Catalytic arene H/D exchange with novel rhodium and iridium complexes

Article abstract of DOI:10.1021/om2012419

Three novel pendant acetate complexes, [Rh(bdmpza)Cl₃] ^-M⁺, [Rh(bdmpza)Cl₂(py)], and [Ir(bdmpza)Cl₃]^-M⁺ (bdmpza = bis(3,5-dimethylpyrazol-1-yl) acetate, M⁺ = Li⁺, Na ⁺), were synthesized. Abstraction of halide from these complexes with silver salts yielded species capable of C-H activation of arenes. The catalytic H/D exchange reaction between benzene and trifluoroacetic acid-d was optimized, and these conditions were used to evaluate H/D exchange in other arenes. Branched alkyl substituents in alkyl aromatics showed an affinity toward deuterium exchange in the β-alkyl position only. DFT calculations were performed to determine the mechanism of H/D exchange.