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Book Synthesis and Structure activity Studies of Well defined Nickel Complexes as Catalysts for Cross Coupling of Alkyl Electrophiles

Download or read book Synthesis and Structure activity Studies of Well defined Nickel Complexes as Catalysts for Cross Coupling of Alkyl Electrophiles written by and published by . This book was released on 2015 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: nickel ; Kumada coupling ; Grignard reagent ; diastereoselective ; alkynylation ; Sonogashira coupling ; hemilabile ligands ; kinetics ; pincer ligands ; alkyl electrophiles.

Book Nickel Catalysis in Organic Synthesis

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.

Book Enantioselective Nickel catalysed Transformations

Download or read book Enantioselective Nickel catalysed Transformations written by Hélène Pellissier and published by Royal Society of Chemistry. This book was released on 2016 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the impressive range of uses that have been found for nickel chiral catalysts, for researchers and industrialists in organic chemistry, synthesis and medicinal chemistry.

Book Development of Nickel catalyzed Stereospecific Cross coupling Reactions

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.

Book Modern Organonickel Chemistry

Download or read book Modern Organonickel Chemistry written by Yoshinao Tamaru and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organonickel chemistry plays an increasingly important role in organic chemistry, and interest in this topic is now just as keen as in organopalladium chemistry. While there are numerous, very successful books on the latter, a book specializing in organonickel chemistry is long overdue. Edited by one of the leading experts in the field, this volume covers the many discoveries made over the past 30 years, and previously scattered throughout the literature. Active researchers working at the forefront of organonickel chemistry provide a comprehensive review of the topic, including cross-coupling reactions, asymmetric synthesis and heterogeneous catalysis reaction types. A must-have for both organometallic chemists and synthetic organic chemists.

Book Olefin Polymerization

Download or read book Olefin Polymerization written by Walter Kaminsky and published by Wiley-VCH. This book was released on 2006-08-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an enormous velocity, olefin polymerization has expanded to one of the most significant fields in polymers since the first industrial use about 50 years ago. In 2005, 100 million tons of polyolefins were produced - the biggest part was catalyzed by metallorganic compounds. The Hamburg Macromolecular Symposium 2005 with the title "Olefin Polymerization" involved topics such as new catalysts and cocatalysts, kinetics, mechanism and polymer reaction engineering, synthesis of special polymers, and characterization of polyolefins. The conference combined scientists from different disciplines to discuss latest research results of polymers and to offer each other the possibility of cooperation. This is reflected in this volume, which contains invited lectures and selected posters presented at the symposium.

Book Development of Nickel Catalyzed Coupling Reactions

Download or read book Development of Nickel Catalyzed Coupling Reactions written by Mikhail Olegovich Konev and published by . This book was released on 2017 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal catalyzed reactions are ubiquitous in the realm of synthetic chemistry, allowing for the strategic construction of complex molecular frameworks of pharmaceuticals, natural products, and synthetic materials. Palladium-catalyzed cross-coupling reactions are part of the foundation of these transformations, insofar as they were recognized with the 2010 Nobel Prize in chemistry. Traditionally, these reactions have relied on aryl and vinyl electrophiles, whereas the alkyl counterparts have only recently begun to emerge in the literature. Nickel has been on the forefront of enantioconvergent alkyl cross--coupling reactions due to its propensity to undergo single electron chemistry. However, under special conditions, it has a unique ability to break strong carbon--oxygen bonds in a stereospecific manner, making research into its reactivity a valuable endeavor to the field of organometallic chemistry.Chapter 1 describes the development of a stereospecific intramolecular alkyl-Heck cyclization of benzylic ethers. The reaction proceeds with inversion at the electrophilic carbon, for the synthesis of methylenecyclopentanes of both extended pi-electron and simple aromatic systems. The enantioenriched products can be effectively derivatized to cyclic alpha-aryl ketones in good yields with good transfer of chirality. Avenues to expand the utility of this reaction have been identified and further studies are ongoing.Chapter 2 discusses the development of nickel-catalyzed cross-electrophile coupling reactions of benzylic esters and aryl halides. An intermolecular reaction proceeds in high yields for primary benzylic esters for the synthesis of pharmacologically relevant diarylmethanes. The corresponding intramolecular cyclization proceeds under mild conditions, demonstrating the first example of a stereospecific cross-electrophile coupling of secondary benzylic esters. A variety of heterocyclic and functionalized substrates are tolerated under the reaction conditions.Chapter 3 examines the development a regio- and stereoselective nickel-catalyzed hydroarylation of alkynes with arylboronic acids. The reaction is facilitated by propargyl carbamates as directing groups. The reaction is tolerant of a range of functional groups and heterocycles. Mechanistic studies reveal that the acidic protons of the arylboronic acid coupling partner serve as the origin of hydrogen. Furthermore, the synthesis of tamoxifen can be completed in two steps from a simple hydroarylation product.

Book Applied Cross Coupling Reactions

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.

Book Development of Nickel catalyzed Cross electrophile Coupling of Aryl Chlorides and Triflates with Alkyl Halides

Download or read book Development of Nickel catalyzed Cross electrophile Coupling of Aryl Chlorides and Triflates with Alkyl Halides written by Seoyoung Kim 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.

Book Development of Stereospecific Nickel Catalyzed Cross Coupling and Reductive Cross Electrophile Coupling Reactions

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.

Book Nickel catalyzed Reductive Coupling of Aryl Halides with Alkyl Electrophiles

Download or read book Nickel catalyzed Reductive Coupling of Aryl Halides with Alkyl Electrophiles written by Lukiana L. Anka-Lufford and published by . This book was released on 2015 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The direct transition-metal catalyzed cross-coupling of two different electrophiles is a fast emerging synthetic method, as it avoids the use of carbon nucleophiles. Despite being a synthetically valuable strategy, a central challenge of cross-electrophile coupling is achieving selectivity for cross-coupled product over dimerization products. This thesis details the author's work towards the development of cross-selective methods for the formation of Csp2-Csp3 bonds. Chapter 1 introduces the conventional cross-coupling method of forming C-C bonds and highlights the advantages of using the reductive cross-electrophile coupling approach instead. The selectivity challenges associated with reductive cross-coupling and the origins of selectivity in the cross-coupling reactions of aryl halides with allylic acetates and benzyl mesylates are discussed. Motivations towards the adaptation of our cross-electrophile coupling methods to more environmentally responsible solvents and reductants are also described. Chapter 2 details a general protocol for the coupling of aryl halides with allylic acetates and shows that high cross-selectivity can be achieved with the use of a terpyridine nickel catalyst. Strength's of the method are presented such tolerance for electrophilic (ketone (71%), aldehyde (70%)) and acidic (sulfonamide (73%), trifluoroacetamide (64%)) substrates and the ability to couple with a variety of substituted allylic acetates. The reductive method addresses the regioselectivity and substrate availability limitations observed in past approaches to allylated arenes. Chapter 3 presents the first synthesis of diarylmethanes from benzyl mesylates and aryl halides using cobalt phthalocyanine (Co(Pc)), a new co-catalyst for radical generation that is compatible with nickel-catalysis. Studies are shown demonstrating the orthogonal reactivity of (dtbbpy)Ni and Co(Pc) and the application of this selectivity to the coupling of functionalized benzyl mesylates with aryl halides. The adaptation of the method to the less reactive benzyl phosphate ester and an enantioconvergent reaction are also presented. Chapter 4 shows studies towards the adaptation of cross-electrophile coupling to more environmentally friendly solvents and reductants. Here, a homogeneous, two electronic organic reductant, 1,2,2-tetrakis(dimethylamino)ethylene (TDAE), is shown to be effective for nickel-catalyzed cross-electrophile coupling in various green solvents such as propylene carbonate and acetonitrile. These reactions are close in yield to our best-reported results in amide or urea solvents using zinc or manganese as the reductant. Chapter 5 describes initial studies towards nickel-catalyzed decarbonylative coupling reactions of acid chloride derivatives with aryl and alkyl halides and nickel-catalyzed coupling reactions of aryl halides with small cyclic alkyl bromides and oxetane tosylate. Further optimization strategies are presented."--Pages viii-ix.

Book Nickel Catalyzed Cross Coupling Reactions

Download or read book Nickel Catalyzed Cross Coupling Reactions written by Luke Edward Hanna and published by . This book was released on 2016 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cross-coupling technology has become an indispensable tool for the rapid and efficient synthesis of complex molecules. Over the past few decades a foundational understanding of organometallic chemistry has been laid using palladium and other precious metals. Recent research on first row base metal catalysts such as nickel, cobalt and iron has uncovered new and complementary modes of reactivity compared to their more well-studied precious metal counterparts. While nickel sits one row above palladium on the periodic table, ongoing research has illustrated that nickel possesses a unique reactivity profile. Thus, while nickel is commonly thought of as a cheaper alternative to palladium, research in the field of nickel catalysis has demonstrated far more potential than this. The unique propensity of nickel to undergo single electron chemistry as well as its ability to break strong carbon oxygen bonds make research into nickel reactivity an immensely beneficial endeavor to the fields of inorganic, organometallic and synthetic organic chemistry.Chapter 1 describes the development of a stereospecific Suzuki coupling of benzylic carbamates and pivalates with aryl- and heteroarylboronic esters. The reaction proceeds with selective inversion or retention at the electrophilic carbon, depending on the identity of the ligand used. Tricyclohexylphosphine ligand provides products with retention of configuration at the electrophilic carbon, while an N-heterocyclic carbene ligand SIMes provides products with inversion.Chapter 2 discusses the development of a regio- and stereoselective nickel-catalyzed hydroarylation of alkynes using propargylic carbamates as directing groups. The reaction proceeds under mild reaction conditions using arylboronic acids in the absence of base. A range of heterocycles and functional groups are tolerated under the reaction conditions. Additionally, the method is applied to the synthesis of tamoxifen.Chapter 3 details a nickel-catalyzed cross-electrophile coupling reaction of benzylic esters and aryl halides. Both inter- and intramolecular variants proceed under mild reaction conditions. A range of heterocycles and functional groups are tolerated under the reaction conditions. Additionally, the first example of a stereospecific cross-electrophile coupling of a secondary benzylic ester is described.Chapter 4 presents secondary benzylzinc reagents generated from 2-pyridylcarbinols using a nickel catalyst and diethylzinc. Substrates are activated in situ using a chlorophosphate reagent. Quenching the organozinc reagents allows for facile deoxygenation of 2-pyridylcarbinols in a one-pot reaction with straightforward incorporation of a deuterium label from deuteromethanol. An intramolecular conjugate addition of a secondary benzylzinc reagent with an alpha,beta-unsaturated ester is also demonstrated.

Book Cross Coupling Reactions

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).

Book The Stille Reaction

    Book Details:
  • Author : Vittorio Farina
  • Publisher : John Wiley & Sons
  • Release : 1998-09-18
  • ISBN : 9780471312734
  • Pages : 676 pages

Download or read book The Stille Reaction written by Vittorio Farina and published by John Wiley & Sons. This book was released on 1998-09-18 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Die Stille-Reaktion ist eine der sehr wenigen Reaktionen, in denen unter milden Bedingungen Kohlenstoff-Kohlenstoff-Bindungen geknüpft werden können. Man verwendet die Reaktion häufig in der Synthese komplizierter Moleküle zur Verknüpfung größerer Molekülbausteine. Die Autoren diskutieren vom präparativen Standpunkt aus Grenzen, Einflüsse, strukturelle Effekte und die Wahl der geeigneten Reaktionsbedingungen. Mit ausführlichen Vorschriften und vielen Beispielen. (11/98)

Book Organozinc Derivatives and Transition Metal Catalysts

Download or read book Organozinc Derivatives and Transition Metal Catalysts written by Janine Cossy and published by Walter de Gruyter GmbH & Co KG. This book was released on 2023-05-22 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organozinc reagents are less reactive than Grignard reagents but they are much more chemoselective. Since the Negishi cross-coupling reaction developed by Ei-ichi Negishi, who was awarded the Nobel Price in chemistry in 2010, a number of cross-coupling reactions involving organozinc derivatives and transition metal catalysts (Pd, Ni, Fe, Co, Cu, ...) has been tuned up to form C-C bonds. This book on "Organozinc derivatives and transition metal catalysts" has been written by experts in the field and is a complement to the book entitled "Grignard reagents and transition metal catalysts" (a De Gruyter book, edited by J. Cossy). Grignard reagents or organozinc reagents, that is the question? From a given substrate, what is the best organometallic reagent and the best transition metal to form a C-C bond by using a cross-coupling reaction? The solution might be found in these two books.

Book Nickel catalyzed Electrophile Cross coupling of Aryl Halides with Alkyl Halides

Download or read book Nickel catalyzed Electrophile Cross coupling of Aryl Halides with Alkyl Halides written by Daniel A. Everson and published by . This book was released on 2013 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis details the author's contributions to the emerging field of electrophile cross-couplings. This new field is related to the well-established field of conventional cross-coupling that uses transition metal-catalysts to facilitate coupling reactions between electrophile-nucleophile pairs. Electrophile cross-coupling uses a conceptually different approach because it seeks to selectively join two different electrophiles with a transition metal-catalyst. The issue of developing cross-selective reactions is the central challenge addressed. Chapter 1 details recent advances and the state-of-the-art in conventional cross-coupling only for the purpose of conceptual comparison to electrophile cross-coupling. Additionally, a review of similar coupling reactions and their mechanisms are presented with the earliest examples of the unique reactivity that guided development of the reactions in this thesis. Chapter 2 details the first cross-selective nickel-catalyzed electrophile cross-coupling of iodoarenes with iodoalkanes. The new method displays exceptional functional group compatibility (-C(O)Me, -NHBoc, 1° and 2° alkyls, -OH) and the catalyst shows chemoselective reaction at C-I bonds over C-B bonds on bifunctional substrates. Mechanistic studies reveal that the reaction likely proceeds without the intermediacy of a carbon nucleophile, and that dimeric by-products arise from disproportionation of nickel intermediates. Chapter 2 also summarizes a detailed mechanistic study conducted in our lab that indicates the cross-coupled product is formed by a radical chain mechanism. Chapter 3 expands on the results of Chapter 2 by increasing the scope of the method to include bromo- and chloroarenes for the first time. Additional competition experiments reveal that the new catalysts and reaction conditions are chemoselective for the cross-coupling of two electrophilic C-Br bonds over conventional cross coupling of C-Br bonds with C-B, C-Sn, or C-Si bonds. Further mechanistic work reveals that [upsilon] [is proportional to] [bromoalkane][^x][catalyst][^y]/[bromoarene][^z] (x, y, and z are positive numbers and could be non-integers). Chapter 4 presents the first electrophile cross-couplings of halogenated pyridines with alkyl bromides. Scope and limitations are discussed in the context of improving the method. Chapter 5 details the effect of additives on other related electrophile coupling reactions"--Pages vii-viii.

Book Pincer and Pincer Type Complexes

Download or read book Pincer and Pincer Type Complexes written by Kálmán J. Szabó and published by John Wiley & Sons. This book was released on 2014-06-10 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new book on this hot topic summarizes the key achievements for the synthesis and catalytic applications of pincer and pincer-type complexes, providing readers with the latest research highlights. The editors have assembled an international team of leaders in the field, and their contributions focus on the application of various pincer complexes in modern organic synthesis and catalysis, such as C-C and C-X bond forming reactions, C-H bond functionalization, and the activation of small molecules, as well as asymmetric catalysis. A must-have for every synthetic chemist in both academia and industry intending to develop new catalysts and improved synthetic protocols.