Chiral squaric prolinols: a new type of ligand for the asymmetric reduction of prochiral ketones by borane
作者:Ji Zhang、Hai-Bing Zhou、Shou-Mao Lü、Mei-Ming Luo、Ru-Gang Xie、Michael C.K. Choi、Zhong-Yuan Zhou、Albert S.C. Chan、Teng-Kuei Yang
DOI:10.1016/s0957-4166(01)00333-0
日期:2001.7
prolinol ligands, having N, S substituents at C(3) of the squaric ring were synthesized and applied to the asymmetric borane reduction of prochiral ketones via an in situ formed chiral boron heterocycle, affording secondary alcohols with high yields and excellent enantiomeric excesses (up to 99%). The crystal structure of 5a was obtained and the mechanism of the catalytic asymmetric reduction is also
合成了一系列在手性环的C(3)上具有N,S取代基的手性双官能方型脯氨醇配体,并将其应用于通过原位形成的手性硼杂环的不对称硼烷还原手性酮的硼烷,从而提供了高收率的仲醇和出色的对映体过量(高达99%)。获得了5a的晶体结构,并探讨了催化不对称还原的机理。