Preparation of new chiral bisoxazoline ligands for the catalytic asymmetric intramolecular cyclopropanation of α-diazo-β-keto phenyl sulfone to afford a useful bicyclo[3.1.0]hexane derivative
作者:Takashi Sawada、Masahisa Nakada
DOI:10.1016/j.tetasy.2012.02.021
日期:2012.3
preparation of novel chiral bisoxazoline ligands with various substituents at the bisoxazoline linkage, for use in the catalytic asymmetric intramolecular cyclopropanation (CAIMCP) of α-diazo-β-keto phenyl-5-hexenyl sulfone to afford a simple, but useful, bicyclo[3.1.0]hexane derivative. The enantioselectivity of the CAIMCP of α-diazo-β-keto phenyl-5-hexenyl sulfone was improved and a product with 84% ee was
在本文中,我们描述了新颖的手性双恶唑啉配体的制备,该配体在双恶唑啉键上具有多个取代基,用于α-重氮-β-酮基苯基-5-己烯基砜的催化不对称分子内环丙烷化(CAIMCP),以提供简单但有用的,双环[3.1.0]己烷衍生物。改进了α-重氮-β-酮苯基-5-己烯基砜的CAIMCP的对映选择性,并使用30 mol%的催化剂(由CuOTf和新的双恶唑啉配体原位制备)获得了ee为84%的产品在双恶唑啉键上具有两个3,5-二叔丁基苄基。该产物通过一次结晶以对映体纯的形式获得,使其可用作手性构件。