Flash Communication: Challenging Computational Description of Gold(I)/Gold(III) Catalytic Cycles.

Area of Science:

• Organometallic chemistry
• Catalysis
• Computational chemistry

Background:

• Gold(I) complexes are increasingly utilized in catalysis.
• Chelating ligands are typically employed in gold-catalyzed cross-coupling reactions.
• Pioneering work by Kochi highlighted the potential of gold complexes with simple ligands.

Purpose of the Study:

• To investigate the mechanism of gold(I)-catalyzed cross-coupling reactions without chelating ligands.
• To computationally characterize the catalytic cycle using density functional theory (DFT).
• To explore the role of simple alkyl phosphine ligands in gold catalysis.

Main Methods:

• Experimental investigation of the reaction between cinnamyl bromide and PhSnMe3.
• Computational modeling using density functional theory (DFT).
• Analysis of a proposed gold(I)/gold(III) catalytic cycle.

Main Results:

• The reaction between cinnamyl bromide and PhSnMe3 was experimentally confirmed with a [Me3PAuCl] complex.
• Computational DFT calculations revealed significant challenges in characterizing the catalytic mechanism.
• A wide range of energy values were obtained using different DFT functionals, indicating complexity.

Conclusions:

• Gold(I) complexes with simple phosphine ligands can catalyze cross-coupling reactions.
• Computational modeling of the gold(I)/gold(III) catalytic cycle presents unexpected complexities.
• Further methodological development in DFT is needed for accurate mechanistic studies in such systems.