Mechanophotocatalysis

This proof-of-concept study establishes the viability and generality of mechanophotocatalysis, merging mechanochemistry and photocatalysis to enable solvent-minimized photocatalytic reactions. We demonstrate the transmutation of four archetypal solution-state photocatalysis reactions to a solvent-minimized environment driven by the combined actions of milling, light, and photocatalysts. The chlorosulfonylation of alkenes and the pinacol coupling of aldehydes and ketones were conducted under solvent-free conditions with competitive or superior efficiencies to their solution-state analogues. Furthermore, decarboxylative alkylations are shown to function efficiently under solvent-minimized conditions, while the photoinduced energy transfer promoted [2+2] cycloaddition of chalcone experiences a significant initial rate enhancement over its solution-state variant. This work serves as a platform for future discoveries in an underexplored field, validating that solvent-minimized photocatalysis is generalisable and competitive with solution-state photocatalysis.