Induced circular dichroism in chiral N -methyl amides possessing an achiral binaphthyl chromophore and its application to absolute configuration determination of aliphatic chiral amines

Induced circular dichroism (ICD) was observed in binaphthyl N-methyl amides of chiral primary amines. The CD spectra showed split curves centered at 225nm. A good correlation was found between the sign of the exciton chirality of the binaphthyl derivative and the absolute configuration of the original amine. Furthermore, the screw sense of the two naphthyl groups in the most stable conformer obtained from molecular mechanics (MM) calculation was in agreement with those expected from the exciton chirality, indicating that the method based on MM calculations can be used to determine unknown absolute configurations of aliphatic chiral amines. The practical use of the present method was demonstrated by the determination of the absolute configurations of the natural products, d- and l-cycloserines.