Rh^IAr/Au^IAr′ 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 modeling, we show that Pf/Rf (C6F5/C6Cl2F3) exchange between [AuPf(AsPh3)] and trans‐[RhRf(CO)(AsPh3)2] does not occur by 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 to produce a [(Ph3As)Au−RhPfRf(CO)(AsPh3)2] intermediate, followed by isomerization and reductive elimination of [AuRf(AsPh3)]. Interesting differences were found between the LAu−Ar asymmetric oxidative insertion and the classical oxidative addition process of H2 to Vaska complexes.

Reversible Hydride Migration from C5Me5 to RhI Revealed by a Cooperative Bimetallic Approach

“…[33] However, the active participation of gold during hydride transfer cannot yet be ruled out. [34] The notion of reversibility is also in agreement with an FLP-type activation of EÀH bonds in the more congested system based on PCyp 2 Ar Xyl2 , where small amounts of monometallic Lewis base (1) and acid (2 c) may form in solution, behaving as an unusual thermally induced bimetallic FLP. [35] In fact, treatment of independently prepared [(PCyp 2 Ar Xyl2 )Au(NH 3 )]-(NTf 2 ) with 1 provide the same reaction outcome, that is, quantitative formation of equimolar amounts of compounds 5 and 6.…”

Análisis de los procesos de intercambio arilo/haluro en AuIII y revisión de los conceptos retrodonación e influencia trans en sistemas MIIICp*

“…25 The choice of this level of theory is based on the satisfactory results obtained on previous mechanistic studies with Au derivatives. 26 C and H atoms were described using the double-ζ basis set 6-31G(d,p), whereas the same basis set plus diffuse functions was employed to describe the more electronegative O, Cl and F atoms. Au and I were described using the effective core potential LANL2DZ 27 including f-polarization functions for Au (exponent: 1.050), 28 and d-polarization functions for I (exponent: 0.289).…”

“…25,26 23 Campeau, L. C.; Hazari, N. Cross-Coupling and Related Reactions: Connecting Past Success to the Development of New Reactions for the Future. Organometallics 2019, 38, 3.…”