Download or read book Developments and Applications of Methods for Palladium and Copper catalyzed Carbon nitrogen Bond Formation written by Jeffrey Chih-Yeh Yang and published by . This book was released on 2018 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies presented in this dissertation are aimed at the development and application of methodologies that enable carbon-nitrogen (C-N) bond formation catalyzed by late transition metals such as palladium and copper. The first part of this thesis focuses on the use of palladium catalysis for the construction of a carbon(sp2)-nitrogen bond in the context of a biphasic continuous-flow system (Chapter 1). The second part of this thesis describes the recent developments of copper-hydride (CuH) catalyzed asymmetric hydroamination for the formation of a-chiral carbon(sp3)-nitrogen bonds from olefins. This work includes the application of CuH catalysis to the synthesis of chiral N-alkyl aziridines (Chapter 2), and the discovery and development of novel electrophilic amines to enable CuH-catalyzed asymmetric hydroamination to directly access primary amines (Chapter 3). Part I. Chapter 1. Use of a "Catalytic" Cosolvent, N,N-Dimethyl Octanamide, Allows the Flow Synthesis of Imatinib with no Solvent Switch A general, efficient method for C-N cross-coupling has been developed using N,N-dimethyloctanamide as a cosolvent for biphasic continuous-flow applications. In addition to utilizing a proper co-solvent, the described method harnesses the superior mixing abilities of a stainless-steel powder packed tube reactor to efficiently couple a wide range of aryl/heteroaryl halides and aryl/heteroaryl/alkyl amines in a short period of time (

Download or read book Development and Application of Palladium catalyzed Carbon nitrogen Bond Forming Reactions written by Seble-Hiwot Teshome Wagaw and published by . This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Amination and Formation of sp2 C N Bonds written by Marc Taillefer and published by Springer. This book was released on 2013-12-12 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Palladium-Catalyzed sp2C–N Bond Forming Reactions: Recent Developments and Applications. Metal-catalyzed C(sp2)-N bond formation.- Recent Developments in Recyclable Copper Catalyst Systems for C−N Bond Forming Cross-Coupling Reactions Using Aryl Halides and Arylboronic Acids. Assembly of N-containing heterocycles via Pd and Cu-catalyzed C-N bond formation reactions. Copper-Catalyzed C(aryl)-N Bond Formation.

Download or read book New Pd and Cu based Catalysts for Carbon heteroatom Bond Formation written by Nootaree Niljianskul and published by . This book was released on 2015 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this dissertation is aimed at the development of novel methodologies for carbon-heteroatom cross-coupling reactions catalyzed by late-transition metals. Both palladium and copper are central to the field of transition metal-catalysis and are integral to the catalyst systems developed as part of our continual advancement in cross-coupling reactions. The first part of this thesis focuses on the use of palladium catalysts to form carbon-sulfur bonds directed towards aryl sulfonamide synthesis. The second part of the thesis describes the recent development in the copper(!) hydride mediated formation of carbon-nitrogen bonds via hydroamination of olefins. Part I. Chapter 1. Palladium-Catalyzed Chlorosulfonylation of Arylboronic Acids Using a biaryl phosphine ligand platform, the first palladium-catalyzed cross-coupling reaction of phenyl chlorosulfate with arylboronic acids was achieved. In this context, the arylsulfonyl chloride products serve as useful precursors to a variety of sulfonyl functional groups, such as aryl sulfonamides, aryl sulfones, and arenesulfonate esters. In particular, this method allows for the preparation of a number of arylsulfonyl chlorides that are not accessible via electrophilic aromatic substitution pathways and under mild reaction conditions. Additionally, this methodology points to an unprecedented selectivity for the phenylchlorosulfate electrophiles used in the cross-coupling reactions. Part II. Chapter 2. Enantio- and Regioselective Copper-Catalyzed Hydroamination of Styrenes and the Extension of the Methodology towards Anti-Markovnikov Hydroamination of Terminal Aliphatic Alkenes The development of a copper-mediated strategy towards the hydroamination of styrene derivatives is reported. In this system, the reaction proceeds regioselectively and enantioselectively to generate [alpha]-branched amines. The system can transform a wide variety of substituted styrenes, including trans-, cis-, and [beta]-disubstituted styrenes. In addition, our extension to copper-catalyzed hydroamination reactions of unactivated aliphatic olefins is reported. Using terminal aliphatic alkenes, the copper-catalyzed hydroamination reactions proceed with anti-Markovnikov regioselectivity. Preliminary results point to the application of this methodology towards [beta]-chiral amine synthesis via the hydroamination of I, 1-disubstituted alkenes. Chapter 3. [alpha]-Aminosilane Synthesis via Copper-Catalyzed Hydroamination of Vinylsilanes The copper-catalyzed hydroamination of vinylsilanes is described. This regioselective reaction generates a-chiral aminosilanes in high yields and enantioselectivities. The method is compatible with differentially substituted vinylsilanes and allows access to many valuable chiral organosilicon compounds. Chapter 4. Synthesis of [gamma]-Chiral Amines via Copper-Catalyzed Hydroamination of 3,3- Disubstituted Allylic Alcohols and 3,3-Disubstituted Allylic Benzoates An investigation into the copper-catalyzed hydroamination of allylic alcohols and allylic benzoates is reported. The reaction proceeds via a [beta]-alkoxy elimination, setting a stereogenic center at the 3-postion to generate [gamma]-chiral amine products. The reaction is more efficient using allylic benzoates. This method is completely regioselective and is applicable to aliphatic allylic benzoates as well as aromatic allylic benzoates. Additionally, we demonstrated that this strategy is applicable towards an allylic epoxide substrate to generate [delta]-chiral amine.

Download or read book Palladium Catalyzed Carbon nitrogen Bond Formation written by Alejandra Domínguez Huerta and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis describes the design and development of reductive amination methodologies of unactivated carbon-oxygen bonds using palladium on charcoal as a heterogeneous catalyst. The underlying premise is the transformation of starting materials that can be obtained from bio-renewable resources into commodity chemicals. Specifically, 2-cyclohexen-1-one and phenol were used as lignin building-block surrogates for C-N bond formation. The first chapter places the work developed in this thesis both in a global and a scientific context. Its objective is to provide an overview of our societal needs while describing the latest scientific developments related to this thesis topic. Thus, it begins by exploring the United Nation's Sustainable Goals, followed by an overview of petroleum and lignin chemistry, and finishes with a review on amino acid N-modification. In chapter two, the development of a novel methodology for the N-arylation of [alpha]-amino acids using 2-cyclohexen-1-one is described. Palladium on carbon was chosen as the catalyst, and several reaction conditions were explored to obtain optimal yields. This methodology's attractiveness lies in the absence of an aryl halide or protecting group on the 2-cyclohexen-1-one for the N-arylation to proceed. The reaction requires substoichiometric amounts of base and oxygen as the terminal oxidant. Aliphatic amino acids were ideal substrates for the reaction, and cyclohexanone provided the N-biarylated amino acids in good yields (up to 74%). Chapter three describes efforts to improve the harsh conditions required for the N-arylation of [alpha]-amino acids, resulting in the development of a novel methodology for their N-cyclohexylation in water, at room temperature, using phenol as a coupling partner. The reaction successfully achieves N-cyclohexylation for 17 out of the 20 naturally occurring amino acids without racemization with up to quantitative yields. Furthermore, small peptides were also successful substrates for the reaction. The fourth chapter explores the possibility of applying the latter methodology for the formation of one- and two-component peptide staples using tyrosine as a handle. The one component staple was investigated using acetyl-lysine and acetyl-tyrosine, while the two-component staple was investigated using acetylated-tyrosine 2,2'-(ethylenedioxy)bis(ethylamine). While model substrates proved to couple successfully under previously optimized conditions, concentration and characterization proved to be challenging for working with larger peptides. Additional experiments exploring the possibility of using tyrosine amination as a pH responding hydrogel are also described in this chapter. Finally, chapter five explores the possibility of synthesizing diphenylamines from phenol and ammonia formate as a convenient ammonia surrogate. Seventeen different diarylamines were synthesized with palladium on charcoal as the catalyst, with yields ranging from good to excellent. Notably, water and CO2 were the only byproducts generated from this transformation. Triphenylamine was also obtained in combination with the methodology described in Chapter 1"--

Download or read book Recent Advances in Copper and Palladium catalyzed Carbon heteroatom and Carbon carbon Bond formation written by Ryan Alan Altman and published by . This book was released on 2008 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-catalyzed nucleophilic substitution reactions of aryl halides have become one of the most valuable and useful classes of reactions developed in the last 30 years. Foremost among these processes are the classes of palladium- and copper-catalyzed reactions, which employ heteroatom-based nucleophiles. Herein, newly designed catalyst systems are presented for the palladium- and/or copper-catalyzed nucleophilic substitution reactions of aryl halides with a variety of nucleophiles, including (benz)imidazoles, oxindoles, 2-, 3- and 4-hydroxypyridines, anilines, and aliphatic, benzylic, allylic and propargylic alcohols. In many cases, catalyst optimization and ligand structure are discussed and evaluated. Where applicable, the palladiumand copper-based catalyst systems are contrasted to demonstrate the complementary relationships between the employment of these two metals. Chapter One Chapter Two Chapter Three Chapter Four Chapter Five. Palladium- and Copper-catalyzed Reactions of Imidazoles and Benzimidazoles with Aryl Halides. Orthogonal Selectivity in Copper- and Palladium-catalyzed Reactions of Aryl Halides with Oxindoles. Copper-catalyzed Reactions of Hydroxypyridines and Related Compounds with Aryl Halides. Pyrrole-2-carboxylic Acid as a Ligand for the Copper-catalyzed Reactions of Primary Anilines with Aryl Halides. An Improved Copper-based Catalyst System for the Reactions of Aryl Halides with Aliphatic Alcohols.

Download or read book THE DEVELOPMENT AND APPLICATION OF NEW PALLADIUM CATALYSTS IN CHALLENGING C N AND C O BOND FORMING REACTIONS written by Christopher B. Lavery and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Development of Palladium and Copper catalyzed Transformations for the Asymmetric Synthesis of Biologically Active Small Molecules written by James Thomas Masters and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The continued demand for efficient chemo-, regio-, and stereoselective organic transformations motivates the development of new chemical reactions. Transition metal catalysis represents a powerful method for the construction of carbon-carbon, carbon-hydrogen, and carbon-heteroatom bonds in a highly selective fashion. This dissertation describes the development of several new transition metal-catalyzed organic reactions useful in the preparation of various chiral small molecules, including both fundamental organic "building block" compounds and structurally complex natural products and pharmaceutical agents. We report a new strategy for the synthesis of chiral beta-alkynyl esters, ketones, and sulfones via sequential palladium-catalyzed carbon-carbon bond formation and copper-catalyzed carbon-hydrogen bond formation. The process is operationally straightforward, compatible with a broad range of substrates, and delivers the targets in high yields with excellent levels of enantioselectivity. It is compatible with both oxygen and nitrogen functionality, and this enabled the rapid elaboration of the products into a diverse set of chiral heterocycles. The sequential catalysis protocol was employed in a concise, enantioselective synthesis of AMG 837, a potent agonist of G-protein coupled receptor 40. Recognizing both the biological relevance of chiral alkaloids and the synthetic challenges associated with the construction of quaternary, all-carbon stereocenters, we pursued a palladium-catalyzed asymmetric allylic alkylation that effected carbon-carbon bond formation on prochiral oxindole nucleophiles. Although prior research has demonstrated that allylic alkylation reactions of geminal dicarboxylate electrophiles typically yield branched products as the result of ipso-addition, we identify conditions wherein oxindoles react with a dipivaloyl electrophile to afford linear enol pivalate compounds. A mild hydrolysis reaction converts these products into the aldehyde that formally results from asymmetric conjugate addition to acrolein, a challenging transformation with limited literature precedent. These adducts are established precursors to tricyclic alkaloid scaffolds of pharmaceutical interest. Chiral gamma-heteroatom-substituted cycloalkenones are well-established organic "building blocks" that are widely used in the synthesis of complex molecules. The exposure of meso-1,4-allylic dibenzoates to chiral phosphine-ligated palladium salts in the presence of a potassium nitronate nucleophile promotes a unique oxidative desymmetrization reaction. This process yields enantiopure gamma-benzoyloxy cyclopentenones, cyclohexenones, and cycloheptenones. We describe the elaboration of these products into diverse, enantioenriched oxygen- and nitrogen-substituted cycloalkenones via subsequent palladium-catalyzed allylic alkylation reactions involving heteroatom nucleophiles. Separately, we employ enantiopure gamma-benzoyloxy cyclohexenones in short, asymmetric syntheses of enantio- and diastereomerically diverse epoxyquinoid natural products. We further highlight the utility of palladium catalysis in complex molecule synthesis through the development of a unique, intramolecular carbon-carbon bond-forming reaction that generates a strained enyne and through an asymmetric formal synthesis of aliskiren, a renin inhibitor used in the treatment of hypertension.

Download or read book Advances in Palladium catalyzed Carbon nitrogen Bond Forming Processes written by Rachel Elizabeth Tundel and published by . This book was released on 2006 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1. Microwave-assisted, palladium-catalyzed C-N bond-forming reactions with aryl/heteroaryl nonaflates/halides and amines using the soluble amine bases DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or MTBD (7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene) and a catalyst system consisting of Pd2dba3 and ligands (XantPhos, 2-dicylcohexylphosphino-2',4',6'-triisopropyl-1,1 '-biphenyl (XPhos) and 2-di-tert-butylphosphino-2',4',6'-triisopropyl-1, '-biphenyl) resulted in good to excellent yields of arylamines in short reaction times. Chapter 2. Using a catalyst comprised of the bulky, electron-rich monophosphine ligand di-tert-Butyl XPhos (2-di-tert-butylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl) and Pd2dba3 with sodium tert-butoxide as the base, amino heterocycles were coupled successfully with aryl/heteroaryl halides in moderate to excellent yields.

Download or read book Catalytic Methods for Carbon carbon and Carbon nitrogen Bond Formation written by Stephen David Ramgren and published by . This book was released on 2014 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the study of metal-catalyzed cross-coupling reactions to construct carbon-carbon and carbon-heteroatom bonds. The key feature of much of this work is the use of inexpensive Ni and Fe catalysts to enable the coupling of unconventional electrophilic substrates, specifically aryl O-sulfamates and O-carbamates. The ability to use O-sulfamates and O-carbamates in catalytic processes is notable, as these substrates are readily derived from phenols and can be used for directed arene functionalization. Chapter one provides a summary of the efforts towards using alcohol-based solvents for the Suzuki-Miyaura cross-coupling reaction. Emphasis is placed on the cross-coupling of heterocycles, which are commonly encountered in natural product synthesis and in the pharmaceutical sector. Chapters two, three, and four describe carbon-nitrogen bond forming reactions. Chapter two pertains to the nickel-catalyzed amination of sulfamates, which culminated in the synthesis of the antibacterial drug, linezolid. Chapter three covers the amination of aryl O-carbamates and their use in sequential functionalization/site-selective cross-couplings. Chapter four describes a more user-friendly variant of the amination reaction, which relies on a bench-stable Ni(II) precatalyst, rather than a more commonly used Ni(0) precatalyst. Chapters five, six, and seven focus on carbon-carbon bond formation via Fe-, Ni- and Pd-mediated processes. Chapter five pertains to iron-catalyzed couplings of sulfamates and carbamates to generate sp2-sp3 carbon-carbon bonds. This method can be used to assemble sterically-congested frameworks. Chapter six describes the nickel-catalyzed Suzuki-Miyaura reactions of halides and phenol derivatives in `green' solvents, which was applied to the preparative scale assembly of bis(heterocycles) using low nickel catalyst loadings. Chapter seven pertains to the acetylation of arenes using palladium catalysis, which provides a simple and efficient means for the construction of a variety of aryl methyl ketones.

Download or read book Catalyzed Carbon Heteroatom Bond Formation written by Andrei K. Yudin and published by John Wiley & Sons. This book was released on 2010-12-01 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by an experienced editor widely acclaimed within the scientific community, this book covers everything fromo9xygen to nitrogen functionalities. From the contents: Palladium-Catalyzed Syntheses of Five-Member Saturated Heterocyclic and of Aromatic Heterodynes Palladium-Catalysis for Oxidative 1, 2-Difunctionalization of Alkenes Rhodium-Catalyzed Amination of C-H-Bonds Carbon-Heteroatom Bond Formation by RH(I)-Catalyzed Ring-Opening Reactions Transition Metal-Catalyzed Synthesis of Lactones and of Monocyclic and Fused Five-Membered Aromatic heterocycles the Formation of Carbon-Sulfur and Carbon-Selenium bonds by Substitution and Addition reactions catalyzed by Transition Metal Complexes New Reactions of Copper Acetylides Gold Catalyzed Addition of Nitrogen, Sulfur and Oxygen Nucleophiles to C-C Multiple Bonds. The result is an indispensable source of information for the Strategic Planning of the Synthetic routes for organic, catalytic and medicinal chemists, as well as chemists in industry.

Download or read book Advances in Late Metal Carbon Nitrogen Bond Formation for the Synthesis of Substituted Heterocycles written by Nicolas Rotta-Loria and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Late-metal catalyzed cross-couplings have emerged as efficient and selective methodologies for the formation of C-C and C-N bonds. The ability to synthesize complex heterocycles from cheap and abundant starting materials is an invaluable asset to the pharmaceutical industry, given that many pharmaceuticals contain at least one heterocyclic component. This reactivity can be achieved by tuning the steric and electronic properties of ancillary ligands to support metal catalysts in the reaction steps leading to the target substrate. The Stradiotto group has developed several state-of-the-art methodologies involving ligands for palladium catalysis, for both C-C and C-N bond-forming reactions. These methodologies can be amalgamated into a multicomponent reaction platform to synthesize more complex products from simple materials. Chapter 1 outlines this concept with the application of a Mor-DalPhos/Pd catalyst in the one-pot synthesis of indoles from acetone and simple amines involving C-C and C-N bond formation. The robust nature of this method can be extended to include benchtop reaction conditions in a one-step, one-pot synthesis of indoles, thus representing a useful synthetic protocol. While palladium provides a powerful tool for C-C and C-N bond formation, the general trend in catalysis has shifted away from the precious metals toward first row metals as economic alternatives. Nickel complexes have recently emerged as excellent catalysts for a number of amination reactions. The ability to utilize ammonia also represents a sought after reaction, due to the widespread availability and synthetic utility of amino-functionalized products. In this regard, Chapter 2 will focus on the development and application of both commercially available and strategically designed ligand classes for the monoarylation of ammonia with substituted heterocycles. Hydrazine represents an important synthon in synthetic chemistry. It is synthesized on multi-ton scale every year and represents an important building block in many industrial processes. Many synthetic challenges arise from using free hydrazine as reactant, which has led to lethargic growth of its application in the field of late-metal catalyzed C-N bond-formation. However, gold-catalyzed methodologies have been developed utilizing NHC ligands to allow for the hydrohydrazination of alkynes with parent hydrazine. Chapter 4 examines the development and application of a series of (PR3)AuCl complexes for use in such transformations, leading to the identification of the first effective phosphine-bound gold complex for use in the hydrohydrazination of alkynes at room temperature.

Download or read book The Mizoroki Heck Reaction written by Martin Oestreich and published by John Wiley & Sons. This book was released on 2009-02-11 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the importance of Richard F. Heck’s carbon coupling reaction, this book highlights the subject of the 2010 Nobel Prize in Chemistry for palladium-catalyzed cross couplings in organic synthesis, and includes a foreword from Nobel Prize winner Richard F. Heck. The Mizoroki-Heck reaction is a palladium-catalyzed carbon–carbon bond forming process which is widely used in organic and organometallic synthesis. It has seen increasing use in the past decade as chemists look for strategies enabling the controlled construction of complex carbon skeletons. The Mizoroki-Heck Reaction is the first dedicated volume on this important reaction, including topics on: mechanisms of the Mizoroki-Heck reaction intermolecular Mizoroki-Heck reactions focus on regioselectivity and product outcome in organic synthesis waste-minimized Mizoroki-Heck reactions intramolecular Mizoroki-Heck reactions formation of heterocycles chelation-controlled Mizoroki-Heck reactions the Mizoroki-Heck reaction in domino processes oxidative heck-type reactions (Fujiwara-Moritani reactions) Mizoroki-Heck reactions with metals other than palladium ligand design for intermolecular asymmetric Mizoroki-Heck reactions intramolecular enantioselective Mizoroki-Heck reactions desymmetrizing Mizoroki-Heck reactions applications in combinatorial and solid phase syntheses, and the development of modern solvent systems and reaction techniques the asymmetric intramolecular Mizoroki-Heck reaction in natural product total synthesis Several chapters are devoted to asymmetric Heck reactions with particular focus on the construction of otherwise difficult-to-obtain sterically congested tertiary and quaternary carbons. Industrial and academic applications are highlighted in the final section. The Mizoroki-Heck Reaction will find a place on the bookshelves of any organic or organometallic chemist. “I am convinced that this book will rapidly become the most important reference text for research chemists in academia and industry who seek orientation in the rapidly growing and – for the layman – confusing field described as the “’Mizoroki–Heck reaction’.” (Synthesis, March 2010)

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 Hypervalent Iodine Chemistry written by Viktor V. Zhdankin and published by John Wiley & Sons. This book was released on 2013-10-01 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypervalent Iodine Chemistry is the first comprehensive text covering all of the main aspects of the chemistry of organic and inorganic polyvalent iodine compounds, including applications in chemical research, medicine, and industry. Providing a comprehensive overview of the preparation, properties, and synthetic applications of this important class of reagents, the text is presented in the following way: The introductory chapter provides a historical background and describes the general classification of iodine compounds, nomenclature, hypervalent bonding, structural features, and the principles of reactivity of polyvalent iodine compounds. Chapter 2 gives a detailed description of the preparative methods and structural features of all known classes of organic and inorganic derivatives of polyvalent iodine. Chapter 3, the key chapter of the book, deals with the many applications of hypervalent iodine reagents in organic synthesis. Chapter 4 describes the most recent achievements in hypervalent iodine catalysis. Chapter 5 deals with recyclable polymer-supported and nonpolymeric hypervalent iodine reagents. Chapter 6 covers the "green" reactions of hypervalent iodine reagents under solvent-free conditions or in aqueous solutions. The final chapter provides an overview of the important practical applications of polyvalent iodine compounds in medicine and industry. This book is aimed at all chemists interested in iodine compounds, including academic and industrial researchers in inorganic, organic, physical, medicinal, and biological chemistry. It will be particularly useful to synthetic organic and inorganic chemists, including graduate and advanced undergraduate students. It comprehensively covers the green chemistry aspects of hypervalent iodine chemistry, making it especially useful for industrial chemists.

Download or read book Modern Organocopper Chemistry written by Norbert Krause and published by John Wiley & Sons. This book was released on 2002 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organocopper compounds are now an integral part of every modern synthesis laboratory, allowing important stages of synthesis to be carried out in an elegant fashion. Yet a certain amount of experience is needed if they are to be used effectively. Non-experts in the field often have difficulty in choosing the most suitable reagent for a particular substrate and the prerequisites for the reaction.This manual, edited by Norbert Krause, answers such questions, since it contains all the useful tips and tricks on organocopper compounds - information gained from personal experience by the international team of authors. This allows those working in laboratories in both academia and industry to determine the optimal reagent for their needs using the substrates available for reaction and the desired products. The result is a more effective use of these synthesis tools in everyday laboratory practice.

Download or read book Reversible Oxidative Addition in Palladium Catalysis written by Stephen Newman and published by . This book was released on 2012 with total page 986 pages. Available in PDF, EPUB and Kindle. Book excerpt: