Ball Milling in Organic Transformations

In organic synthesis, mechanochemical approaches have received increased attention because of their broad applications in green methodologies. By utilization of mechanical forces on the various reactants, there is a certain increase of their surface area and also areas of contact, which usually make reaction pathways more available through a greater number of effective collisions. Mechanical energy can be produced and transferred through ball mills, one of the highest necessary devices for green organic solid-state reactions. In the last few decades, various challenging organic transformations have been published using ball milling in different fields of organic synthesis. Ball milling has received tremendous attention in numerous organic synthesis since it allows for reactions to occur at ambient temperature in the absence of any solvent under mild conditions which are compatible for a green process. The carbon-carbon and carbon–heteroatom bond formation reactions and also synthesis of heterocyclic compounds are of ample importance in both academia and pharmaceutical industry. This review will highlight the recent developments of amidation reactions, asymmetric synthesis, various heterocyclic compounds synthesis, crosscoupling reactions, C–H bond activation for C–C and carbon–heteroatom bond formation reactions under the ballmilling conditions.