Catalytic Arene H/D Exchange with Novel Rhodium and Iridium Complexes

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.

合成了三种新型的配位键醋酸复合物，分别为[Rh(bdmpza)Cl3]−M+、[Rh(bdmpza)Cl2(py)]和[Ir(bdmpza)Cl3]−M+（其中bdmpza代表双(3,5-二甲基吡唑-1-基)醋酸，M+代表Li+或Na+）。通过这些复合物与银盐的反应，可以提取出能够激活芳烃C-H键的物质。优化了苯与三氟乙酸-d之间的催化H/D交换反应，并在此条件下评估了其他芳烃的H/D交换。在烷基芳烃中，分支烷基取代基仅对β-烷基位置的氘交换表现出亲和力。为了确定H/D交换的机理，进行了DFT计算。