Asymmetric Direct Aldol Reaction of α-Keto Esters and Acetone Catalyzed by Bifunctional Organocatalysts
作者:Fei Wang、Yan Xiong、Xiaohua Liu、Xiaoming Feng
DOI:10.1002/adsc.200700285
日期:2007.12.10
A type of C2-symmetrical bisprolinamide has been developed for the asymmetric aldol reaction between acetone and α-keto esters, which furnishes the chiral tertiary alcohols in high yields (up to 99 %) with high enantioselectivities (up to 94 % ee). Aliphatic, heteroaromatic and aromatic α-keto esters including those with electron-donating or electron-withdrawing group substituents were found to be
已经开发出一种用于丙酮和α-酮酸酯之间的不对称醛醇缩合反应的C 2对称双脯氨酰胺,其以高收率(高达99%)和高对映选择性(高达94%ee)提供了手性叔醇。发现在双脯氨酰胺2a(15 mol%)和AcOH(150 mol%)的存在下,反应时间为零的脂肪族,杂芳族和芳香族α-酮酯(包括具有供电子或吸电子基团取代基的那些)是合适的底物。超过16小时。用容易获得的试剂可以很容易地操纵该过程。催化剂2a的几何形状在所有电子计算中,对B3LYP / 6-31G(d)进行了完全优化。基于实验研究和催化剂2a的DFT计算,提出了一种可能的过渡态A来解释活化和不对称电感的起源。