Biasing Mechanistically-Distinct Reaction Pathways by Mechanochemistry

Abstract

Due to the solvent-free nature of mechanochemical approach, it offers an opportunity to drive reactions with different selectivity from those under conventional solution-based conditions. Nevertheless, literature examples of pathway switching remain scarce. Herein, we report an unusual example where ball-milling offers three distinct pathways leading to three different products. By simply adjusting the amount of liquid additive, arene C-H functionalization can be biased between bromination and oxidation via either radical (Br •) or ionic (Br +) intermediate, respectively.