使用手性相转移催化剂的不对称烷基化反应

本文报道了用七种手性相转移催化剂(其中三种未见文献报道)催化氯化苄或溴丁烷对α-异丙基对氯苯乙腈或α-异丙基苯乙腈的不对称烷基化反应。考察了反应时间、温度、催化剂浓度和溶剂的极性等因素对不对称反应的影响。不对称烷基化产物的最大e.e.值达41.5%, 由比旋光度和带手性柱的气相色谱法测得。

Asymmetric alkylation mediated by chiral phase-transfer catalysts

Seven chiral phase-transfer catalysts, e.g., N-benzylquininium chloride and N-benzylcinchoninium chloride have been prepared and applied to the asym. alkylation of a-isopropylbenzyl cyanide and a-isopropyl-p-chlorobenzyl cyanide. The result showed that short reaction time, low temperature, high catalyst concentration and non-polar solvent would improve the optical yield. The influence of structure on the catalyst on the asym. reaction was preliminarily studied. The optical purity of the products was evaluated by gas chromatog. with a chiral column.