聚偏二氯乙烯负载金鸡纳碱催化剂的合成及其对不对称Michael反应的催化性能

将天然的金鸡纳碱——辛可宁与聚偏二氯乙烯进行接枝反应,制备了聚偏二氯乙烯负载辛可宁的催化剂.将制备的催化剂用于催化不对称Michael反应,并探索了溶剂、催化剂用量、温度、底物等不同条件对其催化性能的影响.结果表明,该催化剂在甲苯中有很高的催化活性和较好的立体选择性,Michael反应中部分产率达到80%以上,e.e值达到72%,且该催化剂具有一定的重复使用性能.

PVDC-SUPPORTED CATALYSTS DERIVED FROM CINCHONA ALKALOIDS FOR ASYMMETRIC MICHAEL REACTIONS

New polymer-supported catalysts were developed by common synthetic polymer poly(vinylidene chloride)(PVDC) grafting with natural cinchona alkali——cinchonine.Seven polyvinylidene chloride-bound catalysts were synthesized by cinchonine which activated by p-toluenesulfonyl chloride reacted with polyvinylidene chloride——polyamine resin.And they were tested in the challenging conjugate Michael addition between 1,3-dicarbonyl compounds and N-benzylmaleimide,forming quaternary carbon and tertiary carbon centers.After the investigation of solvent,amount of catalyst and temperature,the optimal catalyst PVDC-tetraethylenepentamine-cinchonine(PVDC-TEPA-CN) obtained good yield(80%),excellent enantioselectivity(72%) and diastereoselectivity(80∶20) at the optimized reaction conditions which were toluene medium,10 mol% catalyst and room temperature.In addition,the catalyst which was applied to six kinds of challenging substrates had a wide scope of substrates,and it can be recovered and reused for at least 3 cycles without loss of its enantioselectivity.