Optically pure (R) allylic alcohols and (R) 4-phenylbutan-2-ols were prepared via oxidative kinetic resolution using whole cells of Candida papapsilosis ATCC 7330.
Enantioselective reduction of α,β-enones using an oxazaborolidine catalyst generated in situ from a chiral lactam alcohol
作者:Yasuhiro Kawanami、Yudai Mikami、Kazuya Kiguchi、Yuki Harauchi、Ryo C. Yanagita
DOI:10.1016/j.tetasy.2011.10.018
日期:2011.11
The oxazaborolidine catalyst prepared in situ from the chiral lactam alcohol 3 and 4-iodophenoxyborane was found to catalyze the enantioselective reduction of α,β-enones at −40 °C with a high level of enantioselectivity of up to 90% ee.
oxidation of allylicalcohols is challenging to perform in a chemo- as well as stereo-selective fashion at the expense of molecular oxygen using conventional chemical protocols. Here, we report the identification of a library of flavin-dependent oxidases including variants of the berberine bridge enzyme (BBE) analogue from Arabidopsis thaliana (AtBBE15) and the 5-(hydroxymethyl)furfural oxidase (HMFO) and
The first catalytic enantioselective 1,2-reduction of enones with 0.45 mol equiv potassium borohydride solution catalyzed by a chiralN,N′-dioxide–Sc(III) complex catalyst was accomplished under mild reaction conditions. A number of optically active allylic alcohols were obtained in good to excellent enantioselectivities (up to 95% ee) with nearly quantitative yields.
of enantioenriched (hetero)aromatic secondary allylic alcohols has been synthesized through deracemization of the corresponding racemic mixtures combining a non-selective chemoenzymatic oxidation (laccase from Trametes versicolor and oxy-radical TEMPO) and a stereoselective biocatalyzed reduction (lyophilized cells of E. coli overexpressing an alcoholdehydrogenase, ADH). Both steps were performed in