Fluorine-containing Amino Acids
Fluorine-containing Amino Acids

Author: Valery P. Kukhar

Publisher: John Wiley & Sons

Published: 1995-04-06

Total Pages: 432

ISBN-13:

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In recent years, organo-fluorine chemistry has made a marked impact on the design and synthesis of a large variety of biologically active molecules, such as steroids, carbohydrates, amines, amino acids, peptides and other natural products. Naturally occurring amino acids play a pivotal role in living systems, and therefore synthetic fluorine-containing amino acids have been of significant interest to researchers working towards the understanding and modification of physiological processes. Fluorine-containing Amino Acids: is the first volume devoted to the synthesis and properties of fluorine-containing amino acids pays special attention to the preparation of enantiomerically pure acids (which are essential to the modern pharmaceutical industry) deals with a rapidly expanding field of research has been written by experienced researchers who are responsible for many developments in the field highlights the interdisciplinary nature of this topic Fluorine-containing Amino Acids is the only dedicated reference in this subject and will be essential for researchers in synthetic organic, peptide, natural product, and medicinal chemistry and biochemistry.

Organo-catalytic Strategies Towards Alpha, Alpha - Disubstituted Amino Acid Derivatives
Organo-catalytic Strategies Towards Alpha, Alpha - Disubstituted Amino Acid Derivatives

Author: Henning Vogt

Publisher:

Published: 2006

Total Pages: 195

ISBN-13: 9783832513825

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The class of non-proteinogenic a,a u2011disubstituted amino acids and their derivatives is of high interest to biochemical and pharmacological research. This predicates on their ability to alter certain chemical and physicochemical properties of peptides and related structures. Moreover, the close structural relatedness to biologically relevant endogenous amino acid derivatives qualifies them in many cases to act as enzyme inhibitors or receptor antagonists.In the present study, the development of new strategies towards the synthesis of N u2011protected a,a u2011disubstituted amino aldehydes and their derivatives is demonstrated. Starting from ketones, a,a u2011disubstituted aldehydes were prepared in two or three steps. These aldehydes were subjected to stereoselective organo-catalysed a u2011amination reactions. The transfer of a procedure known for the a u2011amination of a u2011unbranched aldehydes with azodicarboxylates to racemic a u2011branched aldehydes delivered N u2011protected aminoaldehydes in up to 87 % yield and 86 % ee. The conversion of the amination products to the corresponding N u2011protected 4,4 u2011disubstituted oxazolidinones was accomplished, after in situ-reduction, in two additional steps.In addition to this method, a new strategy was devised using sulfonyl azides as aminating agent to deliver a u2011sulfamidated a,a u2011disubstituted aldehydes in up to 55 % yield and 86 % ee. A mechanism was proposed, which differs fundamentally from the mechanistic model usually ascribed to enamine catalysis. The transformation of the sulfamidation product into the free amino acid was accomplished in two steps.Since the two concepts follow different mechanistic routes, different enantiomers of N u2011protected, a,a u2011disubstituted aminoaldehydes are accessible by one catalyst. All reactions involved in the latter approach are free of transition metals. Therefore, the presented strategy could prove to be especially useful for medicinal chemistry.

Catalytic Asymmetric Synthesis
Catalytic Asymmetric Synthesis

Author: Takahiko Akiyama

Publisher: John Wiley & Sons

Published: 2022-05-27

Total Pages: 798

ISBN-13: 1119736412

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Catalytic Asymmetric Synthesis Seminal text presenting detailed accounts of the most important catalytic asymmetric reactions known today This book covers the preparation of enantiomerically pure or enriched chemical compounds by use of chiral catalyst molecules. While reviewing the most important catalytic methods for asymmetric organic synthesis, this book highlights the most important and recent developments in catalytic asymmetric synthesis. Edited by two well-qualified experts, sample topics covered in the work include: Metal catalysis, organocatalysis, photoredox catalysis, enzyme catalysis C–H bond functionalization reactions Carbon–carbon bond formation reactions, carbon–halogen bond formation reactions, hydrogenations, polymerizations, flow reactions Axially chiral compounds Retaining the best of its predecessors but now thoroughly up to date with the important and recent developments in catalytic asymmetric synthesis, the 4th edition of Catalytic Asymmetric Synthesis serves as an excellent desktop reference and text for researchers and students, from upper-level undergraduates all the way to experienced professionals in industry or academia.

Asymmetric Phase Transfer Catalysis
Asymmetric Phase Transfer Catalysis

Author: Keiji Maruoka

Publisher: John Wiley & Sons

Published: 2008-09-08

Total Pages: 228

ISBN-13: 3527622632

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Edited by the leading expert on the topic, this is the first book to present the latest developments in this exciting field. Alongside the theoretical aspects, the top contributors provide practical protocols to give readers additional important information otherwise unavailable. A must for every synthetic chemist in academia and industry.

New Methods for the Synthesis of Alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl Imines AND The Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide Organocatalysts
New Methods for the Synthesis of Alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl Imines AND The Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide Organocatalysts

Author: Melissa Ann Herbage

Publisher:

Published: 2009

Total Pages: 376

ISBN-13:

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Abstract New Methods for the Synthesis of alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl Imines AND The Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide Organocatalysts by Melissa Ann Herbage Doctor of Philosophy in Chemistry University of California, Berkeley Professor Jonathan A. Ellman, Chair Chapter 1. Methods for the synthesis of alpha-amino acid derivatives prepared from N-tert-butanesulfinyl imines are reviewed. Chapter 2. The rhodium-catalyzed addition of arylboronic acids to N-tert-butanesulfinyl imino esters is described. This chemistry is compatible with a variety of electronically and sterically diverse arylboronic acids providing the N-tert-butanesulfinyl protected alpha-arylglycine products in good yields and high diastereoselectivities. In addition, the utility of this method is demonstrated by subjecting the enantiomerically enriched N-tert-butanesulfinyl protected products to selective synthetic manipulations with little to no racemization. The synthesis of an N-tert-butanesulfinyl isatin imine and its use in the rhodium-catalyzed addition of arylboronic acids reaction is also described. Chapter 3. The copper-catalyzed addition of bis(pinacolato)diboron to N-tert-butanesulfinyl imines is described. This chemistry is amenable to a variety of alkyl and aryl N-tert-butanesulfinyl imines and provides rapid access to use of a number of chiral alpha-amino boronate esters, a biologically relevant scaffold that is difficult to access by other means. The utility of this methodology was demonstrated by the efficient synthesis of bortezomib (Velcade®), the first FDA approved proteasome inhibitor drug. The further functionalization of the alpha-amino boronate products is also described. This includes the homologation of the alpha-amino boronate ester products as well as the conversion of the boronate ester to the potassium trifluoroborate salt. The application of this methodology for the enantioselective synthesis of alpha-amino boronate esters is also addressed. Chapter 4. The synthesis of new N-tert-butanesulfinyl amide organocatalysts and their application to the intermolecular aldol reaction is described. A number of catalysts were prepared in one step from commercially available amino acid precursors and were tested for their activity in the intermolecular aldol reaction. However, preliminary results indicate that the primary amine catalysts are not competitive with other amino acid derived catalysts reported in the literature. Further optimization is necessary to fully evaluate the potential for this new class of catalysts.