The application of pressure to the cycloaddition between a 1,3-diene 1 and a dihalogenophosphine2 both reduces the reaction time from days to hours and produces the cycloadduct, a P-halogenophospholenium salt 3 is finely-divided form, which readily undergoes elimination to give the phosphole 4.
对 1,3-二烯 1 和二卤代膦 2 之间的环化反应施加压力,既可将反应时间从数天缩短至数小时,又可产生环化产物--细小的 P-卤代
磷鎓盐 3,它很容易发生消除反应,生成
磷孔 4。