Download or read book Exploring Ligand Enabled Nickel Catalyzed Cross Coupling of Sulfur Based Nucleophiles written by Connor Simon and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The catalytic synthesis of C(sp2)-N linkages is of utmost significance in modern synthetic chemistry, predominantly due to their prevalence in active pharmaceutical ingredients and natural products. Pd-catalyzed cross-couplings of this type, known colloquially as Buchwald-Hartwig amination (BHA), represent a tremendously important class of reactions in research and industrial settings. The success achieved by BHA can largely be attributed to the rational design of ancillary ligands specifically configured to exploit the natural electronic characteristics of the Pd metal centre. Research efforts surrounding the BHA reaction have enabled the scope of suitable coupling partners to grow rapidly, encompassing a vast array of (hetero)aryl (pseudo)halides and NH couplings partners. Notwithstanding the value of the BHA reaction, concerns over the rising costs of Pd and subsequent sustainability issues have prompted researchers to seek economical methods for accessing these linkages. One of the most promising alternatives to Pd-catalysis is the developing field of its 3d congener, Ni. However, given the relatively underdeveloped nature of Ni-catalyzed C-N bond formation, many questions regarding the mechanistic underpinnings and scope limitations remain unanswered. In this thesis, my contributions include experimental investigations into the elementary steps of a successful Ni-catalyzed cross-coupling. The successful synthesis and characterization of primary Ni-NHR catalytic intermediates reveal previously undocumented C-N bond-forming pathways, and the implementation of the mechanistic lessons learned from these studies allow for the discovery of new ligand-enabled Ni-catalyzed C-N cross-couplings.
Download or read book Investigating the Design of Bisphosphine Ligands for Use in Nickel catalyzed C sp2 N Cross Coupling written by Jillian Clark and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Notwithstanding the matured protocol of palladium-catalyzed C(sp2)-N cross-coupling (Buchwald Hartwig Amination, BHA), the development of nickel-based catalysts that carry out analogous transformations is motivated both by the benefits of employing Earth-abundant, cost-effective first-row transition-metals, and the potential for nickel catalysts to unveil new modes of reactivity. Over the past five years, significant advances in nickel-catalyzed amination chemistry have led to a widespread interest and expansion of this methodology. Although nickel catalysts are highly effective in the cross-coupling of ammonia, alkylamine, indole, and primary amide nucleophiles with (hetero)aryl electrophiles, these catalytic systems have yet to contend with palladium analogs in terms of exceedingly low catalyst loadings and the turnover of increasingly challenging substrate classes. Whereas BHA benefits from an unambiguous set of criteria that defines optimal ancillary ligand properties for this palladium-catalyzed transformation, structure-reactivity trends for nickel counterparts are ill-defined. Additionally, complex mechanistic details exist for nickel-catalyzed C(sp2)-N cross-coupling, which may be responsible for the vague guidelines for optimizing ancillary ligands, and the need for higher catalyst loadings. My thesis work explores ancillary ligand design criteria for nickel-catalyzed C(sp2)-N cross-coupling by cross-examining top-tier bisphosphine ligand classes with aims of clarifying the apparently divergent properties that exist among state-of-the-art ancillary ligands. Information gathered from the systematic comparisons of these ligand classes results in the development of the new bisphosphine ligand, PAd2-DalPhos, which enables the hitherto unknown nickel-catalyzed C(sp2)-N cross-coupling of primary heteroarylamines with (hetero)aryl chlorides. This chemical transformation is highly sought-after by pharmaceutical chemists for the synthesis of heteroatom-dense molecular structures, and reveals a new mode of reactivity involving challenging substrates in the context of nickel catalysis.
Download or read book Cross Coupling Reactions written by Norio Miyaura and published by Springer. This book was released on 2003-07-01 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1972, a very powerful catalytic cycle for carbon-carbon bond formation was 2 first discovered by the coupling reaction of Grignard reagents at the sp -carbon. Over the past 30 years, the protocol has been substantially improved and expanded to other coupling reactions of Li,B,N,O,Al,Si,P,S,Cu,Mn,Zn,In,Sn, and Hg compounds. These reactions provided an indispensable and simple methodology for preparative organic chemists. Due to the simplicity and rel- bility in the carbon-carbon, carbon-heteroatom, and carbon-metalloid bo- formations,as well as high efficiency of the catalytic process,the reactions have been widely employed by organic chemists in various fields. Application of the protocol ranges from various syntheses of complex natural products to the preparation of biologically relevant molecules including drugs, and of sup- molecules, and to functional materials. The reactions on solid surfaces allow robot synthesis and combinatorial synthesis. Now, many organic chemists do not hesitate to use transition metal complexes for the transformation of org- ic molecules. Indeed, innumerable organic syntheses have been realized by the catalyzed reactions of transition metal complexes that are not achievable by t- ditional synthetic methods. Among these, the metal-catalyzed cross-coupling reactions have undoubtedly contributed greatly to the development of such a new area of “metal-catalyzed organic syntheses”. An excellent monograph for the cross-coupling reactions and other met- catalyzed C-C bond-forming reactions recently appeared in Metal-catalyzed Cross-coupling Reactions (Wiley-VCH,1998).
Download or read book Challenging Nickel Catalyzed Cross Couplings Enabled by Ligand Design written by Ryan McGuire and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-nitrogen linkages are highly prevalent in bioactive molecules, and as such, the development of sustainable methodologies for their formation is of immense importance to both the pharmaceutical and agricultural industries. Within this realm, the advent of homogeneous transition metal catalysis has allowed significant progress to be made in the development of routes toward the formation of these linkages, encompassing a wide range of different carbon and nitrogen-containing organic reagents. Specifically, the development of Pd-catalyzed C(sp2)-N (herein, C-N) cross-coupling (i.e. Buchwald-Hartwig-Amination, BHA) has transformed the way chemists approach solving synthetic problems. Indeed, research efforts in BHA over the past 25 years have allowed for the development of several catalytic systems, encompassing a large array of both (hetero)aryl (pseudo)halide and NH-bearing substrates. Successes in BHA can be largely attributed to the rational design of ancillary ligands, which are able to dramatically influence the reactive properties of Pd through a combination of steric and electronic effects. Despite the utility of BHA, researchers have now turned to more Earth-abundant sources for effecting these transformations, including the implementation of Cu for improved versions of well-known Ullmann-coupling, and the implementation of Ni, both as alternatives to precious Pd. In this thesis, my contributions toward the rational design, syntheses and use of appropriate ancillary ligands for enabling Ni-catalyzed C-N cross-coupling are described. Included are the development of new phosphonite/phosphine ligands such as Phen-DalPhos and related variants, along with the application of Ni-based pre-catalysts for the cross-coupling of ammonia, (hetero)anilines, indoles, sulfonamides, fluoroalkylamines and amides with (hetero)aryl (pseudo)halides under unprecedently mild conditions in Ni-based catalysis.
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 Exploring the Chemistry of Intermediates in the Nickel Catalyzed Cross coupling of Alkyl Electrophiles written by Gavin David Jones and published by . This book was released on 2007 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Nickel Catalyzed C N Cross Coupling Enabled by Tailored Ancillary Ligand Design written by Christopher Lavoie and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nickel-catalyzed Csp2-N cross-coupling of NH substrates and (hetero)aryl (pseudo)halides for the synthesis of (hetero)anilines is in the midst of a resurgence. Reactivity breakthroughs that have been achieved in this field within the past five years have served to establish Ni catalysis as being competitive with, and in some cases superior to, more well-established Pd- or Cu-based protocols. Whereas the repurposing of useful ancillary ligands from the Pd domain has been the most frequently employed approach in the quest to develop effective Ni-based catalysts for such transformations, considerable progress has been made as of late in the design of ancillary ligands tailored specifically for use with Ni. Bisphosphine ancillary ligands have proven to be well-suited for such an approach, given their modular and facile syntheses. As part of this thesis research, several new bidentate phosphine ancillary ligands were developed that are particularly effective in enabling a range of otherwise challenging Nicatalyzed Csp2-N cross-couplings. Presented herein is a comprehensive summary of my contributions to the field of Ni-catalyzed Csp2-N cross-coupling, achieved by the application of a newly developed PAd-DalPhos ancillary ligand class. It is anticipated that the discussion of key ancillary ligand design concepts and mechanistic considerations presented herein will provide a useful platform for researchers to initiate ancillary ligand design efforts for the continued development of high-performing Ni cross-coupling catalysts.
Download or read book Isoprenoid Synthesis in Plants and Microorganisms written by Thomas J. Bach and published by Springer Science & Business Media. This book was released on 2012-09-19 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Isoprenoids are important in primary and secondary metabolism. They have implications in a myriad of physiological processes notably in plants, microorganisms and parasites, and biological activities at the cellular, organism, and ecosystem levels. The importance of isoprenoids in various areas of the scientific world has spurred intense research worldwide. Also their role in "nutraceuticals" has stimulated scientific curiosity. Literature on isoprenoids is widely scattered in journals with quite differing readerships and geographic distribution. A comprehensive book on isoprenoids does not exist. Isoprenoid Synthesis in Plants and Microorganisms: New Concepts and Experimental Approaches fills this gap by presenting the latest and the most applicable information on isoprenoids. The most recent TERPNET conference serves as the backdrop and provides much of the inspiration for the topics covered in the book. Additional topics of interest are covered as well, making Isoprenoid Synthesis in Plants and Microorganisms: New Concepts and Experimental Approaches the most comprehensive review of isoprenoid synthesis to date.
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 Nickel catalyzed Cross coupling Reactions Involving Secondary and Rertiary Alkyl Nucleophiles written by Amruta Ajit Joshi and published by . This book was released on 2014 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Systematic Investigation Into Bisphosphine Ligands for Nickel Catalyzed C sp2 N Cross Coupling written by Nicole Martinek and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research into transition metal-catalyzed C-N cross-coupling reactions has been driven by a need for robust and facile synthetic routes towards bioactive molecules which are rich in C-N linkages. The use of Pd-based catalysts in Buchwald-Hartwig Amination (BHA) protocols are the most well studied and utilized within industry. The choice of Pd source, ancillary ligand, base, solvent, and the use of additives have been thoroughly investigated aiding in the selection and optimization of reaction conditions. However, research has refocused towards finding more Earth-abundant and cost-effective transition metals capable of comparable reactivity. Ni has proven to be a competitor with the development of new ancillary ligands after efforts to repurpose well-known ligands in Pd-catalysis had limited success. In particular, bisphosphines within the DalPhos ligand family have enabled the Ni-catalyzed N-arylation of challenging substrates including ammonia, alkylamines, heteroarylamines, indole, and amides with (hetero)aryl electrophiles prompting the commercialization of several ligand variants. The effects of varying experimental parameters within these ligand/Ni systems are less established and prompt further investigation in order to determine trends in reactivity and limitations. A systematic evaluation of selected bases and solvents on the effectiveness of leading DalPhos ligand variants in the C-N cross-coupling of structurally varied (hetero)aryl electrophiles with primary and secondary amines is reported herein.
Download or read book Progress in Nucleophilic Catalysis and Development of Nickel catalyzed Cross couplings of Propargylic Halides written by Sean Wesley Smith and published by . This book was released on 2009 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 describes the development of two organocatalytic processes. The first is a 13-alkylation reaction of Michael acceptors, and represents a novel umpolung process catalyzed by N-heterocyclic carbenes. The second section discusses the first successful phosphine-catalyzed, y-alkylation reaction of isomerizable allenoates. A highly enantioselective variant of this reaction is described. Chapter 2 discusses nickel-catalyzed cross-coupling reactions of secondary propargylic halides with a variety of organozinc nucleophiles. Section 2.2 describes progress toward an asymmetric alkylation reaction. In Section 2.3, the development of the first alkyl-alkyl secondary-secondary cross-coupling is described; Section 2.4 describes the application of this coupling reaction to the formal synthesis of a-cembra-2,7,1 1-triene-4,6-diol. The last section of this thesis (Section 2.5) discusses the development of the first asymmetric Negishi reaction of arylzinc reagents with secondary electrophiles.
Download or read book Applied Cross Coupling Reactions written by Yasushi Nishihara and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Applied Cross-Coupling Reactions” provides students and teachers of advanced organic chemistry with an overview of the history, mechanisms and applications of cross-coupling reactions. Since the discovery of the transition-metal-catalyzed cross-coupling reactions in 1972, numerous synthetic uses and industrial applications have been developed. The mechanistic studies of the cross-coupling reactions have disclosed that three fundamental reactions: oxidative addition, transmetalation, and reductive elimination, are involved in a catalytic cycle. Cross-coupling reactions have allowed us to produce a variety of compounds for industrial purposes, such as natural products, pharmaceuticals, liquid crystals and conjugate polymers for use in electronic devices. Indeed, the Nobel Prize for Chemistry in 2010 was awarded for work on cross-coupling reactions. In this book, the recent trends in cross-coupling reactions are also introduced from the point of view of synthesis design and catalytic activities of transition-metal catalysts.
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 Artificial Metalloenzymes and MetalloDNAzymes in Catalysis written by Montserrat Diéguez and published by John Wiley & Sons. This book was released on 2018-02-21 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: An important reference for researchers in the field of metal-enzyme hybrid catalysis Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a comprehensive review of the most current strategies, developed over recent decades, for the design, synthesis, and optimization of these hybrid catalysts as well as material about their application. The contributors—noted experts in the field—present information on the preparation, characterization, and optimization of artificial metalloenzymes in a timely and authoritative manner. The authors present a thorough examination of this interesting new platform for catalysis that combines the excellent selective recognition/binding properties of enzymes with transition metal catalysts. The text includes information on the various applications of metal-enzyme hybrid catalysts for novel reactions, offers insights into the latest advances in the field, and contains an informative perspective on the future: Explores the development of artificial metalloenzymes, the modern and strongly evolving research field on the verge of industrial application Contains a comprehensive reference to the research area of metal-enzyme hybrid catalysis that has experienced tremendous growth in recent years Includes contributions from leading researchers in the field Shows how this new catalysis combines the selective recognition/binding properties of enzymes with transition metal catalysts Written for catalytic chemists, bioinorganic chemists, biochemists, and organic chemists, Artificial Metalloenzymes and MetalloDNAzymes in Catalysis offers a unique reference to the fundamentals, concepts, applications, and the most recent developments for more efficient and sustainable synthesis.
Download or read book The Chemistry of Pincer Compounds written by David Morales-Morales and published by Elsevier. This book was released on 2011-08-11 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pincer complexes are formed by the binding of a chemical structure to a metal atom with at least one carbon-metal bond. Usually the metal atom has three bonds to a chemical backbone, enclosing the atom like a pincer. The resulting structure protects the metal atom and gives it unique properties.The last decade has witnessed the continuous growth in the development of pincer complexes. These species have passed from being curiosity compounds to chemical chameleons able to perform a wide variety of applications. Their unique metal bound structures provide some of the most active catalysts yet known for organic transformations involving the activation of bonds. The Chemistry of Pincer Compounds details use of pincer compounds including homogeneous catalysis, enantioselective organic transformations, the activation of strong bonds, the biological importance of pincer compounds as potential therapeutic or pharmaceutical agents, dendrimeric and supported materials. * Describes the chemistry and applications of this important class of organometallic and coordination compounds* Covers the areas in which pincer complexes have had an impact* Includes information on more recent and interesting pincer compounds not just those that are well-known
Download or read book Applications of Transition Metal Catalysis in Drug Discovery and Development written by Matthew L. Crawley and published by John Wiley & Sons. This book was released on 2012-05-14 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the drug discovery and development applications of transition metal catalyzed processes, which can efficiently create preclinical and clinical drug candidates as well as marketed drugs. The authors pay particular attention to the challenges of transitioning academically-developed reactions into scalable industrial processes. Additionally, the book lays the groundwork for how continued development of transition metal catalyzed processes can deliver new drug candidates. This work provides a unique perspective on the applications of transition metal catalysis in drug discovery and development – it is a guide, a historical prospective, a practical compendium, and a source of future direction for the field.
