Novel Thiourea-Based Bifunctional Organocatalysts and Their Applications in Asymmetric Catalysis

对映体纯有机化合物的重要性日益增加。例如，越来越多的旋光性药物被引入市场，要么作为新药，要么作为“外消旋开关”的结果。因此，在过去的十年里，开发不对称反应，从简单和容易获得的试剂中获得光学活性化合物一直是人们关注的焦点。除了基于金属的不对称催化外，小有机分子催化的对映选择性转化近年来受到越来越多的关注。特别是，含硫脲（或尿素）基团的有机催化剂是深入研究的主题。硫脲（或尿素）NHs与反应物的双氢键相互作用已被普遍认识到在（硫）脲基催化中起核心作用。第二个官能团的加入是对（硫）尿素催化反应范围的又一次飞跃。双功能硫脲-胺或硫脲-醇催化剂的设计和应用取得了很大进展。

Enantiomerically pure organic compounds are gaining continuously in importance. For example, more and more optically active Pharmaceuticals are introduced to the market, either as new drugs or as the result of a "racemic switch". Therefore, the development of asymmetric reactions that afford optically active compounds from simple and readily available reagents has been of ongoing interests over the past decade(s). Apart from metal-based asymmetric catalysis, small organic molecules-catalyzed enantioselective transformations have received increasing attention over the past years. In particular, organocatalysts bearing a thiourea (or urea) group are the subjects of intensive research. The double hydrogen-bonding interaction of the thiourea (or urea) NHs and the reactant has been generally realized to play the central role in (thio)urea-based catalysis. The incorporation of a second functional group has been another leap forward with regard to the scope of reactions amenable to (thio)urea catalysis. Great progress has been made in the design and applications of e.g. bifunctional thiourea-amine, or thiourea-alcohol catalysts.