Mechanical energy as a programmable redox input enables boronic acid activation for direct C–H functionalization of heteroarenes

The development of sustainable strategies for radical-mediated C–H functionalization is essential for greener synthesis. Herein, we demonstrate that mechanical energy can serve as a programmable redox stimulus through the piezoelectric properties of BaTiO 3 , enabling mechanoredox C–H arylation and alkylation of heteroarenes under vibratory shaker mill conditions. Mechanical agitation transiently polarizes BaTiO 3 , promoting persulfate activation to generate sulfate radicals that convert aryl and alkyl boronic acids into carbon-centered radicals. The transition-metal-free, solvent-minimized protocol affords diverse functionalized heteroarenes with excellent functional group tolerance and enables late-stage diversification of active pharmaceutical ingredients, ligand scaffolds, and materials-relevant intermediates. The method is scalable, while BaTiO 3 can be recovered and reused over multiple cycles. Mechanistic studies support a sulfate-radical-mediated pathway analogous to Minisci chemistry. Overall, this work establishes recyclable piezoelectric materials and mechanical energy as a sustainable platform for radical C–H functionalization.