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 the classical 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 purification step other than an aqueous washing
was required.
microwave irradiation - Petasis borono-Mannich reaction - green chemistry - solvent-free
