The mechanism of the reaction between trialkyl phosphites and halogenoacetylenes

Abstract

Experiments in which alcohols are used to trap reactive intermediates suggest that the reactions between trialkyl phosphites and halogenoacetylenes, which yield ethynylphosphonates, proceed largely by initial displacement of acetylide ion from halogen by the nucleophilic phosphite. The mixed phosphate/phosphonate, diethyl 1-(diethoxyphosphono)ethyl phosphate, is one of the products formed when triethyl phosphite reacts with bromoethynylbenzene in hot acetic acid.