Rh I Ar/Au I Ar′ Transmetalation: A Case of Group Exchange Pivoting on the Formation of M−M′ Bonds through Oxidative Insertion

By combining kinetic experiments, theoretical calculations, and microkinetic modeling, we show that Pf/Rf (C 6 F 5 /C 6 Cl 2 F 3 ) exchange between [AuPf(AsPh 3 )] and trans ‐[RhRf(CO)(AsPh 3 ) 2 ] does not occur by typical concerted Pf/Rf transmetalation via electron‐deficient double bridges. Instead, it involves asymmetric oxidative insertion of the Rh I complex into the (Ph 3 As)Au−Pf bond to produce a [(Ph 3 As)Au−RhPfRf(CO)(AsPh 3 ) 2 ] intermediate, followed by isomerization and reductive elimination of [AuRf(AsPh 3 )]. Interesting differences were found between the LAu−Ar asymmetric oxidative insertion and the classical oxidative addition process of H 2 to Vaska complexes.