Apicophilicity of the ethylthio-group in trigonal bipyramidal phosphoranes

Abstract

The variable-temperature n.m.r. spectra of a number of five-co-ordinate spirophosphoranes having P-ethoxy- and P-ethylthio-groups have given data on the energetics of the pseudorotation processes available to the systems. It is concluded that the apicophilicities of ethoxy- and ethylthio-groups are similar. The spirophosphoranes were obtained from 2-substituted 1,3,2-dioxaphospholans by addition to biacetyl, 3-benzylidenepentane-2,4-dione, or 2-phenylacrylophenone, or by condensation with 1,2-diols in the presence of N-chlorodi-isopropylamine.