In situ N-alkylation of azlactones (1,3-oxazol-5(4H)-ones) with reactive alkylating agents has been successfully accomplished. The resulting mesoionic 1,3-oxazolium 5-oxides (munchnones) are further transformed into N-alkylated pyrroles via a 1,3-dipolar cycloaddition reaction with a dipolarophile (dimethyl acetylenedicarboxylate) in the presence of 2,6-di-tert-butylpyridine.
已成功实现对azlactones(1,3-
噁唑-5(4H)-酮)进行原位N-烷基化,与活性烷基化剂反应。所得的介铃状1,3-
噁唑鎓氧化物(munchnones)进一步通过与双极受体(
乙炔二
羧酸二甲酯)在
2,6-二叔丁基吡啶存在下进行1,3-双极环加成反应转化为N-烷基化
吡咯。