Click Synthesis of 1-Aryl-1,2,3-Triazole Derivatives Catalyzed by Recyclable Ligand Complex of Copper(Ⅱ) Supported on Superparamagnetic Fe_3O_4@SiO_2 Nanoparticles

摘要

We report a recyclable ligand complex of copper(II) supported on superparamagnetic Fe~(3)O~(4)@SiO~(2)nanoparticle catalytic system for efficiently synthesis of 1-aryl-1,2,3-triazole derivatives in excellent yields. The desired triazoles were obtained from the reaction of the corresponding aryl bronic acid derivatives, alkyne, NaN~(3), and 2.0 mol % of the catalyst in H~(2)O as the green solvent at 60 °C without the additional use of external reducing agent. The mechanism revealed that sodium azide, which is used as azidonating reagent in one-pot protocol reduces Cu(II) to click-active Cu(I). The suggested method offers several advantages such as excellent yields, short reaction time, operational simplicity, a cleaner reaction, and absence of any tedious workup or purification. In addition, the excellent catalytic performance in a water medium and the thermal stability, easy preparation and separation of the catalyst make it a good heterogeneous system and a useful alternative to other heterogeneous catalysts. Also, the aforementioned catalyst can be easily recovered by an external magnetic field and reused for subsequent reactions at least eight times without noticeable deterioration in catalytic activity.