Easily accessible benzamide-derived P,O ligands (Bphos) for palladium-catalyzed carbon-nitrogen bond-forming reactions

Easily accessible benzamide-derived hemilabile phosphine ligands were efficiently prepared through ortho-directed lithiation of the corresponding NN-diethylbenzamide followed by quenching with chlorodialkylphosphines. These structurally simple hemilabile ligands were found to be highly effective in palladium-catalyzed amination of aryl and heteroaryl chlorides. Various sterically congested and functionalized aryl halide substrates were compatible in these reaction conditions. By using optimized reaction conditions, remarkable catalyst productivity (total turnover number up to 8400) was obtained.