Catalytic Enantioselective Alkylations of Tetrasubstituted Olefins. Synthesis of All-Carbon Quaternary Stereogenic Centers through Cu-Catalyzed Asymmetric Conjugate Additions of Alkylzinc Reagents to Enones
作者:Alexander W. Hird、Amir H. Hoveyda
DOI:10.1021/ja0553811
日期:2005.11.1
A method for Cu-catalyzed asymmetric conjugate addition (ACA) of dialkylzinc reagents to tetrasubstituted five- and six-memberedcyclicenones that afford quaternary all-carbon stereogenic centers in up to 95% ee is reported. Catalytic ACAs are practical and efficient. Reactions proceed to >98% conversion in undistilled commercial grade toluene in the presence of 2 mol % of an air-stable Cu salt (CuCN)
报道了一种将二烷基锌试剂与四取代的五元和六元环烯酮进行 Cu 催化不对称共轭加成 (ACA) 的方法,该方法可提供高达 95% ee 的四元全碳立体中心。催化 ACA 实用且高效。在 2 mol% 的空气稳定铜盐 (CuCN) 和易于获得的手性配体存在下,在未蒸馏的商业级甲苯中,反应进行到 >98% 的转化率。对映选择性 ACA 反应可提供易于功能化的产物,以提供各种具有高光学纯度的合成通用化合物。