A convenient route to aryl substituted chloro and bromo olefins
作者:Sudha Kumaraswamy、K.C.Kumara Swamy
DOI:10.1016/s0040-4039(97)00277-3
日期:1997.3
A wide range of aryl substitutedchloro and bromo olefins has been prepared by treating α-chloro and α-bromophosphonates derived from 1-hydrido-5,5-dimethyl-1,3,2-dioxaphosphorinane with sodium hydride in THF at 0°C followed by an aldehyde.
reaction of inexpensive α-chlorophosphonates with alkyl acrylates in the presence of sodium hydride is reported. Reaction with dimethylmaleate or fumarate also leads to cyclopropyl-substituted phosphonates. These reactions take place via Michaeladdition of acrylate, dimethylmaleate, or fumarate to the phosphonate carbanion, followed by expulsion of the chloride ion.