Preparation of methyl acrylate from methyl acetate and methanol with mild catalysis of cobalt complex

The activation and selectivity are the challenging problems always existing in the utilization of methanol as C 1 resource. Herein, a novel cobalt complex catalyzed process for preparation of methyl acrylate from methyl acetate and methanol at 50 °C–80 °C was firstly developed. Such cobalt complex stabilized with a PN 5 P-type pincer ligand, which can be easily prepared in gram scale, has high catalytic performance with the loading amount of only 5 mol.%. Systematic mechanism investigation revealed the cobalt complex activated by sodium methoxide via salt elimination could simultaneously interact with and catalyze the dehydrogenation of two-fold methanol into formaldehyde, followed by proceeding aldol condensation with methyl acetate in the presence of sodium methoxide. Besides the reaction atmosphere of O 2 was proved to be crucial for preventing the further hydrogenation of methyl acrylate into methyl propionate. Also, the mechanism-based kinetic model indicated the dehydrogenation of methanol was rate-controlling step with the activation energy of 89.0 ± 1.1 kJ/mol.