For reasons of economy and pollution, solvent-free methods are of great interest in order to

modernize classical procedures making them more clean, safe and easy to perform. Reactions

on solid mineral supports, reactions without any solvent/support or catalyst, and solid-liquid

phasetransfercatalysiscanbethusemployedwithnoticeableincreasesinreactivityand

selectivity. A comprehensive review of these techniques is presented here. These methodolo-

gies can moreover be improved to take advantage of microwave activation as a beneficial alter-

native to conventional heating under safe and efficient conditions with large enhancements in

yields and savings in time.