Vinyltriphenylphosphonium Salt-mediated New Synthesis of Functionalized Maleimides
Abstract
N-Methyl-2-chloroacetoacetamide undergoes a complex reaction with dialkyl acetylenedicarboxylates and triphenylphosphine to produce dialkyl 2-(N-methyl-2-chloroacetoacetamide-2-yl)-3-(triphenylphosphoranylidene)-butanedioates, which undergo elimination-cyclization reactions to produce N-methyl-4-acetyl-3-(alkoxycarbonyltriphenylphosphoranylidene)-maleimides.