Biocatalytic Michael-Type Additions of Acetaldehyde to Nitroolefins with the Proline-Based Enzyme 4-Oxalocrotonate Tautomerase Yielding Enantioenriched γ-Nitroaldehydes
作者:Edzard M. Geertsema、Yufeng Miao、Pieter G. Tepper、Pim de Haan、Ellen Zandvoort、Gerrit J. Poelarends
DOI:10.1002/chem.201302351
日期:2013.10.18
Call me Michaelase: The enzyme 4‐oxalocrotonate tautomerase (4‐OT) promiscuously catalyzes the Michael‐type addition of acetaldehyde to a collection of aromatic and aliphatic nitroolefins with high stereoselectivity producing precursors of γ‐aminobutyric acid (GABA) analogues (see scheme).
Organocatalyst‐Mediated Dehydrogenation of Aldehydes to α,β‐Unsaturated Aldehydes, and Oxidative and Enantioselective Reaction of Aldehydes and Nitromethane Catalyzed by Diphenylprolinol Silyl Ether
作者:Yujiro Hayashi、Takahiko Itoh、Hayato Ishikawa
DOI:10.1002/adsc.201300919
日期:2013.12.16
AbstractA one‐pot transformation of aldehydes into α,β‐unsaturated aldehydes was developed using both N‐benzyl‐N‐methylamine and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) as catalysts and MnO2 as a terminal oxidant. An oxidative and enantioselective reaction of aldehydes and nitromethane was established using both diphenylprolinol silyl ether and DDQ as a catalyst with MnO2 as a terminal oxidant, in which synthetically important β‐substituted γ‐nitro aldehydes were obtained with excellent enantioselectivity.magnified image