Configurational stability of asymmetrically substituted organotin compounds. An example of optical activity at the tin centre

Abstract

Chemical shift non-equivalence of diastereotopic groups has been studied for a series of organotin monohalides with organic groups of different sizes to test the stereochemical stability of the asymmetric tin centre. The mutually related effects of halogen intermolecular exchange, nature of tin–halogen bond, intrinsic asymmetry of the molecules, and the steric requirements of the organotin groups are discussed in the light of the experimental findings. The effect of the bulk of the organic groups on the intrinsic asymmetry of some organotin compounds with four carbon–tin bonds has also been studied. An optically active tetraorganotin compound has been obtained through asymmetric synthesis.