A “one-pot” synthesis of adipic acid from cyclohexene under mild conditions with new bifunctional Ti-AlSBA mesostructured catalysts

Abstract

Aluminium incorporation into a mesostructured silica, SBA15, either by direct synthesis or by post-synthesis, followed by titanium grafting, leads to new bifunctional Ti-AlSBA15 catalysts. Materials obtained by co-hydrolysis of aluminium and silicon sources (Ti(16)Al(DS)SBA) are very active in the “one-pot” synthesis of adipic acid. Yields up to 80% are reached under mild conditions (353 K, 24 h) using cyclohexene and tert-butyl hydroperoxide. Cyclohexene oxide and trans-1,2-cyclohexandiol are potential intermediates. Both catalysts precursors can be recycled without any loss of activity. Leaching of active titanium species is negligible as checked by elemental analysis and catalysis tests with the recovered solutions.