Piezoelectric-Driven Mechanochemical Halogenation: A Transformative Pathway for Sustainable Sandmeyer Reactions via Ball Milling.

Abstract

The Sandmeyer reaction is a key method for synthesizing aryl halides but often requires complex procedures and large solvent volumes. This study introduces a mechanoredox system using ball milling to activate piezoelectric BaTiO3, enabling solvent-minimized, metal-catalyst-free halogenation of aryl diazonium salts under air. The method features a broad substrate scope, scalability, and recyclable piezoelectric materials without significant activity loss. This sustainable approach overcomes the limitations of traditional Sandmeyer reactions, providing an efficient and practical alternative for aryl halide synthesis.