迈克尔加成反应被广泛认为是有机合成中最普遍的CC键形成方法之一,对映选择性催化共轭加成反应的发展一直是深入研究的主题。除了金属配合物催化的巨大成功之外,近年来还深入探索了强大且环保的有机催化剂介导的不对称共轭加成反应。β-酮酯与 α,β-不饱和羰基化合物的对映选择性有机催化共轭加成反应代表了手性 1,5-二羰基化合物的直接且最吸引人的方法,手性 1,5-二羰基化合物是有机合成中的通用中间体。特别是,将 4-羟基香豆素添加到 α 中,β-不饱和酮是获取华法林的一种直接方法,华法林是一种有效的抗凝剂。进一步研究表明,(S)-华法林比 R 对映体具有更高的抗凝活性。因此,获得华法林的光学纯 R 或 S 对映异构体将非常重要。在已建立的手性华法林合成策略中,手性辅助策略、氢化和异狄尔斯-阿尔德反应已得到深入研究。最近,几个小组报道了由手性仲胺、伯胺和双功能伯胺硫脲催化的 4-羟基香豆素与烯酮的对映
A novel chiral metal‐organic framework (MOF) organocatalyst has been developed, based on readily available MIL‐101 and the chiral primary diamine (1R,2R)‐1,2‐diphenylethylenediamine, by the post‐synthetic modification. Over the developed chiral heterogeneous catalyst the asymmetric synthesis of (S)‐warfarin with high enantioselectivity can be fulfilled on a gram‐scale (2.8 g) with excellent yield (92%)
secondary amine amide catalysts were developed for the asymmetric Michaeladdition of 4-hydroxycoumarin to α,β-unsaturated ketones. A series of important biologically and pharmaceutically active compounds were obtained in excellent yields (up to 99 %) with high enantioselectivities (up to 89 % ee) under mild conditions. In addition, enantiopure product could be obtained by a single recrystallization
Chiral primary amino amide organocatalysts were designed and synthesized as new organocatalysts for the enantioselective Michael addition of 4-hydroxycoumarin with alpha,beta-unsaturated ketones to produce chiral warfarin (up to 56% ee with up to 92% yield).