Halo-substituted benzenesulfonyls and benzenesulfinates: convenient sources of arenes in metal-catalyzed C-C bond formation reactions for the straightforward access to halo-substituted arenes

Palladium-catalyzed reactions using aryl halides as one of the coupling partners represent a very popular method for generating carbon-carbon bonds. However, such couplings suffer from important limitations. As most palladium catalysts are very effective for the cleavage of C-halo bonds (Halo = Cl, Br or I), in many cases, the presence of several halide functional groups on arenes is not tolerated. Since two decades, and especially during the last few years, a new class of coupling partners, benzenesulfonyl and benzenesulfinate derivatives, has emerged as a powerful alternative to aryl halides for the Pd-catalyzed C-C bond formation, as the reactions performed with these substrates generally tolerate C-halo bonds. With these substrates, after a metal-catalyzed desulfitative coupling, a variety of halo-substituted arenes such as biaryls, styrenes, phenylacetylenes, acetophenones, benzonitriles... has been synthesized with high chemoselectivities. The use of these aryl sources allowed the synthesis of molecules containing several halo-substituents including iodo-substituents in only a few steps and provides very simple access to a very wide variety of halo-substituted arenes useful to materials chemists and also to biochemists. In this review, we will summarize the scope of the use of halo-substituted benzenesulfonyls and benzenesulfinates as coupling partners in metal-catalyzed C-C bond formation.