Complexes Diène Du Rhodium Et de L'iridium Portant Des Ligands Diphénylphosphinoferrocényl Thioéther

Complexes Diène Du Rhodium Et de L'iridium Portant Des Ligands Diphénylphosphinoferrocényl Thioéther PDF Author: Ekaterina Kozinets
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Book Description
New diene rhodium complexes with diphenylphosphinoferrocenylthioether ligands [Rh(P,SR)(diene)]X (diene = COD, NBD; X = Cl-, BF4-) were synthesized and fully characterized. The molecular structure of the cationic complexes [Rh(P,SR)(diene)]+BF4- shows a slightly distorted square planar geometry. For the chloride complexes, [Rh(P,SR)(diene)Cl], a combination of NMR and IR spectroscopy and DFT calculations points to a four coordinate square planar geometry with the diene ligand, the chlorine and the phosphorus atoms in the coordination sphere and with a dangling thioether function. It was found that rhodium complexes [Rh(P,SR)(diene)]X are good structural and functional models to study the ketone asymmetric hydrogenation mechanism catalyzed by the iridium complexes [Ir(P,SBut)(COD)Cl]. For the [Rh(P,SBut)(diene)]X derivatives the rate of hydrogenation and the nantioselectivity change in the order COD-Cl > COD-BF4 > NBD-BF4 > NBD-Cl. For the complexes with the NBD ligand the activity/enantioselectivity change in the order But ” Et > Ph > Bz. By use of parahydrogen NMR spectrometry, it was established that the catalyst activation involves the reaction of the rhodium complexes [Rh(P,SBut)(diene)]X with dihydrogen, which occurs in two steps through the generation of an intermediate [Rh(P,SR)(alkene-alkyl)]([Rh(P,SR)(1-kappa-4,5-eta-C8H13)] for the COD complexes) followed by the formation of a solvated complex [Rh(P,SR)(Solv)2]+ (Solv = MeOH, MeCN, acetone). Hydrogenation of the NBD ligand proceeds faster than that of the COD ligand. The rhodium complex [Rh(P,SBut)(MeOH)2]+ promotes a very rapid H/D exchange between H2 and the deuterated solvent via a dihydride species [Rh(P,SBut)(MeOH)2H2]+, which is accessible according to the DFT calculations. Addition of L (py or MeCN) to the solution of [Rh(P,SBut)(diene)]X in the presence of H2 at low temperature results in the formation of a diastereomeric dihydride species [Rh(P,SBut)L2H2]+, the structure of which was established on the basis of the NMR spectroscopic data.

Complexes Diène Du Rhodium Et de L'iridium Portant Des Ligands Diphénylphosphinoferrocényl Thioéther

Complexes Diène Du Rhodium Et de L'iridium Portant Des Ligands Diphénylphosphinoferrocényl Thioéther PDF Author: Ekaterina Kozinets
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Book Description
New diene rhodium complexes with diphenylphosphinoferrocenylthioether ligands [Rh(P,SR)(diene)]X (diene = COD, NBD; X = Cl-, BF4-) were synthesized and fully characterized. The molecular structure of the cationic complexes [Rh(P,SR)(diene)]+BF4- shows a slightly distorted square planar geometry. For the chloride complexes, [Rh(P,SR)(diene)Cl], a combination of NMR and IR spectroscopy and DFT calculations points to a four coordinate square planar geometry with the diene ligand, the chlorine and the phosphorus atoms in the coordination sphere and with a dangling thioether function. It was found that rhodium complexes [Rh(P,SR)(diene)]X are good structural and functional models to study the ketone asymmetric hydrogenation mechanism catalyzed by the iridium complexes [Ir(P,SBut)(COD)Cl]. For the [Rh(P,SBut)(diene)]X derivatives the rate of hydrogenation and the nantioselectivity change in the order COD-Cl > COD-BF4 > NBD-BF4 > NBD-Cl. For the complexes with the NBD ligand the activity/enantioselectivity change in the order But ” Et > Ph > Bz. By use of parahydrogen NMR spectrometry, it was established that the catalyst activation involves the reaction of the rhodium complexes [Rh(P,SBut)(diene)]X with dihydrogen, which occurs in two steps through the generation of an intermediate [Rh(P,SR)(alkene-alkyl)]([Rh(P,SR)(1-kappa-4,5-eta-C8H13)] for the COD complexes) followed by the formation of a solvated complex [Rh(P,SR)(Solv)2]+ (Solv = MeOH, MeCN, acetone). Hydrogenation of the NBD ligand proceeds faster than that of the COD ligand. The rhodium complex [Rh(P,SBut)(MeOH)2]+ promotes a very rapid H/D exchange between H2 and the deuterated solvent via a dihydride species [Rh(P,SBut)(MeOH)2H2]+, which is accessible according to the DFT calculations. Addition of L (py or MeCN) to the solution of [Rh(P,SBut)(diene)]X in the presence of H2 at low temperature results in the formation of a diastereomeric dihydride species [Rh(P,SBut)L2H2]+, the structure of which was established on the basis of the NMR spectroscopic data.

Study of Rhodium and Silver Complexes with Thioether- and Sulfoxide-functionalized N-heterocycliccarbene Ligands

Study of Rhodium and Silver Complexes with Thioether- and Sulfoxide-functionalized N-heterocycliccarbene Ligands PDF Author: 余祈瑩
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Comprehensive Coordination Chemistry II

Comprehensive Coordination Chemistry II PDF Author: J. A. McCleverty
Publisher: Newnes
ISBN: 0080913164
Category : Science
Languages : en
Pages : 11845

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Book Description
Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.

Transition-metal Complexes Containing Phosphorus Ligands

Transition-metal Complexes Containing Phosphorus Ligands PDF Author: Jeffrey John Levison
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 5

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Synthesis and Reactions of Complexes of Rhodium and Iridium Having Chelating N,O-donor Ligands

Synthesis and Reactions of Complexes of Rhodium and Iridium Having Chelating N,O-donor Ligands PDF Author: Namadzavho Enos Sitabule
Publisher:
ISBN:
Category : Rhodium
Languages : en
Pages : 302

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Olefin Polymerization

Olefin Polymerization PDF Author: Walter Kaminsky
Publisher: Wiley-VCH
ISBN: 9783527317424
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
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.

Nucleophilic Aromatic Substitution of Hydrogen

Nucleophilic Aromatic Substitution of Hydrogen PDF Author: Oleg N. Chupakhin
Publisher: Academic Press
ISBN: 0323140599
Category : Science
Languages : en
Pages : 378

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Book Description
Nucleophilic aromatic substitution in carbo- and heteroaromatic systems is a subject of considerable interest to chemists. This book uniquely addresses the systematic analysis of a vast range of nucleophilic substitutions of aromatic hydrogen. - Nucleophilic displacement of hydrogen (the S N/H reactions) in pi-deficient aromatics, such as nitroarenes, arene-metal complexes, and the like - Nucleophilic displacement of hydrogen in heterocyclic substrates such as pyridines, their aza and benzo analogs, pyrylium and thiapyrylium cations, and other heterocycles - Mechanisms for the S N/H reactions (S N/H(AE), vicarious nucleophilic substitutions, and radical S N/H substitutions

Hydrogen Bonding in Organic Synthesis

Hydrogen Bonding in Organic Synthesis PDF Author: Petri M. Pihko
Publisher: John Wiley & Sons
ISBN: 3527627855
Category : Science
Languages : en
Pages : 395

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Book Description
This first comprehensive overview of the rapidly growing field emphasizes the use of hydrogen bonding as a tool for organic synthesis, especially catalysis. As such, it covers such topics as enzyme chemistry, organocatalysis and total synthesis, all unified by the unique advantages of hydrogen bonding in the construction of complex molecules from simple precursors. Providing everything you need to know, this is a definite must for every synthetic chemist in academia and industry.

Directed Metallation

Directed Metallation PDF Author: Naoto Chatani
Publisher: Springer Science & Business Media
ISBN: 3540758089
Category : Science
Languages : en
Pages : 214

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Book Description
This book provides the broad scientific readership with a comprehensive summary and critical overview of a topic in organometallic chemistry. A wide variety of catalytic functionalization reactions of C-H bonds by the utilization of a chelation have been developed recently and are comprehensively discussed in this book by leading experts. In addition, new approaches to directed hydrometalation and directed carbometalation as a key step are also discussed.

Metal Catalyzed Cascade Reactions

Metal Catalyzed Cascade Reactions PDF Author: Thomas J.J. Müller
Publisher: Springer
ISBN: 3540329595
Category : Science
Languages : en
Pages : 0

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Book Description
This book highlights cyclization via carbopalladation and acylpalladation and Heck-pericyclic sequences. They discuss p-allyl palladium-based cascade reactions, Michael-type additions as an entry to transition-metal-promoted cyclizative transformations, and sequential or consecutive palladium-catalyzed processes, and show Pauson-Khand cascades, metal-catalyzed cyclizations of acyclic precursors, as well as cascade and sequential ruthenium-catalyzed transformations. This is a comprehensive overview of an exciting and highly dynamic, and innovative methodological concept.