KF/Al2O3 as a Green System for the Synthesis of Organochalcogen Compounds

This mini-review describes the interest in synthetic methodologies using KF/Al2O3 in various organic reactions focusing on the preparation of organochalcogen compounds. The use of this environmentally friendly reagent as an efficient and versatile heterogeneous base to promote the addition of chalcogen nucleophiles to alkynes and alpha,beta-unsaturated compounds has increased in the last decade. Besides addition reactions, substitution, cross-coupling, condensation, cyclization, multicomponent and oxidation reactions and others are among the plethora of methods to prepare organic compounds containing selenium, tellurium or sulfur. In a general way, the reactions using KF/Al2O3 as the base are cleaner and faster than those using homogeneous basic catalysis. The solid supported KF is suitable to reactions under solvent-free conditions accelerated by irradiation with microwaves and can be easily recycled and reused in successive reactions, making it an excellent choice for the green synthesis of organochalcogen compounds.