NADH Models in the pyrido[2,3-b]indole series were synthesized and studied. Non chiral models allow for the first time the reduction of non activated ketones i.e acetophenone in the presence of Et₂AlCl. Despite the occurence of a reversible side aldol reaction, the yield was almost quantitative. The scope of such reactions was studied. In the presence of chiral aluminium derivatives a supramolecular effect was observed during the reduction of methyl benzoylformate. Chiral NADH models with rigidified cyclized structures at the amide part of the chiral auxiliary were synthetized by various methods. They were involved in the reduction of methyl benzoylformate. High enantiomeric excesses were obtained suggesting that the dihedral angle between the C=0 amide and the 1,4-dihydropyridine ring plays an important role in the stereodifferentiation of the two faces of the reagent.