Direct Decarboxylative Borylation of Aliphatic Carboxylic Acids via Molecular Photoelectrocatalysis

Direct decarboxylative borylation of aliphatic carboxylic acids offers an attractive route to alkyl organoboron compounds from abundant and readily available feedstocks, yet a general and practical method for this transformation remains underdeveloped. Herein, we report a molecular photoelectrocatalytic strategy for the direct decarboxylative borylation of unactivated aliphatic carboxylic acids. The method relies on iron-catalyzed, photoinduced ligand-to-metal charge transfer (LMCT) activation of aliphatic carboxylic acids to generate alkyl radicals under mild conditions, thereby avoiding the preactivation of carboxylic acids as redox-active derivatives. By merging photochemical and electrochemical activation of the iron catalyst, this protocol enables oxidative decarboxylative C–B bond formation without the use of stoichiometric chemical oxidants. The method exhibits good functional-group tolerance, and its practicality is demonstrated by gram-scale synthesis. This work provides a concise platform for the direct conversion of unactivated aliphatic carboxylic acids into valuable alkyl boronates.