
%0 Journal Article
%A Byrne, LT 
%A Harrowfield, JM 
%A Hockless, DCR 
%A Peachey, BJ 
%A Skelton, BW 
%A White, AH 
%T Calixarene Phosphorylation: Cation Control of Reaction Pathways
%J Australian Journal of Chemistry
%D 1993/11/01
%V 46
%N 11
%P 1673-1683
%K 
%R https://doi.org/10.1071/CH9931673
%U https://www.publish.csiro.au/paper/CH9931673 
%X The hydroxide ion catalysed phosphorylation of p-t- butylcalix [4] arene by diethyl chlorophosphate under heterogeneous conditions shows a marked sensitivity to the nature of the phase transfer catalyst used. Thus, substitution of tetraethylammonium bromide for the tetrabutylammonium bromide prescribed for the synthesis of the calixarene tetraphosphate leads to a major reaction product becoming a bis (phosphate) in which the calixarene binds as a unidentate  ligand to one phosphorus and as a bidentate ligand to the other. An X-ray crystal structure analysis on this new compound shows the calixarene to adopt a somewhat distorted 'cone' conformation with an unusual orientation of one of the t-butyl substituents into the cone cavity. It also reveals that a significant diastereoselectivity must operate in the formation reaction. The only other reaction product detected in this system appears to be the calixarene  tetraphosphate in a partial cone conformation. 
