A novel tartrate-derived guanidine accessed by a modular approach was identified to be an efficient catalyst for the Michael addition of 3-aminooxindoles to nitroolefins. A range of quaternary 3-aminooxindoles bearing adjacent quaternary–tertiary stereocenters were obtained in good to excellent yields (up to 95%) with good to excellent diastereo- and enantioselectivities (up to >20:1 dr and 98% ee).

中文翻译：

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基于酒石酸的模块化胍的鉴定，以实现3-氨基氧吲哚向硝基烯烃的高度不对称迈克尔加成

通过模块化方法获得的一种新的酒石酸衍生的胍被认为是将3-氨基氧吲哚迈克尔加成到硝基烯烃的有效催化剂。获得了一系列具有相邻四级-三级立体中心的四级3-氨基羟吲哚，收率良好至优异（高达95％），非对映选择性和对映选择性（高达> 20：1 dr和98％ee）。