The aza-MBH reaction of imines, e.g., I, and beta -naphthyl acrylate in the presence of C-6' modified beta -isocupreidine deriv. (0.1 equiv) and beta -naphthol (0.1 equiv) afforded the corresponding (3S)-aza-MBH adducts, e.g., II, in high yield and excellent enantiomeric excess. These catalytic conditions allowed the aliph. imines to be employed for the first time as electrophilic partners of the aza-MBH reaction. The coexistence of two H-bond donors with different acidic strengths was found to be crucial for the obsd. high enantioselectivity. [on SciFinder (R)]