Low-Valent Iron-Catalyzed C−C Bond Formation−Addition, Substitution, and C−H Bond Activation

The use of iron as a catalyst for organic synthesis has been increasingly attracting the interest of chemists from economical and ecological points of view. While Fe(III) and Fe(II) catalysts have long been used as Lewis acids for synthesis, we have been interested in exploration of catalysis based on rather unexplored organoiron chemistry since the late 1990s. This Perspective summarizes a series of iron-catalyzed C−C bond formation reactions developed by us, which include (asymmetric) carbometalation of olefins, cross-coupling of alkyl halides, and activation of sp2 and sp3 C−H bonds.