Chiral Tertiary Amine/L-Proline Cocatalyzed Enantioselective Morita–Baylis–Hillman (MBH) Reaction
作者:Hongying Tang、Guofeng Zhao、Zhenghong Zhou、Peng Gao、Liangnian He、Chuchi Tang
DOI:10.1002/ejoc.200700794
日期:2008.1
cocatalytic reactions with the two enantiomers of chiral amine 4 and L-proline revealed that it is the proline stereochemistry that determines the configuration of the newly formed chiral center. In addition, the existence of the free hydroxy group in amine 4a enhanced the enantioselectivity of the reaction. Based on these findings, a plausible mechanism for this cocatalytic MBH reaction has been proposed
从容易获得的手性来源开始,已经合成了四种类型的手性胺。已发现这些手性胺与 L-脯氨酸结合是甲基乙烯基酮 (MVK) 和芳香醛之间不对称 Morita-Baylis-Hillman (MBH) 反应的有效助催化剂。相应的加合物以合理的化学产率和良好的对映选择性(高达 83% ee)形成。此外,与手性胺 4 和 L-脯氨酸的两种对映异构体的平行共催化反应表明,脯氨酸立体化学决定了新形成的手性中心的构型。此外,胺4a中游离羟基的存在提高了反应的对映选择性。基于这些发现,已经提出了这种助催化 MBH 反应的合理机制。