Porphyrin has been receiving much attention in the wide area of science. Porphyrins generally accommodate a variety of metals in the central cavity. The central metal often plays a critical role to dominate electronic and structural properties of a metalloporphyrin. In contrast, porphyrins which have carbon-metal bond at the porphyrin peripheral remain unexplored. In particular, porphyrins with a peripheral carbon-transition metal σ-bond are very rare. However, we have demonstrated that borylated porphyrins are versatile synthetic intermediates for the creation of novel porphyrin derivatives. Furthermore, porphyrins with a carbon-transition metal bond have exhibited unique structural features and catalytic activity.
