-Symmetric 1,2-Diphenylethane-1,2-diamine-Derived Primary-Tertiary Diamine-Catalyzed Asymmetric Mannich Addition of Cyclic -Sulfonyl Trifluoromethylated Ketimines.

A simple chiral primary-tertiary diamine derived from -symmetric 1,2-diphenylethane-1,2-diamine as the organocatalyst in combination with the trifluoroacetic acid additive for the asymmetric Mannich reaction of cyclic sulfonyl trifluoromethylated ketimines and methyl ketones afforded the desired product with high enantioselectivity (73-96% ee). The reactions proceeded well for a variety of different substituted cyclic -sulfonyl trifluoromethyl ketimines and various alkyl methyl ketones, providing access to diverse enantioenriched benzo-fused cyclic sulfamidate -heterocycles bearing a trifluoromethylated α-tetrasubstituted carbon stereocenter. This study also investigated the diastereoselective reduction of the carbonyl group and ring cleavage reduction of the sulfamidate group of the corresponding Mannich product.