Copper-mediated anomeric O-arylation with organoboron reagents

Area of Science:

• Organic Chemistry
• Carbohydrate Chemistry
• Catalysis

Background:

• O-aryl glycosides are important structural motifs in medicinal chemistry and materials science.
• Efficient synthesis of O-aryl glycosides, particularly via Csp2-O bond formation, remains a synthetic challenge.

Purpose of the Study:

• To develop a novel copper-mediated coupling method for the synthesis of O-aryl glycosides.
• To explore the anomeric O-arylation of diverse protected pyranose and furanose derivatives.

Main Methods:

• Copper-catalyzed coupling reaction between arylboroxines and glycosyl hemiacetals.
• Utilized protected pyranose and furanose derivatives as substrates.
• Investigated the scope and limitations of the reaction with functionalized arylboroxine partners.

Main Results:

• Successful synthesis of O-aryl glycosides through Csp2-O bond formation.
• Demonstrated the anomeric O-arylation of protected pyranose and furanose derivatives.
• Observed selective formation of the α-anomer from mannopyranose and mannofuranose substrates, while mixtures of anomers were formed from other sugar derivatives.

Conclusions:

• The developed copper-mediated coupling provides a versatile route to O-aryl glycosides.
• The method is tolerant of various functional groups on arylboroxine partners.
• Stereoselective synthesis of α-O-aryl glycosides is achievable with specific mannose-derived substrates.