Catalysis of Metal(II) Acetate–2,2′-Bipyridine Complexes in the Aldol Condensations

The rate of the condensation of benzaldehyde with excess acetophenone catalyzed by Co(II) acetate-2,2′-bipyridine complex was obtained by GLC analysis. The rate increased in proportion as the amount of the complex catalyst. 2,2′-Bipyridine ligand in the Co(II) complex enhanced the catalytic activity remarkably, though the ligand itself had no activity. When the molar ratio of Co(II): bpy was 1 : 1 or 1 : 2, the highest activity was observed. The activation energy of the complex (1 : 1) catalyzed reaction was calculated as 13.7 kcal/mol. The catalysis of the complex behaved like a base catalyst. Briefly, the relation of the complex catalyzed aldol condensations with the enzymatic reaction of Class II aldolase is also described.