Catalytic C-H functionalization by metalloporphyrins: recent developments and future directions.

Metalloporphyrins are a class of versatile catalysts with the capability to functionalize saturated C-H bonds via several well-defined atom/group transfer processes, including oxene, nitrene, and carbene C-H insertions. The corresponding hydroxylation, amination, and alkylation reactions provide direct approaches for the catalytic conversion of abundant hydrocarbons into value-added functional molecules through C-O, C-N, and C-C bond formations, respectively. This tutorial review describes metalloporphyrin-based catalytic systems for the functionalization of different types of sp(3) C-H bonds, both inter- and intramolecularly, including challenging primary C-H bonds. Additional features of metalloporphyrin-catalyzed C-H functionalization include unusual selectivities and high turnover numbers.