A new synthetic strategy was devised leading to the formation of complexes, such as [Au(IPr)(CH₂COCH₃)]. The approach capitalizes on the formation of a decomposition product observed in the course of the synthesis of [Au(IPr)(Cl)]. A library of gold acetonyl complexes containing the most common N-heterocyclic carbene (NHC) ligands has been synthesized. These acetonyl complexes are good synthons for the preparation of numerous organogold complexes. Moreover, they have proven to be precatalysts in common gold(I)-catalyzed reactions.

The synthesis and characterization of three novel trifluoromethylamido-containing “boomerang” precatalysts bearing various N-heterocyclic carbene (NHC) ligands are reported. Comparative kinetic and stability studies show the significant effect of the NHC on the catalyst reaction profile. An investigation of the reaction scope for diverse metathesis transformations has allowed us to establish the influence of the NHC on catalyst activity, especially as a function of substrate steric bulk. The excellent stability of one of the novel precatalysts is disclosed, and allowed for its recovery at the end of catalytic reactions. Large-scale ring-closing metathesis, enyne-metathesis and cross-metathesis experiments have revealed the recoverability of the catalyst. ICP-MS analyses of the synthesized products reveal Ru contamination levels of less than 2.5 ppm.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Complexes of palladium bearing NHC ligands (NHC=N-heterocyclic carbene) were synthesized and fully characterized. The [Pd(NHC)(allyl)Cl] series was obtained by simple cleavage of [Pd(allyl)Cl]₂ by using either the isolated free NHC or the in situ generated NHC. The NHC ligand sterics were varied by introduction of groups attached to the C4–C5 carbon atoms of the NHC backbone. Results of the X-ray diffraction study permitted determination of the NHC steric parameters within this series. It was observed that the NHC backbone induces variations in its percent buried volume (%V_bur) as a function of the N-substituents.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)