Rh(III)- and Ir(III)-catalyzed direct C-H bond transformations to carbon-heteroatom bonds

The direct manipulation of C-H bonds is now a powerful tool in chemical synthesis. In achieving the current high standard of research progresses, Rh(III) and Ir(III) complexes played an important role to understand the nature of C-H bond activation. While numerous stoichiometric reactions of hydrocarbons with Rh (III) or Ir(III) complexes were scrutinized, their use in catalytic transformations has been relatively undeveloped until recently. Given their outstanding reactivity in C-H activation, they are highly promising candidates for inducing mild C-H functionalizations. In spite of a short development history, numerous contributions from leading research groups made big strides in highly efficient and selective C-H bond transformations for the C-C and C-heteroatom bond formation. In this report, we specifically focus on the Rh(III)- or Ir(III)-mediated direct C-H functionalizations for the C-heteroatom bond formation that is now a rapidly growing area. This report presents the current status of such catalytic systems including scope of substrates and coupling partners as well as brief mechanistic descriptions.