Nucleophilic ring opening of trans-2,3-disubstituted epoxides to -amino alcohols with catalyst-controlled regioselectivity

We report the nucleophilic ring opening of unsymmetrical trans-epoxides to -amino alcohols with catalyst-controlled regioselectivity. This cationic aluminum salen catalyst, which contains bulky mesityl groups in the ortho-position of the phenoxide and a 2,2-diamino-1,1-binaphthalene backbone, transforms a variety of epoxides with high regioselectivity using nitrogen-containing nucleophiles. Unlike most reports, in which regioselectivity is substrate controlled, the regioselectivity in this system is catalyst controlled and allows selective nucleophilic ring opening of unbiased trans-epoxides.