Cobalt carbonyl ionic liquids based on the 1,1,3,3-tetra-alkylguanidine cation: Novel, highly efficient, and reusable catalysts for the carbonylation of epoxides

A series of novel cobalt carbonyl ionic liquids based on 1,1,3,3-tetra-alkylguanidine were synthesized. The catalytic performance of these compounds was investigated in the carbonylation of epoxides, with 3a exhibiting the best catalytic activity and recyclability.