Highly enantioselective direct conjugate addition of ketones to nitroalkenes promoted by a chiral primary amine-thiourea catalyst
Highly enantioselective direct conjugate addition of ketones to nitroalkenes promoted by a chiral primary amine-thiourea catalyst
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DOI：
10.1021/ja0620890
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发表时间：
2006-06-07
影响因子：
15
通讯作者：
Jacobsen, Eric N.
中科院分区：
文献类型：
--
作者：
Huang, Hongbing;Jacobsen, Eric N.
伯胺硫脲衍生物1是一种活性高、对映选择性好的催化剂，可催化酮与硝基烯烃的共轭加成反应。描述了广泛的底物范围，带有芳香族或脂肪族取代基的硝基烯烃和多种酮被证明是有用的反应伙伴。乙基酮优先反应，生成带有甲基立体中心的反式产物，具有良好的非对映选择性。一个烯胺机制表明，与合作激活的亲电试剂的硫脲和酮的伯胺。
Primary amine−thiourea derivative1is an active and highly enantioselective catalyst for the conjugate addition of ketones to nitroalkenes. Broad substrate scope is described, with nitroalkenes bearing either aromatic or aliphatic substituents and a wide variety of ketones shown to be useful reacting partners. Ethyl ketones react preferentially, generating anti products with methyl-bearing stereocenters with good-to-excellent diastereoselectivity. An enamine mechanism is indicated, with cooperative activation of the electrophile by the thiourea and of the ketone by the primary amine.