Direct C-H Transformation via Iron Catalysis

A compiled analysis and discussion of advances in iron-catalyzed C-H transformations in the past decade is presented. For the oxidation of cyclohexane, simpler and more efficient system were reported by using catalytic amounts of commercial available iron salts in acetonitrile under mild conditions, and H2O2 as the oxidant. In 2008, Fu and co-workers reported the first example of iron-catalyzed amidation of C-H bonds and a new C-N formation process was demonstrated by Li in 2010. In 2008, Nakamura and co-workers developed the first iron-catalyzed direct arylation of aryl C-H bonds with in situ generated organozinc reagents from aryl Grignard reagents and ZnCl2 in the presence of a proper ligand. Among direct C-H transformations, general alkyl sp3 C-H faces the highest challenge due to its intrinsic inactivating features.