Ring expansion of indene by photoredox-enabled functionalized carbon-atom insertion

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Photochemistry

Background:

• Skeletal editing is crucial for late-stage molecular scaffold modification.
• Functionalized carbon atom insertion into aromatic rings remains a significant synthetic challenge.
• Existing methods for carbon atom insertion are limited in scope and functional group tolerance.

Purpose of the Study:

• To develop a novel photoredox-enabled method for functionalized carbon atom insertion into indene.
• To expand the scope of skeletal editing reactions for complex molecule synthesis.
• To demonstrate the utility of the developed methodology in pharmaceutical chemistry.

Main Methods:

• Utilized a photoredox catalyst system.
• Employed a radical carbyne precursor for carbon atom insertion.
• Applied the reaction to indene substrates to form naphthalene derivatives.

Main Results:

• Successfully achieved functionalized carbon atom insertion into indene.
• Generated a library of 2-substituted naphthalenes with diverse functional groups (e.g., CF3, ester, nitrile, ketone).
• Demonstrated the method's applicability to pharmaceutically relevant molecules.

Conclusions:

• The developed photoredox-enabled reaction provides a versatile approach for skeletal editing.
• This method significantly broadens the range of functional groups that can be inserted into aromatic systems.
• The strategy holds promise for the efficient synthesis of complex pharmaceutical compounds.