A convenient preparation of mono- or gem-di-halogenoalkenes from α-sulfonyl carbanions and halogenolithiocarbenoïds
作者:Philippe Charreau、Marc Julia、Jean-Noël Verpeaux
DOI:10.1016/0022-328x(89)85159-9
日期:1989.12
Various α-sulfonyl carbanions have been shown to react at low temperature with di- or tri-halogenolithiocarbenoïds, to give 1-mono- or 1,1-di-halogenoalkenes. Bromocarbenoïds gave better results than their chloro-analogues. Reaction of di-bromolithiomethane with α-lithiated sulfones gives a high yield of vinylic bromides, the stereochemistry of which is cleanly E. Evidence is presented that the carbenoïd
已显示各种α-磺酰基碳负离子在低温下与二或三卤代低聚硫代碳烯化合物反应,生成1-单-或1,1-二卤代烯烃。溴碳二烯比其氯类似物产生更好的结果。用α-锂化砜二bromolithiomethane的反应,得到乙烯基溴化物的产量高,立体化学其中是干净Ë。有证据表明,碳烯化合物本身是反应的原因,并且没有首先转化为相应的碳烯。