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Development And Application Of Chiral Phosphorus Ligands For Enantioselective Hydrogenation
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Book Synopsis Development and Application of Chiral Phosphorus Ligands for Enantioselective Hydrogenation by : Soumyadeep Chakrabortty
Download or read book Development and Application of Chiral Phosphorus Ligands for Enantioselective Hydrogenation written by Soumyadeep Chakrabortty and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis introduced a new chiral phosphorus ligand library and their application in Rh-catalyzed asymmetric hydrogenation of functionalized olefins. A cobalt-based catalyst has been developed for the synthesis of chiral cyclic amides via enantioselective hydrogenation employing a commercially available bisphosphine ligand. Chiral 5-methyl-pyrrolidinone was synthesized via Ru-catalyzed asymmetric reductive amination using levulinic acid as platform molecule.eng
Book Synopsis Development and Application of Chiral Phosphorus Ligands for Enantionselective Hydrogenation by : Soumyadeep Chakrabortty
Download or read book Development and Application of Chiral Phosphorus Ligands for Enantionselective Hydrogenation written by Soumyadeep Chakrabortty and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis P-Chiral Phosphorus Ligands: Synthesis and Application in Asymmetric Hydrogenation by : Björn Gschwend
Download or read book P-Chiral Phosphorus Ligands: Synthesis and Application in Asymmetric Hydrogenation written by Björn Gschwend and published by Cuvillier Verlag. This book was released on 2009-11-12 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Phosphorus(III)Ligands in Homogeneous Catalysis by : Paul C. J. Kamer
Download or read book Phosphorus(III)Ligands in Homogeneous Catalysis written by Paul C. J. Kamer and published by Wiley. This book was released on 2012-06-25 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Development and Applications of Chiral Phosphorus Ligands to Transition-metal Catalyzed Asymmetric Reactions by : Ce Shi (Ph. D.)
Download or read book Development and Applications of Chiral Phosphorus Ligands to Transition-metal Catalyzed Asymmetric Reactions written by Ce Shi (Ph. D.) and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Application of Chiral Phosphorus Ligands in the Catalytic Asymmetric Hydrogenation of Heteroaromatic Compounds by : Weijun Tang
Download or read book The Application of Chiral Phosphorus Ligands in the Catalytic Asymmetric Hydrogenation of Heteroaromatic Compounds written by Weijun Tang and published by . This book was released on 2008 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Phosphorus Ligands in Asymmetric Catalysis by : Armin Börner
Download or read book Phosphorus Ligands in Asymmetric Catalysis written by Armin Börner and published by . This book was released on 2008 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis and Applications of Chiral Phosphine Ligands to Catalytic Asymmetric Hydrogenation by : Antonio Belmiro Gil da Silva Fortes
Download or read book Synthesis and Applications of Chiral Phosphine Ligands to Catalytic Asymmetric Hydrogenation written by Antonio Belmiro Gil da Silva Fortes and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chiral Phosphorous Based Ligands in Earth-Abundant Transition Metal Catalysis by : Junliang Zhang
Download or read book Chiral Phosphorous Based Ligands in Earth-Abundant Transition Metal Catalysis written by Junliang Zhang and published by Elsevier. This book was released on 2023-05-27 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chiral Phosphorous Based Ligands in Earth-Abundant Transition Metal Catalysis summarizes the most significant progress in the field of chiral phosphine ligand chemistry and a broad range of earth-abundant transition metal/chiral phosphine ligand-catalyzed enantioselective transformations. The book provides an authoritative and in-depth understanding of important topics about asymmetric catalysis based on earth-abundant transition metals/chiral phosphine ligands, making it ideal for organic chemistry researchers working in the field of asymmetric catalysis, synthetic methodologies and total synthesis.The development of new chiral phosphine ligands to achieve precise stereo control in many earth-abundant transition metal-catalyzed reactions is a very important field in organic synthesis, materials science and medicinal chemistry. The asymmetric synthesis promoted by transition metal/chiral phosphine ligands provides one of the most ideal ways to produce valuable optically active chemicals. Includes a discussion of state-of-the-art asymmetric organic reactions mediated by earth-abundant transition metals and chiral phosphine ligands Features the progress and the prospect of chiral phosphine ligands in asymmetric transition metal catalysis Covers the asymmetric reactivity modes of earth-abundant transition metals and phosphine ligands
Book Synopsis Phosphorus Ligand Development for Transition Metal Catalyzed Reactions by : Kexuan Huang
Download or read book Phosphorus Ligand Development for Transition Metal Catalyzed Reactions written by Kexuan Huang and published by . This book was released on 2014 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Synthesis and Application of Bulky S-stereogenic and P- Stereogenic Chiral Ligands by : Seán Doran
Download or read book The Synthesis and Application of Bulky S-stereogenic and P- Stereogenic Chiral Ligands written by Seán Doran and published by . This book was released on 2012 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This doctoral thesis was focused on the design and synthesis of novel chiral ligands for application in asymmetric catalysis. One of the best examples of asymmetric catalysis is the asymmetric hydrogenation reaction for its atom economy, ease of access to both S and R enantiomers and almost ultimate enantiomeric excess obtainable in a multitude of substrates. There has been much investigation into this reaction and there has been a plethora of chiral ligands designed which catalyze this reaction in high enantiomeric excess using metals such as rhodium, iridium and ruthenium. The vast majority of these ligands are diphosphines with their chirality lying either on the backbone of the ligand or on the coordinating phosphorus atom itself. In the beginning of this work investigation was undertook to explore the possibility of successfully employing a new type of ligand class in the asymmetric hydrogenation reaction, namely the N-phosphino sulfinamide or PNSO ligands. PNSO ligands had been successfully applied to the asymmetric Pauson-Khand reaction in the Riera group yielding cyclopentenone Pauson-Khand adducts in high yield and very high enantioselectivity. The family of PNSO ligands prepared in the Riera group was attractive because apart from the high yields and enantioselectivities obtained from the reactions in which they were used, they proved to be easily prepared in short syntheses from commercially available starting materials. It was believed if they could be successfully applied in asymmetric hydrogenation for their ease of preparation they would be an attractive alternative to the diphosphine ligand class. Unfortunately the first two PNSO-Rh complexes successfully prepared provided low enantioselectivities and difficulties were encountered while trying to prepare further analogues. After some time trying to achieve PNSO-Rh complex analogues unsuccessfully the direction of the project was shifted away from the N-phosphino sulfinamide ligand class in asymmetric hydrogenation. The MaxPhos ligand had recently been developed in the group and had proven highly promising. A study was demanded of its substrate scope as applied in rhodium catalyzed asymmetric hydrogenation. Substrates already described in the literature were prepared and the asymmetric hydrogenation of them catalyzed by the MaxPhos-Rh precatalyst was performed and conditions to do so were optimized. Of seven substrates prepared the MaxPhos-Rh proved to hydrogenate five of those with high enantioselectivity. The TOF of the MaxPhos rhodium catalyst applied in the hydrogenation of the Z-MAC substrate was examined by monitoring the flux of hydrogen and was calculated at 0.065 s-1. MaxPhos complexes of cobalt and palladium were prepared to form part of the investigation into widening the reaction scope of the ligand. [(MaxPhos)Co2(CO)4(C2H2)] proved to catalyze the Pauson-Khand reaction of norbornadiene and 1-hexyne with 24 % yield and 28 %, a noteworthy enantiomeric excess for the catalytic asymmetric Pauson-Khand reaction. Chalcogenated derivatives of MaxPhos were prepared. The diselenide was used to explore the electronic nature of the ligand. The MaxPhos-rhodium carbonyl stretching was examined. MaxPhos-BH3 was used to prepare mono-chalcogenated MaxPhos derivatives. They were applied also in asymmetric hydrogenation once complexed to rhodium but enantiomeric excess of no more than 21 % was obtained in the hydrogenation of the substrate Z-MAC. The aminophosphine, a chiral building block and key intermediate in the preparation of the MaxPhos ligand, was used in the attempt to prepare bulky chiral amidine ligands and although two such species were prepared they proved inapplicable in asymmetric catalysis.
Book Synopsis Development in Phosphorus Ligands and Their Applications in Rhodium-catalyzed Reactions by : Bonan Cao
Download or read book Development in Phosphorus Ligands and Their Applications in Rhodium-catalyzed Reactions written by Bonan Cao and published by . This book was released on 2013 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Chiral Phosphine Ligands for Asymmetric Hydrogenation by : Elżbieta Łastawiecka
Download or read book Chiral Phosphine Ligands for Asymmetric Hydrogenation written by Elżbieta Łastawiecka and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of Effective Chiral Ligands for Catalytic Asymmetric Hydrogenation by : Weicheng Zhang
Download or read book Development of Effective Chiral Ligands for Catalytic Asymmetric Hydrogenation written by Weicheng Zhang and published by . This book was released on 2009 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Developing P-Stereogenic Phosphine Ligand for Transition Metal Catalyzed Asymmetric Hydrogenation by : Heng Wang
Download or read book Developing P-Stereogenic Phosphine Ligand for Transition Metal Catalyzed Asymmetric Hydrogenation written by Heng Wang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focusses on the discussion of how empirical ligand design works on the development of chiral pincer ligands in the field of asymmetric hydrogenation. Although the design art of bisphosphine ligands was well-established, this empirical guide for pincer ligand design is still ambiguous. Developing a ligand design guide based on the nature of metals enables synthetic chemists to improve the catalytic performance without investing large numbers of time, develop highly efficient catalysts for industrial uses, or explore new areas and mechanistic insights. Learning from the history of chiral pincer ligand development, over 14 categories of pincer ligands were reported according to the coordinating atoms by the time that this dissertation was prepared. Firstly, the ligand design and relevant catalytic performance of different ligand categories were summarized and discussed in prevalent noble metal catalysis such as Ru(II), Ir(III). Based on the nature of Fe(II) with respect to noble metals, a novel PNP-type ligand HengPNP (L) was designed and successfully synthesized. Empirical design perspectives were discussed, and the ligand was characterized by NMR, HRMS. Its corresponding Fe(II) complex was studied by X-ray crystallographic technique. However, the Fe(II) carbonyl complex was thermodynamically unstable under decent pressure. To better understand the catalytic performance and enantioselectivity of HengPNP(L), its corresponding Ir(III) complex was employed in the asymmetric hydrogenation of various ketone substrates. A C-H bond activation Ir(III) compound was successfully isolated. The Ir(III)/HengPNP was efficient on the asymmetric hydrogenation of orthosubstituted benzophenones with excellent ee and up to 500 TON. The catalyst was superior on the hydrogenation of bis-ortho-substituted benzophenones, excellent ee was achieved over the state-of-the-art Ir/f-amphox. DFT studies was conducted to shed light on the enantio-induction model of Ir/HengPNP. A novel enantio-induction mechanism was established-the change of rotation energy of ketone substrate under the steric pressure from rigid Ir/HengPNP, was responsible for the enantioselectivity. IrH/NH bifunctional mechanism was proposed for this protocol.
Book Synopsis P-stereogenic Ligands in Enantioselective Catalysis by : Arnald Grabulosa
Download or read book P-stereogenic Ligands in Enantioselective Catalysis written by Arnald Grabulosa and published by Royal Society of Chemistry. This book was released on 2011 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: P-stereogenic ligands were among the first to be used in asymmetric catalysis but synthetic difficulties and prejudices have hampered their development. However, continuous screening for new chiral ligands means that they can no longer be ignored and this rigorous reference source reflects their renaissance.The book is filled with many examples from recent primary literature. The synthetic chemist will easily be able to follow the preparation methods which are accompanied by a description of the challenges and limitations. Those working in homogenous catalysis, and wanting to increase their repertoire of ligands, will be able to establish which have already been used in each reaction and their performance.This book provides comprehensive coverage of the application of P-stereogenic ligands in homogeneous catalysis. It begins with a brief chapter on generalities of P-stereogenic compounds: history, configurational stability, and interconversions among them.The book then goes on to describe the main preparative methods, from resolution of racemates to enantioselective catalysis, before focusing on the catalytic applications of P-stereogenic ligands. Chapter 7 describes the use of the ligands in catalytic hydrogenation and related reactions whereas chapter 8 deals with other reactions, mainly C-C bond forming reactions. The aim of these two final chapters is to give an outline of the usefulness of the ligands in homogeneous catalysis.
Book Synopsis Chiral Sulfur Ligands by : Hélène Pellissier
Download or read book Chiral Sulfur Ligands written by Hélène Pellissier and published by Royal Society of Chemistry. This book was released on 2009 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this book is to show the high potential of chiral sulfur-containing ligands to promote numerous asymmetric catalytic transformations. These ligands can now be recognised as real competitors to the more usual phosphorus- or nitrogen-containing ligands.
