A simple circular dichroism method for the determination of the absolute configuration of allylic amines

Absolute configurations of C(α)-chiral primary allylic amines can be determined from the CD spectra of their N-phthaloyl derivatives. This method is based on the exciton coupling of the allowed π–π* transitions in the phthalimide and olefin chromophores: positive helicity of the N–Cα–CC bond system results in a positive Cotton effect at ca. 220 nm, a negative Cotton effect is obtained for the negative helicity N–Cα–CC bond chain.