SYNTHESIS OF SOME FUNCTIONALIZED PHOSPHINOCARBOXYLIC ACIDS

Abstract

Abstract Various functionalized phosphinocarboxylic acids have been prepared by a number of complementary methods. Reactions of relatively electron-poor secondary phosphides with electron-rich halocarboxylates in liquid ammonia give high yields of phosphinocarboxylates. The substitution reaction may proceed by a classical SN 2 mechanism or by an SN rad mechanism. Reduction of the carboxylate can be a deleterious side reaction in the preparation of phosphinoacetic acids. Several phosphinopropionic acids are prepared by the Michael addition of diphenylphosphine to unsaturated esters. A valuable method proved to be the reaction of dichlorophosphinoacetic ester with functionalized organometallic reagents.