Functionalization of C-H Bonds via Metal-Catalyzed Desulfitative Coupling: An Alternative Tool for Access to Aryl- or Alkyl-Substituted (Hetero)arenes

In recent years, palladium-catalyzed direct arylation of (hetero)aromatics with aryl halides via a C-H bond activation has become a popular method for generating carbon-carbon bonds; however, such couplings still suffer from several limitations due to the limited functional group tolerance, the lack of regioselectivity of some of these couplings, or the poor reactivity of some substrates. For example, the presence of several halide functional groups on arenes is often not tolerated. In recent years, several new alternative coupling partners have been successfully employed for such couplings, such as RSO2R' derivatives using Pd or Ru catalysts to afford, after a desulfitative coupling, a variety of biaryls or alkylated arenes which in several cases cannot be obtained using aryl or alkyl halides as the coupling partners. This methodology allows the synthesis of complex molecules in only a few steps and will certainly give simpler access to a very wide variety of new biaryls or alkylated arenes useful to material chemistry and also to biochemists in coming years.