Dynamic Kinetic Resolution of Alkenyl Cyanohydrins Derived from α,β-Unsaturated Aldehydes: Stereoselective Synthesis of <i>E</i>-Tetrasubstituted Olefins
作者:Jadab Majhi、Ben W. H. Turnbull、Ho Ryu、Jiyong Park、Mu-Hyun Baik、P. Andrew Evans
DOI:10.1021/jacs.9b04384
日期:2019.7.31
A novel dynamic kinetic resolution (DKR) of tetrasubstituted alkenyl cyanohydrins prepared from the corresponding α,β-unsaturated aldehydes is described. The deprotonation of a geometrical mixture of tetrasubstituted alkenyl cyanohydrins with sodium diisopropylamide (NaDA) enables the equilibration of the E- and Z-olefins and the selec-tive functionalization of former to selectively afford the E-adduct
描述了由相应的 α,β-不饱和醛制备的四取代烯基氰醇的新型动态动力学分辨率 (DKR)。四取代的烯基氰醇与二异丙基氨基钠 (NaDA) 的几何混合物的去质子化能够实现 E-和 Z-烯烃的平衡以及前者的选择性官能化以选择性地提供 E-加合物。理论研究表明,碱金属阳离子的性质是降低两种几何异构体之间相互转化势垒的关键因素,这为 DKR 反应提供了机理基础。此外,