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Synthesis And Structural And Catalytic Investigation Of N Heterocyclic Carbene Metal Complexes Derived From Electron Rich Alkoxybenzimidazolin 2 Ylidenes
Download Synthesis And Structural And Catalytic Investigation Of N Heterocyclic Carbene Metal Complexes Derived From Electron Rich Alkoxybenzimidazolin 2 Ylidenes full books in PDF, epub, and Kindle. Read online Synthesis And Structural And Catalytic Investigation Of N Heterocyclic Carbene Metal Complexes Derived From Electron Rich Alkoxybenzimidazolin 2 Ylidenes ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Synthesis, and Structural and Catalytic Investigation of N-heterocyclic Carbene Metal Complexes Derived from Electron-rich Alkoxybenzimidazolin-2-ylidenes by : Peter Vernon Simpson
Download or read book Synthesis, and Structural and Catalytic Investigation of N-heterocyclic Carbene Metal Complexes Derived from Electron-rich Alkoxybenzimidazolin-2-ylidenes written by Peter Vernon Simpson and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an investigation into the synthesis, properties and application of a series of transition metal complexes bearing N-heterocyclic carbene ligands. There were four main areas of focus: the synthesis of alkoxy functionalised benzimidazolium salts and the assessment of their electron-donating abilities; the synthesis of transition metal complexes bearing electron-rich N-heterocyclic carbene ligands, and an investigation of their properties; an investigation into the catalytic activity of the palladium and rhodium complexes; and a preliminary study into the possibility of immobilising a palladium- NHC complex onto silica gel for use as a solid-supported heterogeneous catalyst. Various butoxy-functionalised benzimidazolium salts, including mono- (benzimidazolium) salts, bis(benzimidazolium) salts and benzimidazolium cyclophanes were prepared as precursors to electron rich NHC-metal complexes. Preparation of the (NHC)RhI(CO)2 complexes I - III and subsequent analysis by IR spectroscopy confirmed the increased electron richness of the butoxy-functionalised NHCs compared to the non-butoxy-functionalised analogues. Some of the benzimidazolium salts were used to prepare Ag(I)-NHC complexes for the purpose of transmetallation agents. Treatment of the Ag(I)-NHC complex IV with [RuCl2(p-cymene)]2 yielded the dinuclear cationic Ru(II)-NHC complex V, which exhibits !2-binding of the quaternary carbons of each xylyl ring to the Ru centre. This unique complex was also converted to the hexafluorophosphate complex in excellent yields. A range of Pd(II)-NHC complexes were synthesized. The complexes possessed mono(NHC), chelating bis(NHC) (bridged on one or both sides), and mixed NHC/ancillary ligand systems, in order to assess the most favourable structural characteristics of a potential catalyst. Reaction of the bis(benzimidazolium) salt VI with Pd(OAc)2 gave two complexes, VII and VIII, which were subsequently isolated. The unusual complex VII, in which the xylyl ring is folded under the metal centre, was found to isomerise to IX over approximately twenty-six days in CDCl3. The conformations of the xylyl ring in VII and IX was confirmed using selective NOESY experiments. Two trans-o-xylyl-linked Pd(II)-NHC complexes were prepared and characterised, and represent the only fully characterised complexes of this type. During efforts to synthesize the dinitrophenyl-functionalised bis(NHC)-Pd(II) complex X under strict anhydrous and anaerobic conditions, instead, the trinuclear Abstract v palladium complex XI was isolated, where one dinitrophenyl group of each ligand has been displaced, presumably by attack from adventitious water or acetate present in the reaction mixture. Pd N N N N Br. Many of the Pd(II)-NHC complexes were tested in an extensive set of experiments designed to provide an insight into favourable structural motifs for a potential catalyst and confirm the beneficial nature of the electron donating butoxy groups. It was found that the Pd(II)-NHC complexes possessing chelating bis(NHC) ligands were the most active in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions, possibly due to the robustness of these complexes at the temperatures necessary to promote the reactions. Gratifyingly, the complexes possessing butoxy groups were found to be more active than the non-butoxy-functionalised analogues.
Book Synopsis N-Heterocyclic Carbenes in Transition Metal Catalysis by : Frank Glorius
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.
Book Synopsis Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis Vol. 1 by : Steven Nolan
Download or read book Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis Vol. 1 written by Steven Nolan and published by Thieme. This book was released on 2017-06-14 with total page 807 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.
Book Synopsis Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis Vol. 2 by : Steven Nolan
Download or read book Science of Synthesis: N-Heterocyclic Carbenes in Catalytic Organic Synthesis Vol. 2 written by Steven Nolan and published by Thieme. This book was released on 2017-06-14 with total page 816 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.
Book Synopsis N-Heterocyclic Carbenes by : Silvia Diez-Gonzalez
Download or read book N-Heterocyclic Carbenes written by Silvia Diez-Gonzalez and published by Royal Society of Chemistry. This book was released on 2016-11-08 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: In less than 20 years N-heterocyclic carbenes (NHCs) have become well-established ancillary ligands for the preparation of transition metal-based catalysts. This is mainly due to the fact that NHCs tend to bind strongly to metal centres, avoiding the need of excess ligand in catalytic reactions. Also, NHC‒metal complexes are often insensitive to air and moisture, and have proven remarkably resistant to oxidation. This book showcases the wide variety of applications of NHCs in different chemistry fields beyond being simple phosphine mimics. This second edition has been updated throughout, and now includes a new chapter on NHC‒main group element complexes. It covers the synthesis of NHC ligands and their corresponding metal complexes, as well as their bonding and stereoelectronic properties and applications in catalysis. This is complemented by related topics such as organocatalysis and biologically active complexes. Written for organic and inorganic chemists, this book is ideal for postgraduates, researchers and industrialists.
Book Synopsis Synthesis of Transition Metal N-heterocyclic Carbene Complexes and Applications in Catalysis by : Michael Holtz-Mulholland
Download or read book Synthesis of Transition Metal N-heterocyclic Carbene Complexes and Applications in Catalysis written by Michael Holtz-Mulholland and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis N-Heterocyclic Carbenes in Synthesis by : Steven P. Nolan
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 2006-12-13 with total page 319 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.
Book Synopsis N-Heterocyclic Carbenes by : Steven P. Nolan
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.
Book Synopsis N-Heterocyclic Carbene-metal Complexes Derived from Imidazolium-linked Cyclophane and Biimidazolium Salts by : Valerie Jane Hesler
Download or read book N-Heterocyclic Carbene-metal Complexes Derived from Imidazolium-linked Cyclophane and Biimidazolium Salts written by Valerie Jane Hesler and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents an investigation into the synthesis of metal complexes of (Nheterocyclic carbene)-based cyclophanes. There were three main areas of focus: synthesis and complexation of bis(4,5-dihydroimidazolium) salts; the synthesis and complexation of phenol-functionalised imidazolium cyclophanes; and the synthesis and complexation of (N-heterocyclic carbene)-based cyclophanes by C-C bond activation of biimidazolium salts with electron-rich metals. The synthesis of xylyl-linked bis(4,5-dihydroimidazolium) salts was investigated. Attempts to prepare these compounds by the cyclisation of a tetraamine (linear or macrocyclic) were unsuccessful due difficulties in preparing the tetraamines. The target compounds could be prepared by adapting the methods developed for the synthesis of bis(imidazolium) salts however problems associated with purification and stability of the products prevented complexation studies. A series of phenol-, phenoxide- and anisole-functionalised imidazolium cyclophanes were prepared. Their structural properties were investigated using dynamic nmr studies and X-ray crystallography. Complexation of the functionalised cyclophanes was investigated. The phenol cyclophane I formed a dinuclear complex with mercury(II). This complex is the first example of a complex derived from a phenol-functionalised imidazolium cyclophane. However the anisole cyclophane II and the unsymmetrical phenol/ortho cyclophane III were unable to form complexes possibly due to steric hindrance and instability of the cyclophane respectively. Preliminary complexation studies of the bis(imidazolium)phenol V suggested that complexation with palladium(II) and mercury(II) were possible but more work is required to determine the optimum reaction conditions. A series of biimidazolium salts VI (both new and known) were prepared. Previously reported biimidazolium salts have very low solubility in common solvents therefore the incorporation of long alkyl chains to the bridging group was investigated as a means to improve the solubility. The structure of the salts was explored using a range of techniques including dynamic nmr spectroscopy, cyclic voltammetry, UV/Visible spectroscopy, X-ray crystallography and mass spectrometry. Some of the biimidazolium salts were able to rotate about the C2-C2' bond and the free energy of activation for this process was estimated using dynamic nmr studies. C-C bond activation of the biimidazolium salts with palladium(0) was used to form a series of palladium(II) complexes (VII) of (NHC)-based cyclophanes. These reactions are the first examples of the synthesis of bis(NHC) complexes by C-C bond activation. The reactivity of the biimidazolium salts with palladium(0) was compared to their solution structure and it was found that only the biimidazolium that were able to rotate about the C2-C2' bond could react with palladium(0).
Book Synopsis N-Heterocyclic Carbenes in Transition Metal Catalysis and Organocatalysis by : Catherine S.J. Cazin
Download or read book N-Heterocyclic Carbenes in Transition Metal Catalysis and Organocatalysis written by Catherine S.J. Cazin and published by Springer Science & Business Media. This book was released on 2010-10-04 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: N-Heterocyclic Carbenes in Transition Metal Catalysis and Organocatalysis features all catalytic reactions enabled by N-heterocyclic carbenes (NHCs), either directly as organocatalysts or as ligands for transition metal catalysts. An explosion in the use of NHCs has been reported in the literature during the past seven years making this comprehensive overview highly apropos. The book begins with an introductory overview of NHCs which could have been subtitled all you need to know about NHCs. The main body of the book is dedicated to applications of NHCs in catalysis. In addition to the success stories of NHCs in metathesis, NHCs in cross coupling and more recently NHCs in organocatalysis, all other less publicized areas are also covered. As the success of NHCs is generally attributed to their potential to stabilize metal centres, the inclusion of a chapter on the decomposition of NHC catalysts is pertinent. The book closes with a chapter describing the applications of NHCs in industrial processes, which is the first coverage of its kind, and brings a unique industrial context to this book. Included in this book: Historical aspects of NHCs Synthetic pathways to NHC precursors, free NHCs and complexes Methods of characterisation of NHCs and related complexes Electronic properties of NHCs Steric properties of NHCs and models for their description NHCs for metathesis and cross-coupling reactions NHCs as organocatalysts NHC Transition-Metal mediated oxidations, additions to multiple bonds, polymerisation and oligomerisation, cyclisations, direct arylations, reactions involving CO, C-F and C-H bond activation, ... Decomposition of NHC-containing catalysts Industrial applications involving NHC-containing catalysts N-Heterocyclic Carbenes in Transition Metal Catalysis and Organocatalysis provides a fresh view of NHCs since most contributors are young emerging researchers in the field of homogeneous catalysis using NHCs. This group of contributors is complemented by highly established academic researchers and an industrialist. This book is comprehensive, from the basic features of NHCs to the latest advances, hence it is suitable for both the novice and the expert.
Book Synopsis Advances in Metal Carbene Chemistry by : U. Schubert
Download or read book Advances in Metal Carbene Chemistry written by U. Schubert and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are only few topics in organometallic chemistry, which have stimulated research activities in as many areas, as transition-metal carbene (alkylidene) complexes. About 25 years after the first planned synthesis of a carbene complex in E.O. Fischer's laboratory in Munich the NATO Advanced Research Workshop on Transition-Metal Carbene Complexes was the first meeting which,brought together scientists from different disciplines to discuss inorganic, organic, theoretical structural catalysis-related aspects of metal carbene chemistry. The 70th birthday of Professor E.O. Fischer was a good occasion for this enterprise. The organizers of the meeting (K.D. Dotz, Marburg; F.R. KreiBl, Munchen; U. Schubert, Wurzburg) were encouraged by the fact that most of the leading scientists in this area were able to participate in the workshop. The very high standard of the contributions is reflected in this book, which contains papers from the majority of the participants. The Proceedings show the state of the art in metal carbene chemistry and will hopefully be a landmark in the development of this area of chemistry. Generous financial support for the workshop and for the preparation of this book was provided by the Scientific Affairs Division of NATO and some companies. The organizers also acknowledge the efforts of the staff of the Bildungs zentrum der Hans-Seidel-Stiftung in Wild bad Kreuth for creating a pleasant and stimulating atmosphere during the conference.
Book Synopsis Science of Synthesis N-Heterocyclic Carbenes in Catalytic Organic Synthesis by : Steven P. Nolan
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:
Book Synopsis N-Heterocyclic Carbenes in Organocatalysis by : Akkattu T. Biju
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.
Book Synopsis Synthesis and Reactivity of Metal Complexes Containing Functionalized N-heterocyclic Carbene Ligands for Catalytic Applications by : Pengfei Ai
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.
Book Synopsis N-heterocyclic Carbenes in Catalytic Organic Synthesis by : Steven Nolan
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.
Book Synopsis Exploratory Research Into Atypical N-heterocyclic Carbenes by :
Download or read book Exploratory Research Into Atypical N-heterocyclic Carbenes written by and published by . This book was released on 2013 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is to create unique and highly functional N-heterocyclic carbene complexes that provide maximum catalytic features in close proximity to the metal centers. The N-heterocyclic carbenes created over the past 20 years have generally consisted of imidazole moieties substituted at both nitrogen atoms with alkyl and aryl substitutents. These typical N-heterocylic carbenes have presented many highly stable and tunable complexes used in catalysis, however, some beneficial features would be imparted on these N-heterocyclic carbenes if one of the alkyl and aryl substituted sites were allowed to remain un-substituted. These unique atypical protic N-heterocyclic carbenes allow for acid base chemistry to occur in close proximity to the metal center while simultaneously providing the tunable, highly sigma-donating features of a typical N-heterocyclic carbene. The research presented in this thesis explores the synthetic approach to atypical protic N-heterocyclic carbene ligand precursors as well as their complexation and subsequent catalytic capabilities. Two ligand precursor families were created: one consisting of an iodobenzene moiety attached to a tert-butyl imidazole group, and one in which a pyridine ring moiety is attached to a tert-butyl imidazole group. The iodobenzene group yielded two ligand precursors, 2a and 2b, both containing methylene spacers between the auxiliary moiety and tert-butyl groups. The pyridine-containing family consisted of 3a, where the tert-butyl imidazole was directly attached to the pyridine ring, and 3c, where the tert-butyl imidazole was attached to the ring by a methylene spacer. Attempts to complex the first ligand precursor family 2a and 2b were unsuccessful and lead to the synthesis of the pyridine analogues 3a and 3c which were successfully complexed to both iridium and rhodium metal centers yielding: Ir-Phos- 3a, Ir-Phos-3c, Ir-S0-3a, Ir-S1-3c, Rh-S0-3a, and Rh-S1-3c. Catalytic studies carried out with the six complexes above consisted of the oxidation of alcohols to their corresponding ketones. These catalytic tests revealed a higher degree of successful turnover with the 3c containing complexes. Crystallographic data suggests that bond angles and bond distances found in 3c containing complexes give inherent advantages to the 3c containing complexes due to the flex allowed by the methylene spacer. Additionally, catalytic comparisons of methylated analogues of 3c with the atypical protic 3c complexes showed a decrease in catalytic activity suggesting that the presences of the un-substituted nitrogen in close proximity to the metal center yields the predicted benefit of using atypical protic N-heterocyclic carbenes.
Book Synopsis Transition Metal Complexes of N-heterocyclic Carbenes and Derivatives Thereof by : Timothy Gordon Larocque
Download or read book Transition Metal Complexes of N-heterocyclic Carbenes and Derivatives Thereof written by Timothy Gordon Larocque and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: N-heterocyclic carbenes (NHCs) have played a dominant role in organometallic chemistry for decades and revolutionized the field of homogenous catalysis. NHCs have been thoroughly studied, both experimentally and theoretically, and have shown unique reactivity towards transition metals, chalcogens, azides and pnictogens. This thesis is aimed at utilizing the unique reactivity of N-heterocyclic carbenes to develop novel, robust catalysts to mediate organic transformations. The multi-faceted work within this thesis explores the use of NHCs as ancillary ligands on early and late transition metals as potential catalysts for olefin polymerization and ring-closing metathesis, respectively. This work also includes exploring the synthesis and coordination of ancillary ligands derived from the unique reactivity of NHCs towards azides, chalcogens and pnictinidenes. The reactivity of a novel aryl-substituted acyclic imino-N-heterocyclic carbene to early transition metals, cyclooctasulfur and Grubbs-type ruthenium benzylidene complexes was explored. The reactivity of imidazol-2-imide towards Grubbs-type ruthenium benzylidene complexes and the synthesis and coordination of a novel group of ligands bearing an imidazol-2-imine scaffold were also explored. Lastly, this work will include the reactivity of IMes=PPh to Grubbs-type ruthenium benzylidene complexes.
