Bottom-Up Synthesis of Supported Thioureas and Their Use in Enantioselective Solvent-Free Aza-Henry and Michael Additions
作者:José M. Andrés、Noelia de La Cruz、María Valle、Rafael Pedrosa
DOI:10.1002/cplu.201500476
日期:2016.1
Two sets of supported chiral thioureas, which differ in the length of the tether that connects the chiral appendage to the polymer structure and the effective functionalization, have been prepared by copolymerization of styrene, novel styryl thioureas derived from l-valine, and divinylbenzene. The efficiency of these polymeric thioureas has been tested in two different enantioselective transformations
通过苯乙烯,衍生自1-缬氨酸的新型苯乙烯基硫脲和二乙烯基苯的共聚制备了两组支持的手性硫脲,它们的连接手性附件与聚合物结构的束缚带的长度不同,并且有效官能化不同。在纯净的反应条件下,已通过两种不同的对映选择性转化,即氮杂-亨利和硝基-迈克尔反应,对这些聚合硫脲的效率进行了测试。所获得的结果表明,可以再循环硫脲,并且它们能够在低催化剂负载下以良好的对映选择性促进反应。