Hydrogen-Bonding-Driven Site-Selective Activation of α-C(sp)─H in Alcohols: A Straightforward Dual-Catalysis Strategy for Efficient Acceptorless Dehydrogenation.

The transformation of alcohols into corresponding carbonyl derivatives is of paramount importance for the construction of complex molecules. Current strategies for catalytic acceptorless dehydrogenation of alcohols were predominantly confined to reactive alcohols, such as benzyl or allyl alcohols, due to the relatively high α-C(sp)─H bond dissociation energy of the conventional unreactive alcohols. Notably, weak bond catalysis, particularly hydrogen bonding, can selectively activate C─H bonds by modulating the distribution of electron density. Herein, we have developed a dual-catalysis platform that enabled highly efficient oxidation of alcohols promoted by a multifunctional catalyst. This strategy achieves selective activation of the hydroxyl α-C(sp)─H bond via hydrogen bonding interactions and polarity matching, which is compatible with both primary and secondary alcohols, demonstrating potential applications in pharmaceutical synthesis. Moreover, DFT studies provide compelling evidence that hydrogen-bond interactions between 3-quinuclidinone and alcohols play a pivotal role in enhancing the catalytic efficiency.