Silent Partners in the Mill: Unveiling the Role of Additives in Mechanochemical Synthesis

Abstract

Mechanochemistry has attracted significant attention as a sustainable and efficient alternative to solution-based synthesis, offering the advantage of solvent-free conditions or the use of only minor amounts of solvent. Many established mechanochemical transformations rely on the use of additives—a strategy broadly referred to as additive-assisted grinding. The most employed additives are liquids (liquid-assisted grinding (LAG)), ionic solids, and non-ionic additives. Additionally, ionic liquids (ionic liquid-assisted grinding (IL-AG)), piezoelectric, or mechanoluminescent materials can be used. This review provides an overview of additive-assisted organic synthetic transformations under mechanochemical conditions, highlighting the roles, advantages, and limitations of additives, as well as emerging trends from recent literature.