Highly Enantioselective Synthesis
of α-Diazo-β-hydroxy Esters Using a Bifunctional
Titanium Complex
作者:Xiaoming Feng、Wentao Wang、Ke Shen、Xiaolei Hu、Jun Wang、Xiaohua Liu
DOI:10.1055/s-0029-1217322
日期:——
A bifunctional titanium catalyst system has been developed for the asymmetric direct-type aldol reaction of ethyl diazo-acetate with aldehydes, which produced the desired products in good yields (up to 83%) with excellent enantioselectivities (up to 94% ee). A wide range of aromatic, heteroaromatic and aliphatic aldehydes were found to be suitable substrates in the presence of (S)-BINOL (5 mol%), cinchonine
已经开发了一种双功能钛催化剂体系,用于重氮乙酸乙酯与醛的不对称直接型羟醛反应,以良好的收率(高达 83%)和优异的对映选择性(高达 94% ee)生产所需的产物。在 (S)-BINOL (5 mol%)、辛可宁 (5 mol%)、Ti(Oi-Pr) 4 (5 mol%) 存在下,广泛的芳香族、杂芳香族和脂肪族醛被发现是合适的底物和 H 2 O (15 mol%)。在实验结果和之前的报告的基础上,提出了一种可能的工作模型来解释激活和不对称感应的起源。