Highly enantioselective carbonyl-ene reactions catalyzed by a hindered silyl-salen-cobalt complex
Highly enantioselective carbonyl-ene reactions catalyzed by a hindered silyl-salen-cobalt complex
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DOI：
10.1021/ol071342d
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发表时间：
2007-09-27
期刊：
影响因子：
5.2
通讯作者：
Rawal, Viresh H.
中科院分区：
文献类型：
--
作者：
Hutson, Gerri E.;Dave, Apurva H.;Rawal, Viresh H.
本文报道了各种1，1-二取代和三取代烯烃与乙氧基乙酸乙酯的不对称羰基-烯反应。这些反应是由一种新的Co-Salen络合物催化的，其中大体积的三异丁基硅基(TIBS)取代基占据了与酚氧基垂直的位置。该络合物在近乎理想的条件下催化反应-在室温下，催化剂负载量低至0.1mol%-并以优异的产率、对映选择性和非对映选择性提供手性高烯丙醇产品。
We report here the enantioselective carbonyl-ene reactions of various 1,1-disubstituted and trisubstituted alkenes with ethyl glyoxylate. The reactions are catalyzed by a new Co-salen complex, in which bulky triisobutylsilyl (TIBS) substituents occupy the positions ortho to the phenolic oxygens. This complex catalyzes the reactions under nearly ideal conditions-at room temperature and using catalyst loadings as low as 0.1 mol %-and provides the chiral, homoallylic alcohol products in excellent yields, enantioselectivities, and diastereoselectivities.