Couple-close: Unified approach to semisaturated cyclic scaffolds

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Semisaturated cyclic scaffolds are valuable due to their unique Csp2 and Csp3 hybridized components.
• Current methods for synthesizing these scaffolds are limited, often requiring lengthy de novo syntheses or arene saturation.

Purpose of the Study:

• To introduce a unified and modular couple-close strategy for constructing semisaturated cyclic scaffolds.
• To overcome limitations of existing synthetic methods for these important molecular structures.

Main Methods:

• Installation of bifunctional linkers onto aromatic rings via diverse bond-forming reactions.
• A cobalt-catalyzed dehydrogenative radical cyclization for forming bicyclic adducts.
• Mild reaction conditions enabling a broad substrate scope, including electronically unbiased arenes.

Main Results:

• Successful synthesis of semisaturated bicyclic adducts using the couple-close strategy.
• Demonstration of a mechanistically distinct cobalt-catalyzed cyclization.
• High efficiency and broad substrate scope achieved under mild conditions.

Conclusions:

• The couple-close strategy offers a powerful and modular approach to semisaturated scaffold synthesis.
• This method provides a significant advancement over existing techniques, simplifying complex cyclic molecule construction.
• The cobalt-catalyzed cyclization is a key innovation, enabling efficient synthesis on diverse aromatic substrates.