DMAP-stabilized bis(silyl)silylenes as versatile synthons for organosilicon compounds.

Area of Science:

• Organosilicon Chemistry
• Main Group Chemistry
• Reaction Mechanisms

Background:

• Silylenes are reactive silicon intermediates.
• Stabilization of silylenes is crucial for studying their reactivity.
• DMAP (4-dimethylaminopyridine) can stabilize reactive species.

Purpose of the Study:

• To synthesize and characterize DMAP-stabilized silylenes.
• To investigate the thermal isomerization reactions of these silylenes.
• To explore the catalytic potential of silylenes in H2 activation.
• To isolate and characterize novel silicon-centered radicals.

Main Methods:

• Reductive debromination of dibromosilanes in the presence of DMAP.
• Thermal treatment of silylene complexes to induce isomerization.
• Spectroscopic characterization of intermediates and products.
• Isolation and structural determination of a potassium-substituted silicon radical.

Main Results:

• Synthesis of DMAP-stabilized silylenes (1a-c) via reductive debromination.
• Observation of distinct thermal isomerization pathways: C-H activation, dearomative ring expansion, and silyl migration.
• Dissociation of silylene complexes at elevated temperatures to generate free silylenes.
• Demonstration of single-site H2 activation by the *in situ* generated free silylenes.
• Isolation of a potassium-substituted silicon-centered radical (2) from overreduction.

Conclusions:

• DMAP provides effective stabilization for silylenes, enabling the study of their unique thermal reactivity.
• Silylenes exhibit diverse reaction pathways, including C-H activation and ring expansion.
• Free silylenes generated *in situ* show potential for catalytic applications like H2 activation.
• Novel silicon-centered radicals can be accessed through controlled reduction processes.