Synthesis of hybrid pyridine derivatives in the presence of TMIPOP as catalyst^a.

^aReaction conditions: aldehyde (1 mmol), ke3 (1 mmol, 0.370 g), 3-(1H-indol-3-yl)-3-oxopropanenitrile (1 mmol, 0.184 g) and ammonium acetate (1.5 mmol, 0.115 g), solvent-free, 110 °C, catalyst = 20 mg, reported yields are referred to isolated yields.