Magnetic non-equivalence in the nuclear magnetic resonance spectra of 2-cyanoethyl(phenyl)-1-phenylethylphosphine and NO-dimethyl-N-(1-phenylethyl)hydroxylamine

Abstract

Details of the n.m.r. spectra of the title compounds are reported and discussed. Both compounds show magnetic non-equivalence, and for the doubly asymmetric 2-cyanoethyl(phenyl)-1-phenylethylphosphine evidence is presented which suggests that asymmetric induction occurs during the last stage of the phosphine synthesis. With the doubly asymmetric NO-dimethyl-N-(1-phenylethyl)hydroxylamine, however, the non-equivalence was only observed below –10°(in [²H]chloroform) and the evidence to date suggests that the two diastereomeric (±)-pairs are of similar energy and therefore of equal population in the diastereomeric mixture.