In recent years, solvent-less mechanochemical organic reactions using ball milling have come to the forefront of organic synthesis as cleaner and sustainable synthetic alternatives to conventional solution-based approaches. Apart from the environmental benefits, mechanochemical approaches potentially enable access to novel chemical space that has reactivities and selectivities different from those of conventional solution-based reactions. In this context, we have focused on the development of new solid-state organic transformations using mechanochemistry. We recently succeeded in developing broadly applicable solid-state palladium-catalyzed cross-coupling reactions under mechanochemical conditions. The key finding of these studies is that alkene additives can cat as dispersants for the palladium-based catalyst and also as stabilizer for the active monomeric palladium (0) species, thus facilitating these challenging solid-state bond forming reactions. In addition, we have discovered a conceptually new redox system, in which electrons are transferred from distorted piezoelectric materials in the solid-state to trigger organic transformations. This 'mechanoredox' system represents a unique solid-state approach that is complementary to photoredox reactions in solution.