Ring Expansion of Benzofurans by Single-Silicon Insertion

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Organosilicon Chemistry

Background:

• Organosilicon compounds are crucial in medicinal chemistry.
• Scaffold-hopping by inserting silicon into heterocycles is an underdeveloped strategy.
• Expanding drug-like chemical spaces is a key goal in drug discovery.

Purpose of the Study:

• To report a novel Ni-catalyzed reaction for silicon atom insertion into benzofurans.
• To transform readily available benzofurans into high-value oxasilacycles.
• To establish a versatile platform for skeletal editing of benzofurans.

Main Methods:

• Nickel-catalyzed C-H bond silylation of benzofurans.
• Induction of 1,2-oxygen migration.
• Utilizing benzofurans as starting materials.

Main Results:

• Successful synthesis of oxasilacycles from benzofurans.
• Demonstration of silicon atom insertion via C-H silylation and oxygen migration.
• Oxasilacycles serve as versatile synthons for diverse compound generation.

Conclusions:

• The developed reaction provides access to various cyclic skeletons, including oxaborins, coumarins, benzooxepines, and polycyclic oxasilaalkanes.
• This method significantly diversifies the initial benzofuran core.
• Establishes a versatile platform for skeletal editing, broadening the synthetic toolbox for medicinal chemistry.