Development in Phosphorus Ligands and Their Applications in Rhodium-catalyzed Reactions

Development in Phosphorus Ligands and Their Applications in Rhodium-catalyzed Reactions
Author: Bonan Cao
Publisher:
Total Pages: 130
Release: 2013
Genre: Chirality
ISBN:
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Transition-metal-catalyzed reactions have become powerful tools in the production of pharmaceuticals and fine chemicals. In the past decades, asymmetric catalysis, especially chiral rhodium catalysts, hold an increasing role of efficiently building up chirality. In this dissertation, we will focus on the development of several rhodium phosphorus catalysts and their applications in hydroformylation and asymmetric hydrogenation reactions. Chapter I outlined the development of a new family of sterrically rigid hybrid phosphine-phosphoramidite ligands. The new catalyst system shows excellent compatibility versus styrene, vinyl acetate, allyl cyanide and their derivatives. The relationship between the enantioselectivity and the substituent on ligands is investigated by systematic variation on the ligand structures. In chapter II, further application of phosphine-phosphoramidite ligands in asymmetric hydroformylation of N-allylamides and N-allylsulfonamides provides a new approach to chiral [beta]2-amino aldehydes, acids, and alcohols for pharmaceutical and synthetic chemistry. Up to 99% ee and 9700 turnovers stands as the best result achieved in this type of hydroformylation reaction. Chapter III focuses on the synthesis of a series of aryl substituted dihydropyrroles via this hydroformylation. The significant improvement in reactivity and chemoselectivity suggests a potential application in building large heterocycles in an atom efficient fashion. In chapter IV, I report a successful monodentate phosphoramidite ligand for the catalytic asymmetric hydrogenation of dehydroamino esters. The easy modulared structure allowed us to further expand the scope of the ligand.

Synthesis and Development of Phosphorus Ligands in the Application of Rhodium-catalyzed Hydroformylation

Synthesis and Development of Phosphorus Ligands in the Application of Rhodium-catalyzed Hydroformylation
Author: Xin Zheng
Publisher:
Total Pages: 123
Release: 2015
Genre: Hydroformylation
ISBN:
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Rhodium-catalyzed hydroformylation reaction is one of the most powerful homogeneous catalytic processes in the synthesis of aldehydes that can be widely applied in pharmaceuticals and fine chemicals. The design and synthesis phosphorus ligands combine with rhodium precursor used as catalysts is essentially important in the development of this reaction. This dissertation mainly focuses on the design, synthesis and application of efficient phosphorus ligands in rhodium-catalyzed hydroformylation. Asymmetric hydroformylation reaction (AHF), especially rhodium-catalyzed AHF has played a central role to construct chiral aldehydes in only one step. Although tons of chiral phosphorus ligands have been reported, few of them exhibited practicable enantioselectivities and regioselectivities. We report a new family of highly tunable bisphospholane ligands in the application of series of terminal and internal olefins, affording up to 88% for styrene derivatives, 93% ee for vinyl acetate derivatives, 93% ee for dihydrofuran and 96% for dihyropyrrole. A systematic screening different substituents on the ligand showed that ortho chloride on phenyl moiety was the successful structure, achieving the highest regio- and enantioselectivity. To expand the scope of substrates, especially the more challenging 1,1-disubstituted olefins, we first report the asymmetric hydroformylation of 1,1-disubstituted allylphthalimides by employing chiral ligand 1,2-bis[(2S, 5S)-2,5-diphenylphospholano]ethane [(S, S)-Ph-BPE] to yield a series of beta-3-aminoaldehydes with up to 95% enantioselectivity. This asymmetric procedure provides an efficient alternative route to prepare chiral beta-3-amino acids and alcohols that are key structural elements of beta-aminobutyric acid. Hydroaminomethylation is the tandem reaction of hydroformylation/hydrogenation. This efficient reaction is utilized to build nitrogen-containing compounds, which are interesting in pharmaceutics and fine chemicals. In this chapter, we disclose the synthesis of 4-aryl-2,3-dihyropyrrole derivatives by rhodium-catalyzed intramolecular hydrominometylation reaction with up to 99% yield.

Phosphorus(III)Ligands in Homogeneous Catalysis

Phosphorus(III)Ligands in Homogeneous Catalysis
Author: Paul C. J. Kamer
Publisher: John Wiley & Sons
Total Pages: 673
Release: 2012-05-09
Genre: Technology & Engineering
ISBN: 1118299701
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Over the last 60 years the increasing knowledge of transition metal chemistry has resulted in an enormous advance of homogeneous catalysis as an essential tool in both academic and industrial fields. Remarkably, phosphorus(III) donor ligands have played an important role in several of the acknowledged catalytic reactions. The positive effects of phosphine ligands in transition metal homogeneous catalysis have contributed largely to the evolution of the field into an indispensable tool in organic synthesis and the industrial production of chemicals. This book aims to address the design and synthesis of a comprehensive compilation of P(III) ligands for homogeneous catalysis. It not only focuses on the well-known traditional ligands that have been explored by catalysis researchers, but also includes promising ligand types that have traditionally been ignored mainly because of their challenging synthesis. Topics covered include ligand effects in homogeneous catalysis and rational catalyst design, P-stereogenic ligands, calixarenes, supramolecular approaches, solid phase synthesis, biological approaches, and solubility and separation. Ligand families covered in this book include phosphine, diphosphine, phosphite, diphosphite, phosphoramidite, phosphonite, phosphinite, phosphole, phosphinine, phosphinidenene, phosphaalkenes, phosphaalkynes, P-chiral ligands, and cage ligands. Each ligand class is accompanied by detailed and reliable synthetic procedures. Often the rate limiting step in the application of ligands in catalysis is the synthesis of the ligands themselves, which can often be very challenging and time consuming. This book will provide helpful advice as to the accessibility of ligands as well as their synthesis, thereby allowing researchers to make a more informed choice. Phosphorus(III) Ligands in Homogeneous Catalysis: Design and Synthesis is an essential overview of this important class of catalysts for academic and industrial researchers working in catalyst development, organometallic and synthetic chemistry.

Rhodium Catalyzed Hydroformylation

Rhodium Catalyzed Hydroformylation
Author: Piet W.N.M. van Leeuwen
Publisher: Springer
Total Pages: 286
Release: 2000-09-30
Genre: Science
ISBN: 9780792365518
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In the last decade there have been numerous advances in the area of rhodium-catalyzed hydroformylation, such as highly selective catalysts of industrial importance, new insights into mechanisms of the reaction, very selective asymmetric catalysts, in situ characterization and application to organic synthesis. The views on hydroformylation which still prevail in the current textbooks have become obsolete in several respects. Therefore, it was felt timely to collect these advances in a book. The book contains a series of chapters discussing several rhodium systems arranged according to ligand type, including asymmetric ligands, a chapter on applications in organic chemistry, a chapter on modern processes and separations, and a chapter on catalyst preparation and laboratory techniques. This book concentrates on highlights, rather than a concise review mentioning all articles in just one line. The book aims at an audience of advanced students, experts in the field, and scientists from related fields. The didactic approach also makes it useful as a guide for an advanced course.

Modern Rhodium-Catalyzed Organic Reactions

Modern Rhodium-Catalyzed Organic Reactions
Author: P. Andrew Evans
Publisher: John Wiley & Sons
Total Pages: 496
Release: 2006-03-06
Genre: Science
ISBN: 352760409X
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Rhodium has proven to be an extremely useful metal due to its ability to catalyze an array of synthetic transformations, with quite often-unique selectivity. Hydrogenation, C-H activation, allylic substitution, and numerous other reactions are catalyzed by this metal, which presumably accounts for the dramatic increase in the number of articles that have recently emerged on the topic. P. Andrew Evans, the editor of this much-needed book, has assembled an internationally renowned team to present the first comprehensive coverage of this important area. The book features contributions from leaders in the field of rhodium-catalyzed reactions, and thereby provides a detailed account of the most current developments, including: Rhodium-Catalyzed Asymmetric Hydrogenation (Zhang) Rhodium-Catalyzed Hydroborations and Related Reactions (Brown) Rhodium-Catalyzed Asymmetric Addition of Organometallic Reagents to Electron Deficient Olefins (Hayashi) Recent Advances in Rhodium(I)-Catalyzed Asymmetric Olefin Isomerization and Hydroacylation Reactions (Fu) Stereoselective Rhodium(I)-Catalyzed Hydroformylation and Silylformylation Reactions and Their Application to Organic Synthesis (Leighton) Carbon-Carbon Bond-Forming Reactions Starting from Rh-H or Rh-Si Species (Matsuda) Rhodium(I)-Catalyzed Cycloisomerization and Cyclotrimerization Reactions (Ojima) The Rhodium(I)-Catalyzed Alder-ene Reaction (Brummond) Rhodium-Catalyzed Nucleophilic Ring Cleaving Reactions of Allylic Ethers and Amines (Fagnou) Rhodium(I)-Catalyzed Allylic Substitution Reactions and their Applications to Target Directed Synthesis (Evans) Rhodium(I)-Catalyzed [2+2+1] and [4+1] Carbocyclization Reactions (Jeong) Rhodium(I)-Catalyzed [4+2] and [4+2+2] Carbocyclizations (Robinson) Rhodium(I)-Catalyzed [5+2], [6+2], and [5+2+1] Cycloadditions: New Reactions for Organic Synthesis (Wender) Rhodium(II)-Stabilized Carbenoids Containing both Donor and Acceptor Substituents (Davies) Chiral Dirhodium(II)Carboxamidates for Asymmetric Cyclopropanation and Carbon-Hydrogen Insertion Reactions (Doyle) Cyclopentane Construction by Rhodium(II)-Mediated Intramolecular C-H Insertion (Taber) Rhodium(II)-Catalyzed Oxidative Amination (DuBois) Rearrangement Processes of Oxonium and Ammonium Ylides Formed by Rhodium(II)-Catalyzed Carbene-Transfer (West) Rhodium(II)-Catalyzed 1,3-Dipolar Cycloaddition Reactions (Austin) "Modern Rhodium-Catalyzed Organic Reactions" is an essential reference text for researchers at all levels in the general area of organic chemistry. This book provides an invaluable overview of the most significant developments in this important area of research, and will no doubt be an essential text for researchers at academic institutions and professionals at pharmaceutical/agrochemical companies.