Stereoselective Preparation of Enol Silyl Ethers via Formation of Vinylcopper Species by Silyl Migration

本研究发展了一种多组分偶联立体选择性合成烯醇硅醚的新方法。 该方法是基于从sp2碳到烯醇化氧的Brook-type傻迁移作为关键反应的乙烯基铜物种的形成。 由此形成的烯醇式醚的立体化学由环状硅酸酯中间体的形成控制。 因此，发现α，β-不饱和酰基硅烷、吉尔曼试剂（或格氏试剂/ t-BuOCu）和有机卤化物的三组分偶联立体选择性地产生二取代烯醇甲硅烷基醚。 本发明的方法在概念上不同于依赖于通过酮的去质子化立体选择性地形成烯醇化物的常规方法。

In the present research, a mew synthetic methodology using multi-component coupling has been developed for stereoselective preparation of enol sily ethers. The process is based on the formation of vinyl copper species by the Brook-type silly migration from sp2 carbon to enolate oxygen as a key reaction. The stereochemistry of the enol silly ethers thus formed is controlled by the formation of the cyclic silicate intermediates. Thus, it was found that the three-component coupling of alpha, beta-unsaturated acylsilanes, the Gilman reagents (or the Grignard reagents / t-BuOCu), and organic halides produced disubstituted enol silyl ethers stereoselectively. The present method is different in concept to conventional methods which rely on stereoselective formation of enolates by deprotonation of ketones.