and oxalyl chloride or thionyl chloride, works as a versatile acid activator reagent for the direct [2+2] ketene–imine cycloaddition of substituted acetic acid and imines in one-pot synthesis under mild conditions. Monocyclic, spirocyclic and 3-electron-withdrawing group β-lactams were synthesized by this method and optimization of conditions were performed.
(
氯亚甲基)二甲基
氯化铵(Vilsmeier试剂),可以轻松地由N,N-二甲基甲酰胺和
草酰氯或亚
硫酰氯制备,可作为通用的酸活化剂,用于直接[2 + 2]烯酮-
亚胺环加成取代的
乙酸和
亚胺在温和条件下一锅合成。用该方法合成了单环,螺环和3个吸电子基β-内酰胺,并进行了条件优化。