RhIAr/AuIAr′ Transmetalation: A Case of Group Exchange Pivoting on the Formation of M−M′ Bonds through Oxidative Insertion

Abstract

By combining kinetic experiments, theoretical calculations and microkinetic modelling, we show that the Pf/Rf (C6F5/C6Cl2F3) exchange between [AuPf(AsPh3)] and trans-[RhRf(CO)(AsPh3)2] does not occur through the typical concerted Pf/Rf transmetalation via electron deficient double bridges. Instead, it involves asymmetric oxidative insertion of the RhI complex into the (Ph3As)Au–Pf bond producing a [(Ph3As)Au–RhPfRf(CO)(AsPh3)2] intermediate, followed by isomerization and reductive elimination of [AuRf(AsPh3)]. Interesting differences are found between the LAu–Ar asymmetric oxidative insertion and the classical oxidative addition process of H2 to Vaska's complexes.