Photocatalysis Meets Copper Catalysis: A New Opportunity for Asymmetric Multicomponent Radical Cross-Coupling...

Area of Science:

• Organic Chemistry
• Catalysis
• Photochemistry

Background:

• Radical-mediated cross-coupling reactions offer molecular diversity but face challenges in selectivity and substrate scope.
• Visible-light photoredox catalysis and copper complexes are effective in generating and reacting with radicals.
• Synergy between chiral copper catalysts and photoredox catalysts presents an opportunity for enantioselective radical reactions.

Purpose of the Study:

• To develop innovative enantioselective multicomponent radical cross-coupling reactions.
• To explore the synergistic application of dual photoredox/copper catalysis and bifunctional copper catalysis under visible light.
• To expand the scope of radical cross-coupling reactions for accessing diverse chiral molecules.

Main Methods:

• Photoinduced copper-catalyzed chiral C-C and C-O bond formation via radical addition/nucleophilic trap sequence.
• Asymmetric carbocyanation and carboarylation of various unsaturated substrates.
• Esterification reactions using carboxylic acids as nucleophilic oxygen sources.
• Dual photoredox/copper catalysis for enantioselective three-component radical transformations via alkene activation.
• Radical cyanofunctionalization reactions (hydrocyanation, deuteriocyanation, cyanocarboxylation) using H2O, D2O, and CO2.

Main Results:

• Visible light effectively modulates radical generation for chemo- and stereoselectivity.
• Successful asymmetric carbocyanation and carboarylation of vinylarenes, 1,3-enynes, and 1,3-dienes.
• Development of esterification reactions for benzylic, allylic, and propargylic radicals.
• Enantioselective three-component radical cyanofunctionalization reactions yielding chiral nitriles with high enantiomeric excess.

Conclusions:

• The synergistic integration of photocatalysis and asymmetric copper catalysis offers immense potential for synthetic methodologies.
• Photocatalysis plays a crucial role in facilitating enantioselective multicomponent radical cross-couplings.
• These developed methodologies provide practical access to diversely functionalized chiral molecules.