Abstract:

Walnut shell powders(WSPs), which were grinded from walnut shell, was used as supporter for the preparation of WSPs-supported copper catalyst(WSPs-Cu) by adsorption method. The heterogeneous catalyst WSPs-Cu was characterized by FT-IR, thermogravimetric analysis(TGA), X-ray diffraction analysis(XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy(SEM/EDS). The results showed that the WSPs-Cu catalyst was successfully prepared by this method. Copper were well distributed on the surface of WSPs. The copper content of the catalyst was 3.386% with good thermal stability within 100-200 ℃. The WSPs-Cu catalyst was used to prepare five ynones from benzoyl chloride derivatives and phenylacetylene via copper-catalyzed coupling reaction. The results revealed that ynones were synthesized under microwave irradiation and solvent-free conditions for 30 min at 40 ℃ by using triethylamine as acid-binding agent(61%-90%). The recyclability of WSPs-Cu was studied. It was found that the WSPs-Cu has high activity after using for five times and the yield was 79%. As the model reaction was amplified from trace to constant and the dosage of substrate was 80 mmol, the yield of ynone catalyzed by WSPs-Cu reached 82%.

Key words: walnut shell powders, ynones, heterogeneous catalyst, microwave