low enantioselectivity, whereas sodium borohydride promotes 1,2-reduction, affording 3-piperidinylcarbonyl-1,2,4-trimethyl-1,2-dihydroquinoline () as the sole product in a moderate enantioselectivity. When 1 was reduced by the chiralNADHmodelcompound, 2,4-dimethyl-3-(N-alpha-methylbenzylcarbamoyl)-1-propyl-1,4-dihydropyridine (Me(2)PNPH (4)), the regioselectivity and enantioselectivity of the reaction