Download or read book Nickel catalyzed Asymmetric Cross couplings of Secondary Alkyl Electrophiles and Photoinduced Copper catalyzed C N Couplings written by Junwon Choi (Ph. D.) and published by . This book was released on 2014 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 describes the development of three nickel-catalyzed asymmetric Negishi cross-couplings of secondary alkyl electrophiles via a stereoconvergent process. In Section 1.1, asymmetric Negishi arylations and alkenylations of [alpha]-bromonitriles with arylzinc and alkenylzinc reagents are achieved using a nickel/bis(oxazoline) catalyst. Section 1.2 describes stereoconvergent cross-couplings of secondary unactivated alkyl electrophiles, specifically, Negishi arylations and alkenylations of [alpha]-bromosulfonamides and abromosulfones with arylzinc reagents and alkenylzirconium reagents, respectively. Section 1.3 details progress toward asymmetric cross-couplings between [alpha]-haloboronate esters and alkylzinc reagents using a nickel/diamine catalyst. Chapter 2 describes the development of photoinduced, copper-catalyzed C-N couplings between N-heterocycles and aryl halides. In particular, a variety of N-heterocycles, such as indoles, benzimidazoles, imidazoles, and carbazoles, undergo Ullmann couplings under mild conditions (room temperature) with an inexpensive catalyst (Cul, without an added ligand).

Download or read book Nickel catalyzed Cross couplings of Unactivated Secondary and Tertiary Alkyl Halides and Photoinduced Copper mediated Asymmetric C N Cross couplings written by Susan Lyn Zultanski and published by . This book was released on 2013 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 describes the development of two nickel-catalyzed Suzuki cross-coupling methodologies that employ alkyl halides as electrophiles. In Section 1.1, asymmetric [gamma]-alkylation relative to a carbonyl group is achieved via the stereoconvergent cross-coupling of racemic secondary [gamma]-chloroamides with primary alkylboranes. Section 1.2 describes the first Suzuki carbon-carbon bond-forming reaction using tertiary alkyl halides as electrophiles; specifically, unactivated tertiary alkyl bromides are cross-coupled with arylboranes. Chapter 2 describes the establishment of photoinduced asymmetric copper-mediated C-N Ullmann-type coupling processes between racemic secondary alkyl halides and N-heterocycles. Preliminary yields and enantioselectivities for a reaction between secondary benzylic halides and carbazoles, with the use of a monodentate chiral phosphine ligand, are presented. The methodology is then extended to secondary [alpha]-haloamides, including [alpha]-halolactams, which are found to afford very promising yields and enantioselectivities.

Download or read book Visible Light Photocatalysis in Organic Chemistry written by Corey R.J. Stephenson and published by John Wiley & Sons. This book was released on 2018-05-29 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling the need for a ready reference that reflects the vast developments in this field, this book presents everything from fundamentals, applications, various reaction types, and technical applications. Edited by rising stars in the scientific community, the text focuses solely on visible light photocatalysis in the context of organic chemistry. This primarily entails photoinduced electron transfer and energy transfer chemistry sensitized by polypyridyl complexes, yet also includes the use of organic dyes and heterogeneous catalysts. A valuable resource to the synthetic organic community, polymer and medicinal chemists, as well as industry professionals.

Download or read book Nickel Catalysis in Organic Synthesis written by Sensuke Ogoshi and published by John Wiley & Sons. This book was released on 2020-03-09 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference to nickel chemistry for every scientist working with organometallic catalysts Written by one of the world?s leading reseachers in the field, Nickel Catalysis in Organic Synthesis presents a comprehensive review of the high potential of modern nickel catalysis and its application in synthesis. Structured in a clear and assessible manner, the book offers a collection of various reaction types, such as cross-coupling reactions, reactions for the activation of unreactive bonds, carbon dioxide fixation, and many more. Nickel has been recognized as one of the most interesting transition metals for homogeneous catalysis. This book offers an overview to the recently developed new ligands, new reaction conditions, and new apparatus to control the reactivity of nickel catalysts, allowing scientists to apply nickel catalysts to a variety of bond-forming reactions. A must-read for anyone working with organometallic compounds and their application in organic synthesis, this important guide: -Reviews the numerous applications of nickel catalysis in synthesis -Explores the use of nickel as a relatively cheap and earth-abundant metal -Examines the versatility of nickel catalysis in reactions like cross-coupling reactions and CH activations -Offers a resource for academics and industry professionals Written for catalytic chemists, organic chemists, inorganic chemists, structural chemists, and chemists in industry, Nickel Catalysis in Organic Synthesis provides a much-needed overview of the most recent developments in modern nickel catalysis and its application in synthesis.

Download or read book Chiral Amine Synthesis written by Thomas C. Nugent and published by John Wiley & Sons. This book was released on 2010-01-14 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive presentation of this hot and important topic compiles the most up-to-date methods for chiral amine synthesis. The international list of authors reads like a "Who's Who" of the subject, providing a large array of highly practical information concentrated into the useful and essential methods. Following an introductory chapter devoted to helping readers quickly determine which strategies to choose for their investigation, this handbook and ready reference focuses on the examination of methods that are reliable and simultaneously efficient for the synthesis of structurally diverse aliphatic and aromatic chiral amines. Modern methods and applications found in (pharmaceutical) industry are also covered.

Download or read book Catalysis with Earth abundant Elements written by Uwe Schneider and published by Royal Society of Chemistry. This book was released on 2020-10-30 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Considering the limited resources of our planet, earth-abundant elements will have to be explored increasingly in the future. This book highlights the uses of the most earth-abundant elements in catalysis and will be of interest to graduates, academic researchers and practitioners in catalysis.

Download or read book Development of Stereospecific Nickel Catalyzed Cross Coupling and Reductive Cross Electrophile Coupling Reactions written by Lucas William Erickson and published by . This book was released on 2017 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the Jarvo lab has developed the field of stereospecific nickel-catalyzed cross-coupling reactions of benzylic electrophiles. This chemistry allows for straightforward synthesis of asymmetric C--C bonds. The focus of this dissertation is on the study of the mechanism of these transformations, and the development of reductive cross-electrophile coupling reactions.First, the mechanism of the nickel-catalyzed Kumada cross-coupling reaction was studied via a 13C kinetic isotope effect experiment. This experiment indicated that oxidative addition of the nickel catalyst into the C--O sigma bond was the rate limiting step. Combining this data with a rate law allowed us to propose a catalytic cycle for this reaction. Additionally, the nickel-catalyzed deoxygenation of benzylic ethers was optimized for the formation of diaryl methanes. Deoxygenation performed best with a proton-rich Grignard reagent. We demonstrated that these Grignard reagents act as the hydride source for the reduction reaction.Next, an intramolecular nickel-catalyzed reductive cross-electrophile coupling reaction of benzylic ethers and alkyl chlorides was developed. This reaction proceeds with a variety of extended aromatic and heteroaromatic groups to produce cyclopropane rings in great yields and diastereoselectivity. This is the first example of a stereospecific reductive cross-electrophile coupling reaction, as well as the first to employ alkyl ethers and alkyl halides as the electrophiles.Finally, the work on nickel-catalyzed reductive cross-electrophile coupling reactions was expanded to synthesize vinylcyclopropanes from allylic ethers and alkyl halides. This reaction occurs with both alkyl fluorides and alkyl chlorides. To the best of our knowledge, this is the first reported cross-electrophile coupling reaction of an alkyl fluoride. Ring contraction proceeds with high stereospecificity, providing selective synthesis of either diastereomer of di- and tri-substituted cyclopropanes. The utility of this methodology is demonstrated by several synthetic applications including the synthesis of the natural product dictyopterene A. 2-Vinyl-4-fluorotetrahydrofurans also undergo stereospecific ring contractions, providing access to synthetically useful hydroxymethyl cyclopropanes.

Download or read book Nickel catalyzed Asymmetric Cross couplings of Secondary Allylic Chlorides and Planar chiral Compounds in Asymmetric Synthesis written by Sunghee Son and published by . This book was released on 2008 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part I, nickel-catalyzed asymmetric carbon-carbon bond-forming reactions are described. A nickel/Pybox system effectively catalyzes regio- and enantioselective cross-couplings between racemic secondary allylic chlorides and readily available alkylzinc halides. This method is applied to generate two stereo centers in a formal total synthesis of fluvirucinine A1. In Part II, the use of planar-chiral compounds as ligands or catalysts in organic synthesis is described. A C2-symmetric planar-chiral bipyridine is an efficient ligand for copper-catalyzed asymmetric [4+1]-cycloadditions between enones and diazoacetates to form 2,3-dihydrofurans. The highly substituted dihydrofurans are not only obtained in good stereoselectivity but also readily converted to other useful molecules. This method is applied to the first catalytic enantioselective synthesis of a deoxy-C-nucleoside. The synthesis of new C2-symmetric planar-chiral catalysts is described. The diastereoslective functionalization of ferrocene using a chiral directing group enables the formation of a number of amines in enantiopure form. These catalysts are tested as several asymmetric catalysts.

Download or read book Ziegler Catalysts written by Gerhard Fink and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty years after Ziegler's discovery of the "Aufbaureaktion" and low-pressure ethene polymerization, transition metal catalyzed olefin and diolefin polymerization continues to represent one of the most active and exciting areas. Since the 1980s, outstanding scientific innovations and process improvements have revolutionized polyolefin technology and greatly simplified polymerization processes. Well-defined catalyst systems are now at hand and facilitate the understanding of basic reaction mechanisms and correlations between catalyst structures, polymer microstructures, and polymer properties. This book reviews some of the modern approaches in organometallic chemistry, Ziegler-Natta catalysis, polymerization processes, design of novel materials, and the modelling in catalyst and process development.

Download or read book Photochemically Generated Intermediates in Synthesis written by Angelo Albini and published by John Wiley & Sons. This book was released on 2013-07-01 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the latest applications of photochemistry to generate important intermediates Presenting the latest breakthroughs in the field of organic photochemistry, this book offers tested and proven photochemical approaches to synthesis, creating promising new possibilities and applications for photochemical reactions. It focuses on photoreactions involving an intermediate where mechanistic aspects control the course of the reaction and its synthetic value. Readers will discover new insights into the mechanisms and nature of photo-produced reactive intermediates for organic synthesis as well as the methods to generate them. Moreover, by focusing on highly efficient techniques for producing such species, the authors enable researchers to design and perform photoreactions within the framework of green, sustainable chemistry. Photochemically-Generated Intermediates in Synthesis begins with a discussion of the principles and practice of photo-generated intermediates. Next, the book explores: Photogeneration of carbon-centered radicals Photogeneration of heteroatom-centered radicals Photogeneration of biradicals and radical pairs Photochemical generation of radical ions Photogeneration of carbocations and carbanions Photogeneration of carbenes and nitrenes The book's final chapter is dedicated to the photochemical manipulation of intermediates. Each chapter includes key kinetic data for typical intermediates as well as detailed case examples, giving readers all the tools needed to perform their own photochemical reactions. Comparisons to non-photochemical methods are offered whenever possible. Photochemically-Generated Intermediates in Synthesis sets the stage for greater collaboration among photochemists and synthetic organic chemists, enabling these two research communities to fully leverage photochemistry in order to generate key intermediates needed for a broad range of synthetic reactions in organic chemistry.

Download or read book Cobalt Catalysis in Organic Synthesis written by Marko Hapke and published by John Wiley & Sons. This book was released on 2020-04-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a much-needed account of the formidable "cobalt rush" in organic synthesis and catalysis Over the past few decades, cobalt has turned into one of the most promising metals for use in catalytic reactions, with important applications in the efficient and selective synthesis of natural products, pharmaceuticals, and new materials. Cobalt Catalysis in Organic Synthesis: Methods and Reactions provides a unique overview of cobalt-catalysed and -mediated reactions applied in modern organic synthesis. It covers a broad range of homogeneous reactions, like cobalt-catalysed hydrogenation, hydrofunctionalization, cycloaddition reactions, C-H functionalization, as well as radical and biomimetic reactions. First comprehensive book on this rapidly evolving research area Covers a broad range of homogeneous reactions, such as C-H activation, cross-coupling, synthesis of heterocyclic compounds (Pauson-Khand), and more Chapters on low-valent cobalt complexes as catalysts in coupling reactions, and enantioselective cobalt-catalyzed transformations are also included Can be used as a supplementary reader in courses of advanced organic synthesis and organometallic chemistry Cobalt Catalysis in Organic Synthesis is an ideal book for graduates and researchers in academia and industry working in the field of synthetic organic chemistry, catalysis, organometallic chemistry, and natural product synthesis.

Download or read book Heterocycles Via Cross Dehydrogenative Coupling written by Ananya Srivastava and published by . This book was released on 2019 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the developments in the synthesis and functionalization of different heterocycles based on the formation of carbon-carbon (C-C) and carbon-heteroatom (C-X) bonds using cross-dehydrogenative coupling (CDC). Consisting of 13 chapters, the book systematically describes the advances in the synthesis and functionalization of nitrogen, oxygen, and sulfur-containing heterocycles. It also discusses the various mechanistic pathways to help readers gain an in-depth understanding of the CDC reactions of heterocycles. Lastly, in order to promote green chemistry, it addresses a range of metal-free CDC reactions of heterocycles - an area that has attracted significant attention in both academic and industrial research.

Download or read book Metal catalyzed Cross coupling Reactions written by François Diederich and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-carbon bond forming reactions are arguably the most important processes in chemistry, as they represent key steps in the building of complex molecules from simple precursors. Among these reactions, metal-catalyzed cross-coupling reactions are extensively employed in a wide range of areas of preparative organic chemistry, ranging from the synthesis of complex natural products, to supramolecular chemistry, and materials science. In this work, a dozen internationally renowned experts and leaders in the field bring the reader up to date by documenting and critically analyzing current developments and uses of metal-catalyzed cross-coupling reactions. A particularly attractive and useful feature, that enhances the practical value of this monograph, is the inclusion of key synthetic protocols, in experimental format, chosen for broad utility and application. This practice-oriented book can offer the practitioner short cuts to ensure they remain up-to-date with the latest developments.

Download or read book Ni and Fe Based Cross Coupling Reactions written by Arkaitz Correa and published by Springer. This book was released on 2016-11-26 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. 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.

Download or read book Iron Catalysis written by Bernd Plietker and published by Springer Science & Business Media. This book was released on 2011-01-05 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Juan I. Padrón and Víctor S. Martín: Catalysis by means of Fe-based Lewis acids; Hiroshi Nakazawa*, Masumi Itazaki: Fe–H Complexes in Catalysis; Kristin Schröder, Kathrin Junge, Bianca Bitterlich, and Matthias Beller: Fe-catalyzed Oxidation Reactions of Olefins, Alkanes and Alcohols: Involvement of Oxo- and Peroxo Complexes; Chi-Ming Che, Cong-Ying Zhou, Ella Lai-Ming Wong: Catalysis by Fe=X Complexes (X=NR, CR2); René Peters, Daniel F. Fischer and Sascha Jautze: Ferrocene and Half Sandwich Complexes as Catalysts with Iron Participation; Markus Jegelka, Bernd Plietker: Catalysis by Means of Complex Ferrates.

Download or read book Development of Nickel catalyzed Stereospecific Cross coupling Reactions written by Buck L. H. Taylor and published by . This book was released on 2012 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition-metal catalyzed cross-coupling reactions are powerful methods for the synthesis of natural products and medicinal compounds. Cross-coupling reactions of secondary alkyl electrophiles are currently more challenging than those of aryl or vinyl halides, but these reactions enable the construction of tertiary stereogenic centers with control of configuration. Several methods have been reported for the stereoconvergent cross-coupling of alkyl halides using chiral nickel catalysts. Herein, we report the development of a stereospecific cross-coupling reaction of enantioenriched benzylic ethers using achiral nickel catalysts. We initially performed mechanistic studies to determine the stereochemical course of established nickel-catalyzed cross-coupling reactions. A deuterium-labeled alkylborane reagent was used to establish that transmetalation from boron to nickel occurs with retention of configuration. In addition, these studies establish that alkylnickel intermediates are stereochemically stable under these cross-coupling conditions. A stereospecific cross-coupling reaction of benzylic ethers with alkyl Grignard reagents has been developed. Enantioenriched benzylic ethers, derivatives of easily synthesized chiral secondary alcohols, undergo cross-coupling with high enantiospecificity using an achiral nickel catalyst. The method was applied to the asymmetric synthesis of a biologically active diarylethane, a common structural motif in medicinally relevant compounds. Initial mechanistic studies are consistent with a rate-limiting oxidative addition that is facilitated by a magnesium Lewis-acid. The cross-coupling method has been extended to include aryl Grignard reagents for the asymmetric synthesis of triarylmethanes. The reaction proceeds in high enantiospecificity and employs an ether leaving group capable of chelating to magnesium ions. The method was applied to the asymmetric synthesis of an anti-breast-cancer agent.

Download or read book Development of Nickel catalyzed Cross electrophile Coupling of Aryl Chlorides and Triflates with Alkyl Halides written by Seoyoung Kim (Ph.D.) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cross-coupling is one of the most commonly used reactions in synthetic chemistry. While palladium-catalyzed cross-coupling is well-developed and established, cross-electrophile coupling is significantly younger field of study. In this approach two carbon electrophiles are directly coupled under reductive conditions, avoiding the need to prepare organometallic reagents. This is an attractive strategy because these reactions proceed through mild conditions, have high functional group tolerance, and employ readily available coupling partners. Nickel-catalyzed cross-electrophile couplings have seen considerable success in the past decade, initially in the coupling of organic iodides and later organic bromides. Despite these advances, the cross-coupling with the more abundant and inexpensive organic chlorides remain elusive due to their low reactivity. Furthermore the nickel-catalyzed cross-coupling of aryl triflates presents analogous challenges due to their differential reactivity. This thesis presents our studies to address these limitations. Through a combination of: (1) new ligand application, (2) fine tuning of alkyl electrophile reactivity through in situ halide exchange, (3) detailed mechanistic investigation of elementary steps, we demonstrate the nickel-catalyzed cross-electrophile coupling of these traditionally inert organic coupling partner. This dissertation is presented as follows: Chapter 1 is an introduction to cross-coupling strategies. Common palladium-catalyzed cross-coupling methods are discussed and their origin of cross-selectivity is highlighted. This is contrasted to cross-electrophile approaches of which mechanism is less well-understood. Early reports on nickel-catalyzed cross-electrophile coupling are presented and how mechanistic studies have elucidated the origin of cross-selectivity in these processes. Finally, the challenges of applying aryl chlorides in these first generation approaches are briefly discussed. Chapter 2 describes the development of nickel-catalyzed cross-electrophile coupling of aryl chlorides with primary alkyl chlorides to form C(sp2)-C(sp3) bonds. Investigation of ligands on selectivity and in situ halide exchange on the activation of C(sp3)-Cl bonds are detailed. Chapter 3 discusses a strategy for nickel-catalyzed cross-electrophile coupling of aryl triflates with alkyl halides. The development of reaction conditions for differing aryl electronics and mechanistic insights are described in detail. Mechanistically driven optimization and the extent of halide exchange to modulate alkyl halide reactivity are also discussed.