Download or read book Synthesis of Bifunctional Pincer Metal Complexes Containing N heterocyclic Carbenes written by Derek B. Brown and published by . This book was released on 2010 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research is to synthesize pincer ligands and complexes with a central pyridine ligand substituted at positions 2 and 6 by two N-heterocyclic carbenes, each bearing a pendant heteroaryl substituent. Related pincers without heteroaryl groups have been reported in the past 15 years as catalysts, and our ultimate goal was to enable the study of the heteroaryl moieties as pendant bases, creating improved bifunctional catalysts. Two classes of pincers were made: one with methylene spacers between the central pyridine and the imidazol-2-ylidene groups, and those whose imidazol-2-ylidene groups were attached directly to the pyridine without any spacers. Four bis(imidazolium) salt pincer precursors with methylene spacers were made, and reaction with Ag2O produced silver-carbene complexes which act as transmetallation agents for further complexation. Two of the analogs were able to be metallated with (COD)PdCl2 to form palladium-carbene complexes, NMR data for which are in accord with a puckered structure induced by the methylene spacers. One of these complexes showed catalytic activity in the Heck coupling reaction. Synthesis of analogs lacking spacers under literature conditions proved to be impossible, presumably because of reduced nucleophilicity of 1-heteroarylimidazoles. Thus, a systematic study of reactivity of 1-substituted imidazoles with five 2,6-disubstituted pyridines conclusively showed that 2,6-bis(trifluoromethanesulfonyloxy)pyridine (16) was the best precursor. A well-described synthesis of 16 was developed, paving the way to making seven analogs of pincer precursors without methylene spacers. Reaction of two of these pincer precursors with Ag2O and NaOH produced silver-carbene bridged-dimer complexes which were characterized by X-ray diffraction and show promise as sources of other metal complexes.
Download or read book N heterocyclic Carbenes written by Silvia Díez-González and published by Royal Society of Chemistry. This book was released on 2011 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last fifteen years, N-heterocyclic carbenes (NHCs) have mostly been used as ancillary ligands for the preparation of transition metal-based catalysts. Compared to phosphorus-containing ligands, NHCs tend to bind more strongly to metal centres, avoiding the necessity for the use of excess ligand in catalytic reactions. The corresponding complexes are often less sensitive to air and moisture, and have proven remarkably resistant to oxidation. Recent developments in catalysis applications have been facilitated by the availability of carbenes stable enough to be bottled, particularly for their use as organocatalysts. This book shows how N-heterocyclic carbenes can be useful in various fields of chemistry and not merely laboratory curiosities or simple phosphine mimics. NHCs are best known for their contribution to ruthenium and palladium-catalysed reactions but the scope of this book is much broader. The synthesis of NHC ligands and their corresponding metal complexes are covered in depth. Moreover, the biological activity of NHC-containing complexes, as well as an overview of their theoretical aspects are included. Such metal species are further examined, not only in terms of their catalytic applications, but also of their stereoelectronic parameters and reactivity/stability. Finally, special attention is given to the hot topic of organocatalysis. The book will be of interest to postgraduates, academic researchers and those working in industry.
Download or read book N Heterocyclic Carbenes in Synthesis written by Steven P. Nolan and published by John Wiley & Sons. This book was released on 2006-10-27 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first handbook to focus solely on the application of N-heterocyclic carbenes in synthesis covers metathesis, organocatalysis, oxidation and asymmetric reactions, along with experimental procedures. Written by leading international experts this is a valuable and practical source for every organic chemist.
Download or read book N Heterocyclic Carbenes written by Steven P. Nolan and published by John Wiley & Sons. This book was released on 2014-07-07 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive reference and handbook covers in depth all major aspects of the use of N-heterocyclic carbene-complexes in organic synthesis: from the theoretical background to characterization, and from cross-coupling reactions to olefin metathesis. Edited by a leader and experienced scientist in the field of homogeneous catalysis and use of NHCs, this is an essential tool for every academic and industrial synthetic chemist.
Download or read book Synthesis and Reactivity of Metal Complexes Containing Functionalized N heterocyclic Carbene Ligands for Catalytic Applications written by Pengfei Ai and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this work was the synthesis of N,N'-diphosphanyl-functionalized NHC ligands andtheir coordination chemistry. The novel stable and rigid tridentate N,N'-diphosphanyl-imidazol-2-ylidene was synthesized and experimental and computational information on its stability weregained. It served as a unique platform for the synthesis of novel mono-, di-, tri-, penta-, hexanuclear complexes with the coinage metals (Cu, Ag and Au), exhibiting rare structural features. The mono- and dinuclear complexes with one or two dangling P-donors provided rational access to heterotrinuclear complexes. All these coinage metal complexes have short metal-metalseparations, indicating the presence of d10-d10 interactions, and display excellent luminescentproperties. Partial or complete transmetallation of the homotrinuclear Cu or Ag complexes withPd(0) precursors led to hetero-trinuclear complexes with d10-d10 interactions. In addition to itsbridging behavior, this ligand also showed its chelating behavior in Pd or Cr(III) complexes. Thelatter displayed superior performance in ethylene oligomerization than the Cr(II) complexes andgave mostly oligomers.
Download or read book The Organometallic Chemistry of N heterocyclic Carbenes written by Han Vinh Huynh and published by John Wiley & Sons. This book was released on 2017-02-03 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Organometallic Chemistry of N-heterocyclic Carbenes describes various aspects of N-heterocyclic Carbenes (NHCs) and their transition metal complexes at an entry level suitable for advanced undergraduate students and above. The book starts with a historical overview on the quest for carbenes and their complexes. Subsequently, unique properties, reactivities and nomenclature of the four classical NHCs derived from imidazoline, imidazole, benzimidazole and 1,2,4-triazole are elaborated. General and historically relevant synthetic aspects for NHCs, their precursors and complexes are then explained. The book continues with coverage on the preparation and characteristics of selected NHC complexes containing the most common metals in this area, i.e. Ni, Pd, Pt, Ag, Cu, Au, Ru, Rh and Ir. The book concludes with an overview and outlook on the development of various non-classical NHCs beyond the four classical types. Topics covered include: Stabilization, dimerization and decomposition of NHCs Stereoelectronic properties of NHCs and their evaluation Diversity of NHCs Isomers of NHC complexes and their identification NMR spectroscopic signatures of NHC complexes normal, abnormal and mesoionic NHCs The Organometallic Chemistry of N-heterocyclic Carbenes is an essential resource for all students and researchers interested in this increasingly important and popular field of research.
Download or read book N Heterocyclic Carbenes in Transition Metal Catalysis written by Frank Glorius and published by Springer Science & Business Media. This book was released on 2007 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book leading experts have surveyed major areas of application of NHC metal complexes in catalysis. The authors have placed a special focus on nickel- and palladium-catalyzed reactions, on applications in metathesis reactions, on oxidation reactions and on the use of chiral NHC-based catalysts. This compilation is rounded out by an introductory chapter and a chapter dealing with synthetic routes to NHC metal complexes.
Download or read book Organometallic Pincer Chemistry written by Gerard van Koten and published by Springer. This book was released on 2012-09-17 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gerard van Koten: The Mono-anionic ECE-Pincer Ligand - a Versatile Privileged Ligand Platform: General Considerations.- Elena Poverenov, David Milstein: Non-Innocent Behavior of PCP and PCN Pincer Ligands of Late Metal Complexes.- Dean M. Roddick: Tuning of PCP Pincer Ligand Electronic and Steric Properties.- Gemma R. Freeman, J. A. Gareth Williams: Metal Complexes of Pincer Ligands: Excited States, Photochemistry, and Luminescence.- Davit Zargarian, Annie Castonguay, Denis M. Spasyuk: ECE-Type Pincer Complexes of Nickel.- Roman Jambor and Libor Dostál: The Chemistry of Pincer Complexes of 13 - 15 Main Group Elements.- Kálmán J. Szabo: Pincer Complexes as Catalysts in Organic Chemistry.- Jun-ichi Ito and Hisao Nishiyama: Optically Active Bis(oxazolinyl)phenyl Metal Complexes as Multi-potent Catalysts.- Anthony St. John, Karen I. Goldberg, and D. Michael Heinekey: Pincer Complexes as Catalysts for Amine Borane Dehydrogenation.- Dmitri Gelman and Ronit Romm: PC(sp3)P Transition Metal Pincer Complexes: Properties and Catalytic Applications.- Jennifer Hawk and Steve Craig: Physical Applications of Pincer Complexes.
Download or read book Hydrogen Transfer Reactions written by Gabriela Guillena and published by Springer. This book was released on 2016-09-27 with total page 393 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 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 Novel Metal Complexes of Bifunctional Imidazolyl substituted N heterocyclic Carbenes and Catalytic Applications written by Hai Ngan Tran and published by . This book was released on 2011 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bifunctional organometallic catalysts offer unique opportunities for new and improved reactivity and selectivity. The combination of a metal's d electrons and a pendant base or acid in the vicinity of an organometallic active site leads to substantial improvement of reaction rate in many key reactions. Here we report a synthesis of the first example of an imidazol-2-yl substituted bifunctional N-heterocyclic carbene ligand (NHC) and its coordination to a variety of metals. The metal complexes have been characterized by IR, NMR, and X-ray crystallography. The catalytic activity of these new NHC-metal complexes in hydrogenation reactions (e.g. Oppenauer-type alcohol oxidation, ß-alkylation of secondary alcohols with primary alcohols, N-alkylation of amines with alcohols), hydroamination, and azide-alkyne cycloaddition reactions is described.
Download or read book Synthesis Toward N heterocyclic Carbene Diarylthiolate Pincer Ligands and Their Transition Metal Complexes written by Ryan Cheng and published by . This book was released on 2011 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book N heterocyclic Carbenes in Catalytic Organic Synthesis written by Steven Nolan and published by Thieme Chemistry. This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of N-heterocyclic carbenes, whether in transition-metal catalysis or organocatalysis, is rapidly evolving towards applications, but is also still very active on the catalyst development front. Significant advances have been made over the past two decades and the development of these reactions has dramatically improved the efficiency of organic synthesis. N-Heterocyclic carbene based catalysts are now widely applied in the area of synthesis of both natural products and therapeutic agents. Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis presents the most commonly used and significant metal- or non-metal-catalyzed reactions for modern organic synthesis. The basic principles and current state-of-the-art of the methods are covered. Scope, limitations, and mechanism of these reactions are discussed and key experimental procedures are included. Typical examples of target synthesis are often provided to show the utility and inspire further applications.
Download or read book Studies on Bis Protic N Heterocylic Carbene Pincer Complexes and on Water Oxidation Catalysts written by David Charles Marelius and published by . This book was released on 2015 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science of Synthesis N Heterocyclic Carbenes in Catalytic Organic Synthesis written by Steven P. Nolan and published by . This book was released on 2016-12 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book N Heterocyclic Carbenes in Organocatalysis written by Akkattu T. Biju and published by John Wiley & Sons. This book was released on 2019-03-04 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizing the emerging field of N-heterocyclic carbenes used in organocatalysis, this is an excellent overview of the synthesis and applications of NHCs focusing on carbon-carbon and carbon-heteroatom bond formation. Alongside comprehensive coverage of the synthesis, characteristics and applications, this handbook and ready reference also includes chapters on NHCs for polymerization reactions and natural product synthesis.
Download or read book N heterocyclic Carbene Palladium Pincer Complexes written by Jagadeesh Malineni and published by . This book was released on 2011 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
