树脂固载的β-酮砜的烷基化反应

ALKYLATION OF POLYMER-BOUND α-CARBANION OF β-KETOSULFONE

Samuelsson等由季铵盐、碱和β-酮砜化合物制得相应的β-酮砜阴离子季铵盐,可直接用于烷基化反应。此法较经典方法虽有条件温和,产率较高的优点,但分离麻烦,季铵盐用量大且不能回收.聚合物负载的季铵盐作为相转移催化剂和反应底物的载体,已用于含活泼亚甲基化合物的烷基化反应.本文用离子交换法制得了大孔季铵盐离子固载的β-酮砜阴离子试剂,探索了这种试剂的烷基化反应条件,制得了一系列β-酮砜化合物的衍生物。

Polymer-bound α-carbanion of β-ketosulfone (2) was prepared by exchange reactionof strongly basic anion resin D296 (OH- form) with α-pheny′sulfonyl acetophenone (1).Several alkylated products of 2 were synthesized under anhydrous condition by polymer-supported carbanion with alkyl halides in good yields. The hydrolysis of the ester groupin the alkylating agent could be avoided in this process.