Computation of physical chirality: An assessment of orbital desymmetrization induced by common chiral auxiliaries

The continuous chirality measure (CCM) of Avnir is extended to treat equiamplitude surfaces of wave functions in three dimensions. By implementing this methodology, we evaluate the amount of orbital desymmetrization that is induced by common chiral auxiliaries used in asymmetric syntheses. We find that, while some chiral auxiliaries themselves have very little chirality content, the molecule as a whole to which they are attached can be very chiral and that significant orbital desymmetrization is induced by these auxiliaries. Generally, the chirality content of the frontier orbitals of these molecules is large, being comparable in magnitude to the structural chirality of the molecules themselves.