Relative apicophilicities of alkyl and aryl groups in quinquecovalent phosphoranes

Abstract

Variable temperature n.m.r. data on the perfluorobiacetyl adducts of phenyl dialkyl- and alkylaryl-phosphinites and on 6-substituted 1,5,7,11-tetraoxa-6-phosphaspiro[5.5]undecanes show that the greater compression at the apical, as opposed to the equatorial, positions in trigonal bipyramidal phosphoranes plays a large part in determining the relative apicophilicities of alkyl and aryl groups in these systems, and that the apicophilicities of methyl and phenyl groups are more similar than previous data had indicated.