Download or read book Catalytic C H Bond Functionalization Reactions Catalyzed by Rhodium iii Porphyrin Palladium ii and Platinum ii Acetate Complexes written by Hung-Yat Thu and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Catalytic C H Bond Functionalization Reactions Catalyzed by Rhodium III Porphyrin Palladium II and Platinum II Acetate Complexes written by Hung-yat Thu and published by . This book was released on 2006 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Strategies for Palladium Catalyzed Non directed and Directed C bond H Bond Functionalization written by Anant R. Kapdi and published by Elsevier. This book was released on 2017-05-23 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strategies for Palladium-Catalyzed Non-directed and Directed C-H Bond Functionalization portrays the complete scope of these two aspects of C-H bond functionalization in a single volume for the first time. Featured topics include the influence of palladacyclic systems in C-H bond functionalization (need for newer catalytic systems for better efficiency), mechanistic aspect of the functionalization strategies leading to better systems, and applications of these methodologies to natural product synthesis and material synthesis. Addresses the involvement of catalytic systems (palladacycles) for better functionalization of (hetero)arenes to emphasize the need for developing better, more selective systems Covers the use of powerful mechanistic tools for understanding and assisting the development of better functionalization strategies Discusses the finer aspects of C-H bond functionalization, such as control of regioselectivity with or without directing groups Includes a chapter detailing the synthesis of naturally occurring molecules or functional molecules via both pathways for assessing the applicability of the functionalization strategies

Download or read book Higher Oxidation State Organopalladium and Platinum Chemistry written by Allan J. Canty and published by Springer. This book was released on 2011-02-25 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kyle A. Grice, Margaret L. Scheuermann and Karen I. Goldberg: Five-Coordinate Platinum(IV) Complexes.- Jay A. Labinger and John E. Bercaw: The Role of Higher Oxidation State Species in Platinum-Mediated C-H Bond Activation and Functionalization.- Joy M. Racowski and Melanie S. Sanford: Carbon-Heteroatom Bond-Forming Reductive Elimination from Palladium(IV) Complexes.- Helena C. Malinakova: Palladium(IV) Complexes as Intermediates in Catalytic and Stoichiometric Cascade Sequences Providing Complex Carbocycles and Heterocycles.- Allan J. Canty and Manab Sharma: h1-Alkynyl Chemistry for the Higher Oxidation States of Palladium and Platinum.- David C. Powers and Tobias Ritter: Palladium(III) in Synthesis and Catalysis.- Marc-Etienne Moret: Organometallic Platinum(II) and Palladium(II) Complexes as Donor Ligands for Lewis-Acidic d10 and s2 Centers.

Download or read book Weak Coordination as a Powerful Means for Developing Useful Palladium II catalyzed C H Activation Reactions written by Tian-Sheng Mei and published by . This book was released on 2011 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt: Achieving direct and selective functionalization of carbon-hydrogen (C-H) bonds to give carbon-carbon (C-C) or carbon-heteroatom (C-Y) bonds is a significant and long-standing goal in chemistry. C-H bonds are attractive reaction partners because they are ubiquitous in organic molecules. Thus, C-H functionalization methods could potentially expedite the synthesis of target molecules by providing new disconnections in retrosynthetic analysis. Among the numerous methods to affect this transformation, palladium-catalyzed C-H functionalization is one of most promising methods to construct C-C and C-Y bonds in term of versatile reactivity. The major challenges of palladium-catalyzed C-H functionalization are developing reactions that work with common and useful structural motifs and discovering new transformation, such as C-N or C-F bond formation. This thesis explores palladium-catalyzed C-H bond functionalization with substrates containing simple functional groups such as carboxylic acids and triflamides, which direct C-H cleavage through weak coordination with the metal catalyst. Chapter one introduces different types of C-H bond functionalization and focuses on Pd(II)/Pd(IV) catalysis. Chapter two covers Pd-catalyzed C-H iodination of arene carboxylic acids enabled by the discovery of coutercation-promoted C-H activation. Weak coordination has also been found to enable versatile reactivity of simple arene carboxylic acids. Chapter three focuses on the development of practical and useful C-H fluorination using triflamide as a weakly coordinating directing group that can be easily manipulated to a wide range of useful and common aryl halides. Chapter four describes applications of bystanding F+ oxidants to promote selective C-N reductive elimination in Pd(II)/Pd(IV) catalysis.

Download or read book The Mizoroki Heck Reaction written by Martin Oestreich and published by John Wiley & Sons. This book was released on 2009-02-11 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the importance of Richard F. Heck’s carbon coupling reaction, this book highlights the subject of the 2010 Nobel Prize in Chemistry for palladium-catalyzed cross couplings in organic synthesis, and includes a foreword from Nobel Prize winner Richard F. Heck. The Mizoroki-Heck reaction is a palladium-catalyzed carbon–carbon bond forming process which is widely used in organic and organometallic synthesis. It has seen increasing use in the past decade as chemists look for strategies enabling the controlled construction of complex carbon skeletons. The Mizoroki-Heck Reaction is the first dedicated volume on this important reaction, including topics on: mechanisms of the Mizoroki-Heck reaction intermolecular Mizoroki-Heck reactions focus on regioselectivity and product outcome in organic synthesis waste-minimized Mizoroki-Heck reactions intramolecular Mizoroki-Heck reactions formation of heterocycles chelation-controlled Mizoroki-Heck reactions the Mizoroki-Heck reaction in domino processes oxidative heck-type reactions (Fujiwara-Moritani reactions) Mizoroki-Heck reactions with metals other than palladium ligand design for intermolecular asymmetric Mizoroki-Heck reactions intramolecular enantioselective Mizoroki-Heck reactions desymmetrizing Mizoroki-Heck reactions applications in combinatorial and solid phase syntheses, and the development of modern solvent systems and reaction techniques the asymmetric intramolecular Mizoroki-Heck reaction in natural product total synthesis Several chapters are devoted to asymmetric Heck reactions with particular focus on the construction of otherwise difficult-to-obtain sterically congested tertiary and quaternary carbons. Industrial and academic applications are highlighted in the final section. The Mizoroki-Heck Reaction will find a place on the bookshelves of any organic or organometallic chemist. “I am convinced that this book will rapidly become the most important reference text for research chemists in academia and industry who seek orientation in the rapidly growing and – for the layman – confusing field described as the “’Mizoroki–Heck reaction’.” (Synthesis, March 2010)

Download or read book Organotransition Metal Chemistry From Bonding to Catalysis written by John F. Hartwig and published by . This book was released on 2010-02-10 with total page 1172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on Collman et al.'s best-selling classic book, Principles and Applications of Organotransition Metal Chemistry, Hartwig's text consists of new or thoroughly updated and restructured chapters and provides an in-depth view into mechanism, reaction scope, and applications. It covers the most important developments in the field over the last twenty years with great clarity with a selective, but thorough and authoritative coverage of the fundamentals of organometallic chemistry, the elementary reactions of these complexes, and many catalytic processes occurring through organometallic intermediates, making this the Organotransition Metal Chemistry text for a new generation of scientists.

Download or read book Part A written by David Lapointe and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book C X Bond Formation written by Arkadi Vigalok and published by Springer. This book was released on 2010-06-30 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Kilian Muñiz: Transition Metal Catalyzed Electrophilic Halogenation of C-H bonds in alpha-Position to Carbonyl Groups; Arkadi Vigalok * and Ariela W Kaspi: Late Transition Metal-Mediated Formation of Carbon-Halogen Bonds; Paul Bichler and Jennifer A. Love*: Organometallic Approaches to Carbon-Sulfur Bond Formation; David S. Glueck: Recent Advances in Metal-Catalyzed C-P Bond Formation; Andrei N. Vedernikov: C-O Reductive Elimination from High Valent Pt and Pd Centers; Lukas Hintermann: Recent Developments in Metal-Catalyzed Additions of Oxygen Nucleophiles to Alkenes and Alkynes; Moris S. Eisen: Catalytic C-N, C-O and C-S bond formation promoted by organoactinide complexes.

Download or read book Activation and Functionalization of C H Bonds written by Karen I. Goldberg and published by ACS Symposium. This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Activation and Functionalization of C-H Bonds explores recent developments in the reaction chemistry of solution-phase transition-metal based systems with simple hydrocarbons and with more complex organic molecules. More than 20 internationally leading research groups contributed to this volume, and their chapters cover such topics as fundamental theoretical and mechanistic studies of C-H bond activation by metal complexes, catalytic systems for alkane functionalization, and new applications in synthetic organic chemistry. An introductory chapter offers an overview of stoichiometric and catalytic reactions of C-H bonds with transition metal complexes. The C-H bond is the most widespread linkage in organic chemistry, present in virtually every organic molecule. Unfortunately, C-H bonds are famously resistant to selective chemical transformations. The development of methods for their selective transformations has enormous potential value in fields ranging from the chemistry of fuels (for example, the conversion of methane to methanol) to the synthesis of the most complex organic molecules.

Download or read book Rhodium Porphyrin Alkylations with Ammonium and Quinolinium Salts and Cyclic Ether Formation Via a Palladium Catalyzed Dehydrogenative Annulation written by Samuel John Thompson and published by . This book was released on 2016 with total page 1304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation and study of metal–carbon [greek small letter sigma]-bonds can help unveil unique reactivities of organometallic complexes and provide support for further catalytic transformations. Rhodium porphyrins have shown exceptional reactivity through radical- type transformations, attracting significant attention towards understanding these metalloradical-mediated mechanisms. The stability and selectivity of rhodium porphyrins are promising for catalytic transformations, however, strong rhodium–carbon bonds frequently limit catalyst turnover. To gain a better understanding of Rh–C bonds in the porphyrin system, the synthesis of alkyl rhodium porphyrins through a C–N bond dealkylation of ammonium and quinolinium salts was conducted. The organometallic complexes were formed under air and with water, serving as a convenient method to prepare Rh–C bonds. Mechanistic studies support rhodium(I), rhodium(II), and rhodium(III) porphyrin intermediates operating in the alkylation, with a SN2-like reaction in the Rh–C bond forming step. A directed sp3 C–H bond functionalization strategy was also investigated to accomplish cyclic ether formation via an intramolecular alkoxylation reaction. An oxime vii directing group provided chemoselective activation at [greek small letter beta]-methyl positions, forming annulated products from the addition of tethered alcohol nucleophiles. Four- to seven- membered rings could be accessed through this dehydrogenative annulation pathway. Tethered primary, secondary, and tertiary free hydroxyl groups can all react to give the corresponding cyclized products. Protected silyl and benzyl alcohols were also compatible nucleophiles for the coupling. Preliminary mechanistic analysis supports an sp3 C–H activation/intramolecular SN2 pathway.

Download or read book Palladium catalyzed C H Bond Functionalization of Heterocycles and Amines written by Enrico Tapire Nadres and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Palladium-catalyzed functionalization of C-H bonds is becoming an important synthetic tool that allows the preparation of desired substances in fewer steps and higher yields compared to traditional synthetic routes. The C-H bonds can be directly converted to C-C or C-heteroatom bonds. However, the ubiquity of C-H bonds in organic compounds can lead to problems in chemo- and regioselectivity. In heterocycles, the control of regioselectivity of the reaction is governed by the difference in acidity of the heterocyclic ring C-H bonds. An economical method for the arylation of C-H bonds of pyrroles and furans by aryl chlorides was developed. The method employs a palladium acetate catalyst, 2-(dicyclohexylphosphino)biphenyl ligand, and an inorganic base. Electron-rich, electron-poor, and heterocyclic aryl chloride coupling partners can be used and arylated heterocycles are obtained in moderate to good yields. The functionalization of sp2 and sp3 C-H bonds can be promoted by the use of directing groups that coordinate the Pd catalyst and activate the desired C-H functionalities. Use of Pd(OAc)2 in conjunction with cesium acetate or potassium carbonate bases allows functionalization of sp2 and sp3 C-H bonds in amides possessing picolinic acid directing group. Stoichiometric silver additive is not required in contrast with previously published procedure. Arylations are effective for sp2 as well as primary and secondary sp3 C-H bonds. Alkylations of sp2 C-H bonds are successful in most cases. Both primary and secondary alkyl iodides are reactive but secondary alkyl iodides afford low yields. Alkylation of sp2 C-H bonds is low yielding and the reaction requires further optimization. Alkyl and aryl iodides as well as benzyl bromides are reactive. Aryl and alkyl bromides afford no product. Direct conversion of C-H bonds to C-N bonds was also developed. Pd-catalyzed method for pyrrolidine, indoline, and isoindoline formation by cyclization via C-H/N-H coupling is presented. The method employs a picolinamide directing group, PhI(OAc)2 oxidant, and toluene solvent at 80-120 °C. Cyclization is effective for sp2 as well as aliphatic and benzylic sp3 C-H bonds.

Download or read book C C Bond Activation written by Guangbin Dong and published by Springer. This book was released on 2014-09-18 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry presents critical reviews of the present and future trends in modern chemical research. 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. Review articles for the individual volumes are invited by the volume editors. Readership: research chemists at universities or in industry, graduate students

Download or read book Reactivity of Rhodium heteroatom Bonds from Catalytic Bond Activation to New Strategies for Olefin Functionalization written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rhodium complexes bearing multidentate nitrogen donor ligands were investigated for their ability to promote alkyne and olefin functionalization reactions. This thesis work is comprised of two projects in which rhodium-heteroatom reactivity is investigated: P-H bond activation reactions and olefin functionalizations via rhodaoxetane intermediates. [Tp*Rh(PPh3)2] [Tp* = hydrotris(3,5-dimethylpyrazolyl)borate] and [Tp*Rh(cod)]2 (cod = cyclooctadiene) were evaluated for their activity in alkyne hydrophosphinylation in comparison to known catalysts for this reaction. [Tp*Rh(PPh3)2]and [Tp*Rh(cod)]2 were both shown to effect hydrophosphinylation of 1-octyne with diphenylphosphine oxide with high regioselectivity but moderate yields in comparison with Wilkinson's catalyst [C1Rh(PPh3)3]. [Tp*Rh(PPh3)2] was further shown to effect hydrophosphinylation of a range of aromatic and aliphatic alkynes with diphenylphosphine oxide, in each case exclusively providing the E-linear vinylphosphineoxide product. 1H and 31P NMR spectroscopy provided evidence that alkyne hydrophosphinylation in the presence of pyrazolylborate rhodium complexes follows an analogous mechanism to that proposed for this reaction catalyzed by [C1Rh(PPh3)3] or[C1Rh(cod)]2. The 2-rhodaoxetane [(TPA)Rhmec2_, -4u, 0-2-oxyethypr BPh4- (TPA = tris[(2-pyridal)methyl]amine) was investigated for its potential as an intermediate in proposed functionalization reactions of olefins. RTPA)Rh111(K2-C,0-2-oxyethyl)]+ BPh4- was prepared by two published methods with limited success. A third method involved the use of nitrous oxide to oxygenate [(12-ethene)(K4-TPA)Rh1]+ to RTPA)Rh1110( -2-C,0-2-oxyethyDr. Only a trace amount of [(TPA)Rhmoc2 -C,0-2-oxyethypr was observed in the 1I-1 NMR spectrum of this reaction mixture. Initial test reactions of [(TPA)Rhilioc2_C,0-2-oxyethypr combined with substrates (aniline, toluenesulfonamide, phenylboronic acid, or benzaldehyde) were inconclusive since the results were obscured by the impuri.

Download or read book Rhodium Catalyzed C C Bond Formation Via Heteroatom Directed C H Bond Activation written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Once considered the 'holy grail' of organometallic chemistry, synthetically useful reactions employing C-H bond activation have increasingly been developed and applied to natural product and drug synthesis over the past decade. The ubiquity and relative low cost of hydrocarbons makes C-H bond functionalization an attractive alternative to classical C-C bond forming reactions such as cross-coupling, which require organohalides and organometallic reagents. In addition to providing an atom economical alternative to standard cross - coupling strategies, C-H bond functionalization also reduces the production of toxic by-products, thereby contributing to the growing field of reactions with decreased environmental impact. In the area of C-C bond forming reactions that proceed via a C-H activation mechanism, rhodium catalysts stand out for their functional group tolerance and wide range of synthetic utility. Over the course of the last decade, many Rh-catalyzed methods for heteroatom-directed C-H bond functionalization have been reported and will be the focus of this review. Material appearing in the literature prior to 2001 has been reviewed previously and will only be introduced as background when necessary. The synthesis of complex molecules from relatively simple precursors has long been a goal for many organic chemists. The ability to selectively functionalize a molecule with minimal pre-activation can streamline syntheses and expand the opportunities to explore the utility of complex molecules in areas ranging from the pharmaceutical industry to materials science. Indeed, the issue of selectivity is paramount in the development of all C-H bond functionalization methods. Several groups have developed elegant approaches towards achieving selectivity in molecules that possess many sterically and electronically similar C-H bonds. Many of these approaches are discussed in detail in the accompanying articles in this special issue of Chemical Reviews. One approach that has seen widespread success involves the use of a proximal heteroatom that serves as a directing group for the selective functionalization of a specific C-H bond. In a survey of examples of heteroatom-directed Rh catalysis, two mechanistically distinct reaction pathways are revealed. In one case, the heteroatom acts as a chelator to bind the Rh catalyst, facilitating reactivity at a proximal site. In this case, the formation of a five-membered metallacycle provides a favorable driving force in inducing reactivity at the desired location. In the other case, the heteroatom initially coordinates the Rh catalyst and then acts to stabilize the formation of a metal-carbon bond at a proximal site. A true test of the utility of a synthetic method is in its application to the synthesis of natural products or complex molecules. Several groups have demonstrated the applicability of C-H bond functionalization reactions towards complex molecule synthesis. Target-oriented synthesis provides a platform to test the effectiveness of a method in unique chemical and steric environments. In this respect, Rh-catalyzed methods for C-H bond functionalization stand out, with several syntheses being described in the literature that utilize C-H bond functionalization in a key step. These syntheses are highlighted following the discussion of the method they employ.

Download or read book Oxidative C C Bond Formation Reactivity of High Valent Nickel and Palladium Complexes written by Michael Benjamin Watson and published by . This book was released on 2017 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of both palladium and nickel catalysis over the past several decades has led to the ability to perform a multitude of C-C coupling, C-Heteroatom coupling, and C-H functionalization reactions. These reactions typically utilize a catalytic cycle involving Pd0/II/IV and Ni0/II. While using these types of catalytic cycles one can create a multitude of different hard to make bonds, it is always important to keep expanding what we view as potential catalytic intermediates to keep developing new cycles capable of new transformations. One such way to expand our knowledge of these catalytic cycles is to look at the oxidation states that are less commonly observed in catalysis. This typically involves PdI/III and NiI/III/IV. Studying these rare oxidation states allows us to determine if they have the potential to either take part in current catalytic cycles, or develop new ones that take advantage of these oxidation states. Our group has previously synthesized various PdIII and NiIII complexes with the support of N,N'- dialkyl-2,11-diaza[3.3](2,6)pyridinophane (RN4). This ligand has allowed for the isolation and characterization of these complexes that are typically seen as unstable letting us study their reactivity. First, we investigated the effects of ligand flexibility on the stabilization of PdIII complexes by synthesizing several ligands. The "flexible" ligands had a 1,4,7-triazacyclononane framework and the "rigid" ligands had a diazabicylononanone framework. Seeing that the flexible 1,4,7- triazacyclononane ligands seemed to be better at stabilizing the high valent palladium, we continued using it to synthesize organometallic nickel complexes. These complexes proved very easy to oxidize allowing NiII/III/IV oxidation states to be isolated and fully characterized. The oxidative reactivity was studied for these three nickel complexes looking at oxidative addition with organic halides, aerobic oxidation, and most interestingly photolysis that resulted in much faster reductive elimination from the NiIV species. Lastly, we investigated the ligand modifications that can be done to either stabilize or destabilize high valent NiIII species using a N,N'-dialkyl-2,11- diaza[3.3](2,6)pyridinophane ligand that was modified to observe the effect on differing amounts of steric bulk and electronic effects. Studying these rare high valent complexes is important so we can continue to expand the scope of what catalytic transformations we can use to improve our daily lives.

Download or read book Selective Reactions of Various Biomolecules Catalyzed by Platinum II and Palladium II Complexes written by Natalia V. Kaminskaia and published by . This book was released on 1998 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first example of a specific coordination between the side chain of tryptophan and a transition metal. The amide bond in the resulted complexes is hydrolytically cleaved by the external water. The rate enhancement of 104-105-fold in peptide hydrolysis is somewhat lower than in the reactions of nitriles and urea because catalysts activate only peptide substrates, and do not produce M(II)-bound hydroxide (M(II) is Pt(II) or Pd(II)). New selectivity of cleavage is shown.