New strategic reactions for organic synthesis:: Catalytic asymmetric C-H activation α to oxygen as a surrogate to the aldol reaction
New strategic reactions for organic synthesis:: Catalytic asymmetric C-H activation α to oxygen as a surrogate to the aldol reaction
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DOI：
10.1021/jo034533c
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发表时间：
2003-08-08
影响因子：
3.6
通讯作者：
Jin, QH
中科院分区：
文献类型：
--
作者：
Davies, HML;Beckwith, REJ;Jin, QH
用类羰基铑诱导的C-H插入对硅基醚的C-H活化是一种立体选择性合成硅基保护羟基酯的直接方法。该反应具有很高的区域选择性、非映体选择性和对映体选择性，是醛醇反应的替代品。该反应由脯氨酸铑络合物Rh-2（S-DOSP）催化(4)。高化学选择性的一个关键要求是使用供体/受体取代的类碳化合物，例如源自甲基芳基重氮乙酸酯的类碳化合物。可使用一系列的硅醚，如烯丙基硅醚、四烷氧基硅烷和简单三甲基硅烷基醚。一般来说，C-H活化优先发生在亚甲基位点，因为反应性是由空间和电子效应之间的微妙平衡控制的。
The C-H activation of silyl ethers by means of rhodium carbenoid-induced C-H insertion represents a very direct method for the stereoselective synthesis of silyl-protected -hydroxy esters. The reaction can proceed with very high regio-, diastereo-, and enantioselectivity and represents a surrogate to the aldol reaction. The reaction is catalyzed by the rhodium prolinate complex Rh-2(S-DOSP)(4). A critical requirement for the high chemoselectivity is the use of donor/acceptor-substituted carbenoids such as those derived from methyl aryldiazoacetates. A range of silyl ethers may be used such as allyl silyl ethers, tetraalkoxysilanes, and ebetaven simple trimethylsilyl alkyl ethers. In general, C-H activation preferentially occurs at methylene sites, as the reactivity is controlled by a delicate balance between steric and electronic effects.