Organocatalytic Enantioselective Cycloetherifications Using a Cooperative Cation-Binding Catalyst
作者:Amol P. Jadhav、Jeong-A Oh、In-Soo Hwang、Hailong Yan、Choong Eui Song
DOI:10.1021/acs.orglett.8b02240
日期:2018.9.7
A highly enantioselective cycloetherification strategy for the straightforward synthesis of enantioenriched tetrahydrofurans, tetrahydropyrans, and oxepanes using Song’s cation-binding oligoEG catalyst and KF as the base is demonstrated. A wide range of ε-, ζ-, and η-hydroxy-α,β-unsaturated ketones were cyclized to the corresponding five-, six-, and seven-membered chiral oxacycles with high enantiopurity
展示了一种高度对映体选择性的环醚化策略,该策略可使用Song的阳离子结合寡聚EG催化剂和KF作为碱直接合成富对映体的四氢呋喃,四氢吡喃和氧杂环丁烷。各种各样的ε-,ζ-和η-羟基-α,β-不饱和酮被环化成具有高对映体纯度的相应的五元,六元和七元手性氧杂环。这种非常成功的催化作用可归因于由手性催化剂,底物和KF原位生成的密闭超分子手性笼中的系统协同阳离子结合催化。