Download or read book Synthesis and Asymmetric Reactivity of Electronically and Sterically Differentiating Chiral Cyclopentadienyl Metal Complexes written by Ronald Lee Halterman and published by . This book was released on 1985 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design and Synthesis of Electronically and Sterically Variable Chiral Cyclopentadienyl Transition Metal Complexes and Their Application in Asymmetric Transformations written by Timothy Michael Ramsey and published by . This book was released on 1994 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetically Controlled Stepwise Syntheses of a Heterometallic Complex and a Tetrahedral Chiral at Metal Complex written by Kenichi Endo and published by Springer Nature. This book was released on 2021-04-01 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes novel synthetic methodologies for two kinds of structurally elaborate metal complexes: a heterometallic complex and a tetrahedral chiral-at-metal complex. The book provides the tools and inspiration to chemists for development of metal complexes with wide structural diversity than had previously been possible. For each of the two topics, existing synthetic methods for similar compounds are discussed first, and then new strategies are presented, followed by the demonstration of the synthesis of novel compounds supported by experimental results. Both of the final products in this research, a Co–Ni heterometallic complex covered in the first topic and a tetrahedral chiral-at-metal complex in the second one are difficult to obtain by using common synthetic methods for thermodynamic reasons. This research achieved highly selective syntheses of these compounds using newly designed strategies that enable precise kinetic control. Such an approach will be useful for synthesizing other new metal complexes. Since the last century, organic chemistry has flourished with the development of a variety of synthetic techniques that make precise kinetic control possible. Coordination chemistry of 3d or main-group transition metals has been mainly based on simple one-step reactions that yield only thermodynamic products. The publication of this book helps pave the way to kinetically controlled precise syntheses of various metal complexes.
Download or read book Axially Chiral Compounds written by Bin Tan and published by John Wiley & Sons. This book was released on 2021-11-22 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Axially Chiral Compounds Explore this comprehensive and current volume summarizing the characteristics, synthesis, and applications of axial chirality Appearing widely in natural products, biologically active molecules, asymmetric chemistry, and material science, axially chiral motifs constitute the core backbones of the majority of chiral ligands and organocatalysts in asymmetric catalysis. In a new work of particular relevance to synthetic chemists, Axially Chiral Compounds: Asymmetric Synthesis and Applications delivers a clearly structured and authoritative volume covering the classification, characteristics, synthesis, and applications of axial chirality. A must read for every synthetic chemist practicing today, the book follows the development history, research status, and applications of axial chirality. An introductory chapter familiarizes the reader with foundational material before the distinguished authors describe the different classes and the synthesis of axial chiral compounds used in asymmetric synthesis. The book concludes with a focus on the applications of chiral ligands, chiral catalysts, and materials. Readers will also benefit from the inclusion of: A thorough introduction to asymmetric synthesis, including biaryls atropisomers, heterobiaryls atropisomers, and non-biaryls atropisomers Explorations of chiral allene, spiro skeletons, and natural products Practical discussions of asymmetric transformation, chiral ligands, and chiral catalysts An examination of miscellaneous applications of axially chiral compounds Perfect for organic chemists, chemists working with or on organometallics, catalytic chemists, and materials scientists, Axially Chiral Compounds: Asymmetric Synthesis and Applications will also earn a place in the libraries of natural products chemists who seek a one-stop reference for compounds exhibiting axial chirality.
Download or read book Chiral Auxiliaries and Ligands in Asymmetric Synthesis written by J. Seyden-Penne and published by Wiley-Interscience. This book was released on 1995-10-23 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Table of Contents Preface Abbreviations Introduction 1 1 Enantiomerically Pure Chiral Auxiliaries 43 2 Chiral Reagents 87 3 Chiral Catalysis and Catalysts Bearing Chiral Ligands 117 4 Asymmetric Deprotonations and Protonations 143 5 Alkylations and Related Reactions 157 6 Additions to C=O and C=N Double Bonds 209 7 Additions to Carbon-Carbon Double Bonds 367 8 Additions to Double Bonds Bearing Heteroatoms. Oxidations of Sulfides and Selenides 503 9 Cycloadditions 513 10 Sigmatropic Rearrangements 593 11 Transition Metal Catalyzed Reactions 619 References 637 Index 707.
Download or read book Chiral Cyclopentadienyl Metal Complexes written by Philip John Davies and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Asymmetric Cyclization Reactions of Chiral Cyclopentadienylruthenium and Indenylruthenium Complexes written by Michael Christian Ryan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Using transition metal catalysis to rapidly increase complexity for the construction of small molecules has been one of the most important areas of research in the field of synthetic organic chemistry. In particular, cyclopentadienylruthenium (CpRu) catalysis has previously been shown by our research group and others to be a selective, cost-effective, and atom-economical means of achieving this goal. In an effort to extend CpRu catalysis to enantioselective variants of these reactions, our group had previously developed CpRu complexes containing tethered chiral sulfoxides for their successful application towards asymmetric allylic substitution reactions. This work describes our efforts to expand the chemistry of these CpRu-sulfoxide complexes and to synthesize novel chiral CpRu and indenylruthenium (IndRu) catalysts for the discovery of new catalytic asymmetric cyclization reactions. CpRu-sulfoxide complexes were used to perform an asymmetric redox bicycloisomerization reaction that constructed [3.1.0] and [4.1.0] bicycles from propargyl alcohols. Initial reaction optimization was performed on 1,7-enynes due to the products' similarity to known triple-reuptake inhibitor GSK1360707. CpRu complex containing a tethered para-methoxy sulfoxide ligand proved to be the optimal catalyst for this reaction. Variation of the 1,7-enyne substrate structure revealed that a bulky 2,4,6-triisopropylbenzenesulfonyl (Tris) protecting group on the nitrogen-containing backbone was essential for observing high enantioselectivities for [4.1.0] bicycles. While THF proved to be the optimal solvent for redox isomerization of [4.1.0] bicycles, acetone provided the best results for [3.1.0] bicycles. Enantiomeric ratios as high as 98.5:1.5 were observed with Tris-containing [3.1.0] bicycles. The chemistry could be extended to 1,6-enynes containing other substrate tethers, including tosyl, diphenyl phosphoramidate, and dibenzyl malonate tethers. Nitrogen protecting groups were shown to be removable under reducing conditions. Catalysis performed with enantiomerically enriched propargyl alcohols revealed a matched/mismatched effect that was strongly dependent on the nature of the solvent. To the best of our knowledge, this methodology was the first example of a ruthenium-catalyzed asymmetric cycloisomerization reaction. Unfortunately, CpRu-sulfoxide complexes were shown to be inefficient and poorly selective catalysts for the enyne cycloisomerization and redox isomerization/C-H insertion reactions. We hypothesized that either the bound sulfoxide ligand was too electron-rich or that the catalyst had an insufficient number of coordination sites available for catalysis. In order to test our hypothesis, we synthesized CpRu complexes that contained more electron-withdrawing S-chiral ligands. While chiral sulfimide- and sulfinamide-containing complexes could promote enyne cycloisomerization, these catalysts were poorly enantioselective. These results led us to believe that the ligands were too weakly ligated to the metal center and decomplexed under the reaction conditions. Novel coordinatively unsaturated chiral indenylruthenium complexes with a tethered chiral sulfoxide were designed and synthesized. Enantiomeric ratios of up to 75:25 for enyne cycloisomerization and 84:16 for enyne hydroxycyclization could be obtained using these catalysts. When applied to the asymmetric redox isomerization/C-H insertion reaction, chiral indenylruthenium complexes could promote this reaction in up to 90:10 e.r. The main disadvantage of using these tethered complexes is that they are not commercially available and must be made through multistep syntheses. We discovered that commercially available catalyst CpRu(MeCN)3PF6, when used in conjunction with a chiral phosphoramidite ligand, can perform an asymmetric interrupted metallo-ene reaction of (E)-allylic chlorides in excellent enantioselectivity. To our knowledge, this represents the first example of using CpRu-phosphoramidite complexes for a catalytic asymmetric transformation. The C1-symmetry and 3,3'-substitution on the BINOL-based phosphoramidite were key to the high levels of enantioinduction observed. Carbocyclic and heterocyclic 5- and 6-membered rings could be constructed in> 20:1 d.r. and up to 99:1 e.r. As a demonstration of the utility of this methodology, diastereoselective Friedel-Crafts reactions were performed on the chiral benzylic alcohol products that were observed to proceed with retention of configuration.
Download or read book The Design Synthesis and Application to Asymmetric Catalysis of Chiral Transition Metal Cyclopentadienyl Complexes written by Daniel Christopher Brookings and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chiral Reagents for Asymmetric Synthesis written by Leo A. Paquette and published by John Wiley & Sons. This book was released on 1999 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contiene: Introduction; Recent Review Articles and Monographs; Organic Synthesis Procedures Featuring Chiral, non-Racemic Reagent Preparation.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Reactivity of Transition Metal Complexes Containing Pentamercurated Cyclopentadienyl Ligands written by Young Hee Han and published by . This book was released on 1993 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Asymmetric Synthesis written by Robert E. Gawley and published by Pergamon Press. This book was released on 1996 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading references are provided to natural product synthesis that have been accomplished using a given reaction as a key step. PIn addition to tables of examples that show high selectivity, a transition state analysis is presented to explain - to the current level of understanding - the stereoselectivity of each reaction. In one case (Cram's rule) the evolution of the current theory is detailed from its first tentative (1952) postulate to the current Felkin-Anh-Heathcock formalism. For other reactions, only the currently accepted rationale is presented. Examination of these rationales also exposes the weaknesses of current theories, in that they cannot always explain the experimental observations.-
Download or read book Chiral Ruthenium cyclopentadienyl Complexes for Use in Asymmetric Synthesis written by Richard W. Kemp and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chiral Sulfur Reagents written by Marian Mikolajczyk and published by CRC Press. This book was released on 1997-06-09 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last three decades, more than 40 different classes of chiral (mirror-image) sulfur compounds have been described, and a number of useful procedures and applications have been developed for their use. Emphasizing modern methodologies, Chiral Sulfur Reagents demonstrates the great potential of enantionmerically pure sulfur reagents in transmitting chirality to other centers. Each chapter highlights the synthesis and synthetic uses of a particular class of chiral sulfur reagent, followed by examples of the most important experimental procedures.
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1985 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asymmetric Synthesis of Chiral at Metal Complexes with Pentadentate Bis oxazoline Ligands written by Michael Seitz and published by . This book was released on 2004 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
