A New Strategy for the Synthesis of Chiral β-Alkynyl Esters via Sequential Palladium and Copper Catalysis
作者:Barry M. Trost、Benjamin R. Taft、James T. Masters、Jean-Philip Lumb
DOI:10.1021/ja203171x
日期:2011.6.8
new strategy for the synthesis of chiral β-alkynyl esters which relies on sequential Pd and Cu catalysis is reported. Terminal alkynes bearing aryl, alkyl, and silyl groups can be employed without prior activation yielding a wide range of important chiral building blocks. The reaction sequence utilizes a robust Pd(II)-catalyzed hydroalkynylation of ynoates with terminal alkynes providing geometrically
报道了一种依赖连续 Pd 和 Cu 催化合成手性 β-炔基酯的新策略。可以使用带有芳基、烷基和甲硅烷基的末端炔烃,而无需事先活化,从而产生多种重要的手性结构单元。反应序列利用强大的 Pd(II) 催化的炔烃与末端炔烃的加氢炔化反应,提供几何纯的炔烃,这些炔烃很容易被 CuH 还原。与之前的报道相比,炔酸酯的添加对 1,6-途径的边缘偏爱进行,这种共轭还原以高 1,4-选择性发生,产生具有优异对映选择性水平的 β-炔基酯。重要的是,该方法可耐受多种功能,包括烯丙基碳酸酯和氨基甲酸酯,