The efficient enantioselective synthesis of dihydropyrans via organocatalytic Michael addition reactions
作者:Zhiqiang Niu、Xinwei He、Yongjia Shang
DOI:10.1016/j.tetasy.2014.04.014
日期:2014.5
An asymmetric Michael addition of α-cyanoketones to α,β-unsaturated aldehydes to form chiral dihydropyrans catalyzed by l-diphenylprolinol trimethylsilyl ether is presented. A series of 3,4-dihydropyrans were obtained in excellent yields (up to 91%) and enantioselectivities (up to 98% ee). A plausible mechanism for this process is proposed.
不对称迈克尔加成α-cyanoketones的α,β不饱和醛以形成由1- diphenylprolinol三甲基甲硅烷醚催化的手性二氢吡喃被呈现。在良好的产率(高达91%)和对映选择性(高达98%ee)的条件进行,得到一系列的3,4-二氢吡喃。提出了这一进程的一个可行的机制。