Kinetic resolution of 1,1′-binaphthyl-2,2′-diamine derivatives by chiral calcium phosphate-catalyzed acylation

Abstract

1,1′-Binaphthyl-2,2′-diamine (BINAM) is a useful axially chiral compound. The kinetic resolution of BINAM is one of the most crucial methods for synthesizing chiral BINAM. We have developed a chiral calcium phosphate-catalyzed kinetic resolution of BINAM by utilizing an acylation reaction to produce a mono-amide. The kinetic resolution of BINAM derivatives was achieved by using isobutyric anhydride in the presence of chiral calcium phosphate and 4-morpholinopyridine with up to s = 127. 6,6′-Substituted BINAM derivatives were also applicable for this reaction. The resulting mono-acylated BINAM could be transformed into BINAM by hydrolysis under acidic conditions.