An asymmetricreduction of ethyl pyruvate was carried out using bakers’ yeast cell free extract with addition of NADPH in catalytic amounts and glucose as a hydride source. The total turnover number of NADPH reached 7680. The efficiency of the cell free extract is discussed.
Synthesis of optically active 2-hydroxy monoesters via-kinetic resolution and asymmetric cyclization catalyzed by heterometallic chiral (salen) Co complex
作者:Wenji Li、Santosh Singh Thakur、Shu-Wei Chen、Chang-Kyo Shin、Rahul B. Kawthekar、Geon-Joong Kim
DOI:10.1016/j.tetlet.2006.03.042
日期:2006.5
The binuclear chiral (salen) Co complexes bearing Lewis acids of Al and Ga catalyze regio- and enantioselective ring opening of terminal epoxides with carboxylic acids. The ring opened product of epichlorohydrin with carboxylic acids followed by cyclization step in the presence of catalyst and base represent straightforward, efficient methods for the synthesis of enatiomerically enriched (>99% ee)
Bakers' yeast cell-free extract was found to reduce 1-acetoxy-2-alkanones to (S)-1-acetoxy-Z-alkanols in 59 - 88% yield and 95 - >99% ee by use of a catalytic amount of NADPH with glucose as a hydride source and without addition of any enzyme for the cofactor regeneration.
The baker's yeast reduction of 1-acetoxy-2-alkanones in the presence of a sulfur compound
Improved enantioselectivity was achieved in the baker's yeast reduction of the 1-acetoxy-2-alkanone derivatives by the addition of a sulfur compound such as L-cysteine and phenyl vinyl sulfide. The reaction rate of the baker's yeast reduction was accelerated using a sulfur compound as an additive. The migration of the acetyl group and the hydrolysis of the acetoxy group of the substrate was suppressed using a sulfur compound. (C) 1997 Elsevier Science Ltd.
Breeden, Simon; Cole-Hamilton, David J.; Foster, Douglas F., Angewandte Chemie - International Edition, 2000, vol. 39, # 22, p. 4106 - 4108
作者:Breeden, Simon、Cole-Hamilton, David J.、Foster, Douglas F.、Schwarz, Gary J.、Wills, Martin