Pyrrole-containing metal complexes widely exist in nature, for example, vitamin B12, heme, chlorophyll, and their derivatives. Each of them shows significant functions, which are essential for life. To mimic their important functions and substance conversion reactions, numerous pyrrole-containing metal complexes have been synthesized and investigated. This review mainly focuses on cobalt complexes having pyrrole-containing ligands and the recent progress of molecular transformations catalyzed by the complexes, especially the vitamin B12-related cobalt complexes and porphycene cobalt complexes. A variety of reaction systems, which enable a number of molecular transformations under mild conditions is described. The construction of new reaction systems and a combination of the materials inspired by natural systems is a promising and effective approach to realizing eco-friendly and cost-effective reaction systems.
!!!All Science Journal Classification (ASJC) codes