Catalyst-Dependent Direct and Deoxygenative Coupling of Alcohols by Convergent Paired Electrolysis

Developing a general and mild approach to upgrade alcohols into high value products is a hot topic in synthetic chemistry because alcohol is one of the most abundant raw chemicals. Specifically, direct coupling and deoxygenative coupling of alcohols are the two main approaches for the functionalization of alcohols to afford structurally diverse products, and it receives considerable attention. Despite significant advances in the field, there still remains a great challenge to develop a general approach accommodating both coupling reactions, as they commonly involve distinct pathways. Herein, we report an electrochemical approach for the direct coupling and deoxygenative coupling of alcohols with fluorenones. Under paired electrolysis, this catalyst-dependent protocol gives divergent access to diols and tertiary alcohols. Moreover, the synthetic utility of 9H-fluoren-9-ol products has been demonstrated in the synthesis of organic luminophores, phenanthrol, phenanthridine, and amino alcohol. The present approach exhibits some impressive features: (a) catalyst-dependent selectivity; (b) excellentfunctional-group tolerance (156 examples); (c) mild conditions; and (d) good scalability (similar to 20 gram scale). [GRAPHICS]

Automated summary

This study presents an electrochemical approach for the direct coupling and deoxygenative coupling of alcohols with fluorenones, providing a new pathway for synthesizing high value products. The method features excellent functional-group tolerance, mild reaction conditions, and good scalability.