its corresponding triplet pathway in free energy of activation. Rh(II)- catalyzed nitrene insertion into a C=C double bond in competition with insertion into a C-H bond was also examined with the unsaturated substrate of sulfonamate esters. Similar cases were found for the reaction systems in which intramolecular amidation of C-H bonds in the cyclohexane ring in a sulfamate ester is catalyzed by Ru-porphyrins. In all these catalytic systems, stereoselectiviti

Download or read book Density Functional Theory Studies of Selected Transition Metals Catalyzed C C and C N Bond Formation Reactions written by Xufeng Lin and published by . This book was released on 2007 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book DFT Studies on Transition Metal Mediated and Catalyzed C C Formation Reactions written by Ting Fan and published by . This book was released on 2014 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Carbon Carbon Coupling Reactions Based on Decarboxylation and Iron Catalyzed C H Activation written by Rui Shang and published by Springer. This book was released on 2016-12-09 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the latest developments in new catalytic C–C bond formation methods using easily accessible carboxylate salts through catalytic decarboxylation with good atom economy, and employing the sustainable element iron as the catalyst to directly activate C–H bonds with high step efficiency. In this regard, it explores a mechanistic understanding of the newly discovered decarboxylative couplings and the catalytic reactivity of the iron catalyst with the help of density functional theory calculation. The thesis is divided into two parts, the first of which focuses on the development of a series of previously unexplored, inexpensive carboxylate salts as useful building blocks for the formation of various C–C bonds to access valuable chemicals. In turn, the second part is devoted to several new C–C bond formation methodologies using the most ubiquitous transition metal, iron, as a catalyst, and using the ubiquitous C–H bond as the coupling partner.

Download or read book New Reactivity and Selectivity in Transition Metal catalyzed C C and C N Bond Forming Processes written by and published by . This book was released on 2015 with total page 881 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I. Palladium-Catalyzed Carbon-Carbon Bond Forming Cross-Couplings Chapter 1. Ligand-Controlled Palladium-Catalyzed Regiodivergent Suzuki-Miyaura Cross-Coupling of Allylboronates and Aryl Halides An orthogonal set of catalyst systems based on the use of two biarylphosphine ligands has been developed for the Suzuki-Miyaura coupling of 3,3-disubstituted and 3-monosubstituted allylboronates with (hetero)aryl halides. These methods allow for the regiodivergent preparation of either the ct- or the [gamma]-isomeric coupling product with high levels of site selectivity using a common allylboron building block. Preliminary investigations have demonstrated the feasibility of an enantioselective variant for the [gamma]-selective cross-coupling using chiral monodentate biarylphosphine ligands. Chapter 2. Palladium-Catalyzed Completely Linear-Selective Negishi Coupling of 3,3-Disubstituted Organozinc Reagents with Aryl and Vinyl Electrophiles A palladium-catalyzed general and completely linear-selective Negishi coupling of 3,3- disubstituted allyl organozinc reagents with (hetero)aryl and vinyl electrophiles has been developed. This method provided an effective means for accessing highly functionalized aromatic and heteroaromatic compounds bearing prenyl-type side chains. The utility of the current protocol was further illustrated in the concise synthesis of the anti-HIV natural product siamenol. Chapter 3. Palladium-Catalyzed Highly Selective Negishi Cross-Coupling of Secondary Alkylzinc Reagents with Aryl and Heteroaryl Halides The palladium-catalyzed Negishi cross-coupling of secondary alkylzinc reagents and heteroaryl halides with high levels of regioisomeric retention has been described. The development of a series of biarylphosphine ligands has led to the identification of an improved catalyst for the coupling of electron-deficient heterocyclic substrates. Preparation and characterization of oxidative addition complex (L)Pd(Ar)(Br) provided insight into the unique reactivity of palladium catalysts based on CPhos-type biarylphosphine ligands in facilitating challenging reductive elimination processes. Chapter 4. Mechanistic Studies on the Aryl-Trifluoromethyl Reductive Elimination from Pd(II) Complexes Based on Biarylphosphine Ligands A series of monoligated (L)Pd(Ar)(CF3) (L = dialkyl biarylphosphine) have been prepared and studied in an effort to shed light on the mechanism of the aryl-trifluoromethyl reductive elimination from these systems. Combined experimental and computational investigations revealed unique reactivity and binding modes of (L)Pd(Ar)(CF3) complexes derived from BrettPhos-type biarylphosphines. In contrast to a variety of C-C and C-heteroatom bond forming reductive eliminations, kinetic measurements showed this Ar-CF3 reductive elimination is largely insensitive to the electronic nature of the to-be-eliminated aryl substituent. Furthermore, the aryl group serves as the nucleophilic coupling partner in this reductive elimination process. The structure-reactivity relationship of biarylphosphine ligands was also investigated, uncovering distinct roles of the ipso-arene and alkoxy interactions in affecting these reductive elimination reactions. Part II. Copper-Catalyzed Carbon-Carbon and Carbon-Nitrogen Bond Formation via Olefin Functionalization Chapter 5. Copper-Catalyzed ortho C-H Cyanation of Vinylarenes A copper-catalyzed regioselective ortho C-H cyanation of vinylarenes has been developed. This method provides an effective means for the selective functionalization of vinylarene derivatives. A copper-catalyzed cyanative dearomatization mechanism is proposed to account for the regiochemical course of this reaction. This mechanism has been validated through density functional theory calculations. Computational studies revealed that the high level of ortho selectivity in the electrophilic cyanation event originates from a unique six-membered transition state that minimizes unfavorable steric repulsions. Chapter 6. Regio- and Stereospecific 1,3-Allyl Group Transfer Triggered by a Copper-Catalyzed Borylation/ortho-Cyanation Cascade A copper-catalyzed borylation/cyanation/allyl group transfer cascade has been developed. This process features an unconventional copper-catalyzed electrophilic dearomatization followed by the subsequent regio- and stereospecific 1,3-transposition of the allyl fragment enabled by the aromatization-driven Cope rearrangement. This method provides an effective means for the construction of adjacent tertiary and quaternary stereocenters with high levels of stereochemical purity. Chapter 7. Copper-Catalyzed Asymmetric Hydroamination of Unactivated Internal Olefins: an Effective Means to Access Highly Enantioenriched Aliphatic Amines Catalytic assembly of enantiopure aliphatic amines from abundant and readily available precursors has long been recognized as a paramount challenge in synthetic chemistry. We describe a mild and general copper-catalyzed hydroamination that effectively converts unactivated internal olefins-an important yet unexploited class of abundant feedstock chemicals-into highly enantioenriched [alpha]-branched amines (>/= 96% ee) featuring two minimally differentiated aliphatic substituents. This method provides a powerful means to access a broad range of advanced, highly functionalized enantioenriched amines of interest in pharmaceutical research and other areas.

Download or read book C X Bond Formation written by Arkadi Vigalok and published by Springer Science & Business Media. This book was released on 2010-07-09 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Kilian Muñiz: Transition Metal Catalyzed Electrophilic Halogenation of C-H bonds in alpha-Position to Carbonyl Groups; Arkadi Vigalok * and Ariela W Kaspi: Late Transition Metal-Mediated Formation of Carbon-Halogen Bonds; Paul Bichler and Jennifer A. Love*: Organometallic Approaches to Carbon-Sulfur Bond Formation; David S. Glueck: Recent Advances in Metal-Catalyzed C-P Bond Formation; Andrei N. Vedernikov: C-O Reductive Elimination from High Valent Pt and Pd Centers; Lukas Hintermann: Recent Developments in Metal-Catalyzed Additions of Oxygen Nucleophiles to Alkenes and Alkynes; Moris S. Eisen: Catalytic C-N, C-O and C-S bond formation promoted by organoactinide complexes.

Download or read book Cleavage of Carbon Carbon Single Bonds by Transition Metals written by Masahiro Murakami and published by John Wiley & Sons. This book was released on 2015-12-21 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by leading experts and pioneers in the field, this is the first up-to-date book on this hot topic. The authors provide synthetic chemists with different methods to activate carbon-carbon sigma bonds in organic molecules promoted by transition metal complexes. They explain the basic principles and strategies for carbon-carbon bond cleavage and highlight recently developed synthetic protocols based on this methodology. In so doing, they cover cleavage of C-C bonds in strained molecules, reactions involving elimination of carbon dioxide and ketones, reactions via retroallylation, and cleavage of C-C bonds of ketones and nitriles. The result is an excellent information source for researchers in academia and industry working in the field of synthetic organic chemistry, while equally serving as supplementary reading for advanced courses in organometallic chemistry and catalysis.

Download or read book Transition Metal Catalyzed Carbene Transformations written by Jianbo Wang and published by John Wiley & Sons. This book was released on 2022-05-16 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents an up-to-date overview of the rapidly growing field of carbene transformations Carbene transformations have had an enormous impact on catalysis and organometallic chemistry. With the growth of transition metal-catalyzed carbene transformations in recent decades, carbene transformations are today an important compound class in organic synthesis as well as in the pharmaceutical and agrochemical industries. Edited by leading experts in the field, Transition Metal-Catalyzed Carbene Transformations is a thorough summary of the most recent advances in the rapidly expanding research area. This authoritative volume covers different reaction types such as ring forming reactions and rearrangement reactions, details their conditions and properties, and provides readers with accurate information on a wide range of carbene reactions. Twelve in-depth chapters address topics including carbene C-H bond insertion in alkane functionalization, the application of engineered enzymes in asymmetric carbene transfer, progress in transition-metal-catalyzed cross-coupling using carbene precursors, and more. Throughout the text, the authors highlight novel catalytic systems, transformations, and applications of transition-metal-catalyzed carbene transfer. Highlights the dynamic nature of the field of transition-metal-catalyzed carbene transformations Summarizes the catalytic radical approach for selective carbene cyclopropanation, high enantioselectivity in X-H insertions, and bio-inspired carbene transformations Introduces chiral N,N'-dioxide and chiral guanidine-based catalysts and different transformations with gold catalysis Discusses approaches in cycloaddition reactions with metal carbenes and polymerization with carbene transformations Outlines multicomponent reactions through gem-difunctionalization and transition-metal-catalyzed cross-coupling using carbene precursors Transition Metal-Catalyzed Carbene Transformations is essential reading for all chemists involved in organometallics, including organic and inorganic chemists, catalytic chemists, and chemists working in industry.

Download or read book Density Functional Studies of Transition Metal Catalyzed Reactions written by Debasis Koley and published by . This book was released on 2005 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book C C Bond Activation written by Guangbin Dong and published by Springer. This book was released on 2014-09-18 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry presents critical reviews of the present and future trends in modern chemical research. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field. Review articles for the individual volumes are invited by the volume editors. Readership: research chemists at universities or in industry, graduate students

Download or read book Transition Metal olefin Bonding Interactions written by Michael J. Berninger and published by . This book was released on 2015 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-olefin equilibrium geometries, bond formation energies (DeltaE), enthalpies (DeltaH), and free energies (DeltaG) for a select series of transition metal (M = Ni, Fe, Cr, Mo and W) -olefin carbonyl complexes [M(CO) x(eta2-C2H3-C6H4-Y)] have been calculated and compared using density functional theory (DFT), with the BP86 functional under standard state conditions (1 atm, 298.15 K) for the general gas phase formation reaction: M(CO)x + (C2H3-C6H4 -Y) → [M(CO)x(eta2-C2H3-C6H4-Y)] (1).

Download or read book Earth Abundant Transition Metal Catalyzed Reactions written by and published by Elsevier. This book was released on 2024-09-18 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth-Abundant Transition Metal Catalyzed Reactions, Volume 74 in the Advances in Catalysis series, highlights new advances in the field, with this new volume presenting interesting chapters. Each chapter is written by an international board of authors. Chapters in this new release include in Chiral Iron Complexes for Asymmetric Catalysis, Recent advances in Ni-catalyzed Functionalization of Strong C-O and C-H Bonds, Low-valent Molecular Cobalt Complexes for Reductive Chemistry, Iron-catalyzed group-transfer reactions with hypervalent iodine reagents, and Iron Porphyrins for Mediating Atom Efficient C–C Bond Formations. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in Advances in Catalysis serials Updated release includes the latest information in the field

Download or read book C H and C X Bond Functionalization written by Xavi Ribas and published by Royal Society of Chemistry. This book was released on 2013-05-24 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cross-coupling reactions involving C-H and C-X bond functionalisation are commonplace in natural product synthesis and natural products, therapeutic agents, biological probes, and advanced materials. Much attention has been given to understanding the mechanistic strategies used to achieve this, making this a hot topic in recent years. In this edited book, contributions from across the globe examine these strategies, with a particular focus on palladium and copper, as well as iron – an emerging element in this field. Reviewing the recent literature, the book presents an in-depth understanding of the field, guiding the reader to achieving the best synthetic strategies for aromatic functionalisation. Organic and Organometallic chemists, as well as natural product and pharmaceutical scientists, will find this an essential guide to a major transformation currently underway in synthetic chemistry.

Download or read book Transition Metal Catalyzed Oxidative Cross Coupling Reactions written by Aiwen Lei and published by Springer. This book was released on 2019-02-04 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive text covering the research and development trends in the booming field of transition metal catalyzed oxidative cross-coupling reactions. Oxidative cross-coupling reaction is a new method to forming chemical bonds besides the traditional cross-coupling reactions. This book provides the answers to how this coupling reaction occurs and what its advantages are. The palladium, copper and iron catalyzed oxidative cross-coupling reactions as the main focuses of interest are described in detail. The oxidative cross-coupling reactions catalyzed by other metals and transition-metal-free oxidative coupling reactions are also introduced.This book provides a useful reference source for researchers and graduates in the field of transition metal catalyzed coupling reactions. It is also valuable to researchers working in pharmaceutical companies, fine organic chemical companies, and etc.

Download or read book A Chemist s Guide to Density Functional Theory written by Wolfram Koch and published by John Wiley & Sons. This book was released on 2015-11-18 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Chemists familiar with conventional quantum mechanics will applaud and benefit greatly from this particularly instructive, thorough and clearly written exposition of density functional theory: its basis, concepts, terms, implementation, and performance in diverse applications. Users of DFT for structure, energy, and molecular property computations, as well as reaction mechanism studies, are guided to the optimum choices of the most effective methods. Well done!" Paul von Rague Schleyer "A conspicuous hole in the computational chemist's library is nicely filled by this book, which provides a wide-ranging and pragmatic view of the subject.[...It] should justifiably become the favorite text on the subject for practioneers who aim to use DFT to solve chemical problems." J. F. Stanton, J. Am. Chem. Soc. "The authors' aim is to guide the chemist through basic theoretical and related technical aspects of DFT at an easy-to-understand theoretical level. They succeed admirably." P. C. H. Mitchell, Appl. Organomet. Chem. "The authors have done an excellent service to the chemical community. [...] A Chemist's Guide to Density Functional Theory is exactly what the title suggests. It should be an invaluable source of insight and knowledge for many chemists using DFT approaches to solve chemical problems." M. Kaupp, Angew. Chem.

Download or read book Chemistry Beyond Chlorine written by Pietro Tundo and published by Springer. This book was released on 2016-09-17 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the industrial revolution, chlorine remains an iconic molecule even though its production by the electrolysis of sodium chloride is extremely energy intensive. The rationale behind this book is to present useful and industrially relevant examples for alternatives to chlorine in synthesis. This multi-authored volume presents numerous contributions from an international spectrum of authors that demonstrate how to facilitate the development of industrially relevant and implementable breakthrough technologies. This volume will interest individuals working in organic synthesis in industry and academia who are working in Green Chemistry and Sustainable Technologies.

Download or read book Transition Metal Catalyzed C N Bond Formation Via Addition of Nitrogen Nucleophiles Towards Alkenes and Related Tandem Cyclization Reactions written by Dong Xing and published by Open Dissertation Press. This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Transition Metal-catalyzed C-N Bond Formation via Addition of Nitrogen Nucleophiles Towards Alkenes and Related Tandem Cyclization Reactions" by Dong, Xing, 邢栋, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b4658915 Subjects: Ring formation (Chemistry) Transition metal catalysts Polycyclic compounds - Synthesis