
%0 Journal Article
%A Brophy, JJ 
%A Gallagher, MJ 
%T Phosphonium salts. I. The alkaline hydrolysis of some bis-phosphonium salts
%J Australian Journal of Chemistry
%D 1969/07/01
%V 22
%N 7
%P 1385-1398
%K 
%R https://doi.org/10.1071/CH9691385
%U https://www.publish.csiro.au/paper/CH9691385 
%X Ethane- and ethene-1,2-bisphosphonium salts are cleaved by alkali into a phosphine and a phosphine oxide with loss of the two-carbon bridge. When the phosphorus atom carries benzyl substituents, loss of the benzyl groups is competitive with loss of the bridge.     Based on a kinetic study, a synchronous mechanism, analogous to the alkaline hydrolysis of acyclic monophosphonium salts, is proposed to account for the fragmentation.     With 6-membered 1,4-diphosphonio heterocyclic salts the nature of the products is dependent on whether alkali or phosphonium salt is present in excess. With an excess of alkali a synchronous mechanism again appears to operate, while with an excess of salt the reaction proceeds stepwise and without loss of the bridge. A partial explanation of these facts is advanced in terms of non-bonded interactions in the intermediate phosphoranes.     The synchronous reaction appears to be favoured by coplanarity of the P-C-C-P system. 
