Organocatalytic asymmetric reaction cascade to substituted cyclohexylamines

We report a new strategy for organocatalytic cascade reactions. Accordingly, enamine catalysis, iminium catalysis, and Brønsted acid catalysis can work in concert in a highly enantioselective organocatalytic cascade sequence toward chiral cis-3-substituted cyclohexylamines. We found that an achiral amine in combination with a catalytic amount of a chiral Brønsted acid can accomplish an aldol addition-dehydration-conjugate reduction-reductive amination to provide potential intermediates of pharmaceutically active compounds in good yields and excellent enantioselectivities.