Thieme Chemistry Journal Awardees - Where Are They Now? Asymmetric Brønsted Acid Catalyzed Transfer Hydrogenations

Abstract

Asymmetric hydrogenations are of great importance in the synthesis of optically active amines. This account highlights the development of the first metal-free transfer hydrogenation that is both highly enantioselective and inspired by nature’s dehydrogen­ase. Further focus is given to the extension of this bioinspired process to provide a variety of valuable, biologically active products and natural products under mild reaction conditions. 1 Introduction 2 Nature’s Reductions: Dehydrogenases as a Role Model 3 Brønsted Acid catalyzed Transfer Hydrogenation of Ketimines 4 Asymmetric Organocatalytic Reduction of Quinolines 5 Asymmetric Organocatalytic Reduction of N-Heterocycles 5.1 Asymmetric Brønsted Acid Catalyzed Hydrogenation of ­Indoles 5.2 Asymmetric Brønsted Acid Catalyzed Hydrogenation of Benzoxazines, Benzthiazines, Benzoxazinones, Quinoxalines, Quinoxalinones and Benzodiazepinones 6 Asymmetric Organocatalytic Reduction of Pyridines 7 Asymmetric Organocatalytic Reductions in Cascade ­Sequences 8 Conclusion