Organocatalyzed Enantioselective Protonation of Silyl Enol Ethers: Scope, Limitations, and Application to the Preparation of Enantioenriched Homoisoflavones
作者:Thomas Poisson、Vincent Gembus、Vincent Dalla、Sylvain Oudeyer、Vincent Levacher
DOI:10.1021/jo101585t
日期:2010.11.19
In the present work, enantioselective protonation of silyl enol ethers is reported by means of a variety of chiral nitrogen bases as catalysts, mainly derived from cinchona alkaloids, in the presence of various protic nucleophiles as proton source. A detailed study of the most relevant reaction parameters is disclosed allowing high enantioselectivities of up to 92% ee with excellent yields to be achieved
在目前的工作中,据报道在各种质子亲核试剂作为质子源的情况下,通过多种手性氮碱作为催化剂,主要衍生自金鸡纳生物碱,对甲硅烷基烯醇醚进行对映选择性质子化。公开了对最相关的反应参数的详细研究,从而允许在温和和环境友好的条件下实现高达92%ee的高对映选择性和极佳的收率。此有机催化质子化的合成效用制备两个homoisoflavones期间展示图4a和4b中,从分离吊兰Inornatum和绵性厌食症,其分别用81%和78%ee的,获得的。