SYNTHESIS AND EVALUATION OF CATALYTIC ACTIVITY IN WATER AND MICROWAVE IRRADIATION OF A NEW SUPPORT BASED ON HNT TRIAZOLIUM SALTS

In the last years SILLP (supported ionic liquid-like phase)-based materials prepared by covalent attachment have been synthesized [1]. Recently, we have synthesized a palladium-based catalytic system using halloysite nanotubes modified with octylimidazolium moieties and we have tested it in the Suzuki cross-coupling reaction under traditional heating, microwave irradiation and a very small amount of Pd catalyst [2,3]. It is known that support based on triazole motif showed superior activity to the analogous imidazole molecules [4] so, we have focused our attention to develop a new SILLP system with triazolium moiety. Herein we report the synthesis of an original Pd-dicationic triazolium support based on halloysite nanotubes (HNT-triazo/Pd). The new HNT/Pd catalyst was used as catalyst in the Suzuki reaction under microwave irradiation. The best experimental conditions were obtained when the reactions were carried out for 10 minutes in water at 120 °C in presence of K2CO3 as base using 0.1 mol% of catalyst. Good recyclability was observed too.