Fixation of CO with Epoxides Catalyzed by Pincer-Type Azo-Aromatic Complexes of Cobalt as Catalysts.

Employing a series of azo-aromatic pincer-type cobalt(II) complexes, -, and an imine-based cobalt complex, , a highly efficient catalytic protocol for the cycloaddition of CO with epoxides at low pressure of CO is reported. The electron-withdrawing group-substituted ligands containing complexes and were most efficient. The catalytic protocol with involved a synergistic participation of an azo-aromatic catalyst (0.