Intramolecular Benzyne-Phenolate [4+2] Cycloadditions

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Intramolecular cycloaddition reactions are crucial for constructing complex molecular architectures.
• Benzyne chemistry offers a versatile platform for carbon-carbon bond formation.

Purpose of the Study:

• To report a novel intramolecular benzyne-phenolate [4+2] cycloaddition reaction.
• To synthesize benzobarrelene derivatives using readily accessible precursors.

Main Methods:

• Synthesis of benzyne precursors bearing vicinal halogen-sulfonate functionalities.
• Treatment of precursors with organometallic reagents (Ph3MgLi or nBuLi) to induce halogen-metal exchange.
• Facilitation of intramolecular [4+2] cycloaddition between the generated benzyne and the tethered phenolate.

Main Results:

• Efficient formation of benzobarrelenes through the intramolecular cycloaddition.
• Demonstration of the reaction's utility with various tether groups.
• Successful generation of reactive benzyne intermediates under mild conditions.

Conclusions:

• The reported method provides a facile route to benzobarrelenes.
• This intramolecular cycloaddition expands the synthetic utility of benzyne chemistry.
• The strategy is amenable to the synthesis of diverse polycyclic compounds.