Wittig Reaction by Using DBU as a Base

The reaction of methyltriphenylphosphonium bromide with DBU in refluxing dichloromethane or toluene afforded methylenetriphenylphosphorane, which further reacted with benzaldehydes to give styrenes in good yields. Semistabilized ylide, benzylidenetriphenylphosphorane was also synthesized by using DBU, which reacted with aldehydes to afford olefins in nearly quantitative yields.