Résumé
A new solvent-free microwave-assisted procedure for the Petasis multicomponent reaction was developed. This method is the first application of the borono-Mannich reaction in solvent-free conditions and proved its applicability to various boronic acids and secondary amines. Results are very good in term of yields, with shorter reaction time than with classic methods. Because of the efficiency of the method, full conversion of the starting materials towards the expected product was achieved, starting from stoichiometric quantities of reactants, avoiding the usual solvent consuming column chromatography on silica gel. No other purification step than an aqueous washing was required.