Understanding the Organometallic Step: SO₂ Insertion into Bi(III)-C(Ph) Bond

Area of Science:

• Organometallic Chemistry
• Main-Group Catalysis

Background:

• Transition metal catalysts are widely used in chemical transformations.
• Heavier main-group elements offer a promising alternative, mimicking transition metal behavior.
• Bismuth-catalyzed synthesis of aryl sulfonyl fluorides has recently been reported.

Purpose of the Study:

• To elucidate the mechanism of a bismuth-catalyzed reaction.
• To understand the role of the hypervalent bismuth center in catalysis.
• To explore the factors enabling main-group elements to mimic transition metals.

Main Methods:

• Theoretical studies were employed to investigate the reaction mechanism.
• Analysis focused on the coordination and migration steps involving sulfur dioxide and the phenyl group.

Main Results:

• Bismuth(III) facilitates sulfur dioxide coordination through hypervalent coordination.
• The polar bismuth-phenyl bond enables feasible phenyl group migration.
• The phenyl group's pi electron pair stabilizes the transition state during sulfur dioxide insertion.

Conclusions:

• Hypervalent coordination and polar bonds are key features enabling heavier main-group elements in catalysis.
• Bismuth catalysis demonstrates flexibility in ligand association and dissociation, akin to transition metals.
• This study provides fundamental insights into the mechanisms of heavier main-group element catalysis.