Chiral recognition in phosphinic acid dimers

Abstract

A theoretical study of chiral recognition in the minimum and proton transfer transition state structures of 15 pairs of chiral phosphinic acid dimers was carried out using DFT and MP2 methods, up to the MP2/6-311++G(3df,2p) level. The proton transfer proceeds via a concerted pathway in all cases studied. Even though these complexes show high interaction energies, of the order of 120 kJ mol-1, and short interatomic HB distances, our results show small energy differences between the homochiral (RR or SS) and the heterochiral dimers (RS or SR) both in the equilibrium configuration and in the proton transfer transition state owing to the disposition of the nonoxygen substituents of the phosphorus atom as proved with additional model complexes. Copyright © 2005 John Wiley & Sons, Ltd.