Intimate relationship between C-I reductive elimination, aryl scrambling and isomerization processes in Au(III)...

Area of Science:

• Organometallic Chemistry
• Fluorinated Compounds
• Gold Complexes

Background:

• Gold(III) complexes are studied for various applications.
• Understanding ligand scrambling and reductive elimination is crucial for reaction control.

Purpose of the Study:

• To investigate the reaction pathways of trans-[AuRf2I2]- upon heating.
• To elucidate the factors controlling C-C versus C-I coupling in gold(III) systems.

Main Methods:

• 19F NMR spectroscopy for reaction monitoring.
• Kinetic modeling to describe system evolution.
• Density Functional Theory (DFT) calculations for mechanistic insights.

Main Results:

• Heating trans-[AuRf2I2]- results in isomerization and Rf/I scrambling, forming cis-[AuRf2I2]-, [AuRf3I]-, and [AuRfI3]-.
• Reductive elimination of C-I from [AuRfI3]- is kinetically favored over C-C coupling.
• A kinetic model involving I- dissociation accurately describes the experimental data.

Conclusions:

• The facile C-I reductive elimination pathway, driven by the weak Au-I bond, hinders desired C-C coupling.
• Reaction conditions should be optimized to avoid C-I coupling when C-C coupling is the target.