Carbon−Halide Oxidative Addition and Carbon−Carbon Reductive Elimination at a (PNP)Rh Center

An unsaturated (PNP)Rh fragment can be generated by means of C−C reductive elimination from (PNP)Rh(Me)(Ar) or (PNP)Rh(Ar)(Ar). This fragment undergoes carbon−halogen oxidative addition with aryl chlorides, bromides, and iodides at room temperature. The C−H oxidative addition products in reactions with haloarenes are not observed, and evidence is presented that carbon−halogen oxidative addition is thermodynamically preferred. C−C reductive elimination from (PNP)Rh(Me)(Ar) and (PNP)Rh(Ar)(Ar) proceeds near quantitatively as a clean, first-order reaction.