الفهرس | Only 14 pages are availabe for public view |
Abstract The synthesis of triazole compounds through click reaction had gained great attentions from the scientists from different disciplines such as chemistry, biology and others. Previously, the Huisgen [3+2] cycloaddition reaction between azides and terminal acetylene was affording a mixture of two isomers of triazole derivatives were obtained (1,4-disubtituted and 1,5-disubstituted triazoles). Hence, the scientists attempted to develop various catalysts for preparation of only one selective isomer. Cu salts and CuO NPs had wide applications in the above-mentioned reactions that gave selectively 1,4-disubstituted triazole derivatives. Therefore, in this study, we aimed to make modification on CuO NPs by the synthesis of CuO/NiO NCs and examining these two catalysts in click reaction by reacting phenyl acetylene with organic azides to produces three derivatives of 1,4-disubstituted 1,2,3-1H-triazole in combination with microwave technique. These two nanocatalysts were prepared by precipitation method. They were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), UV- Vis absorption analysis and identification of functional groups using infra-red spectroscopy (FTIR). These analyses revealed that the two nanocatalysts were obtained in pure form without impurities. Three triazole derivatives were obtained by employing CuO NPs and CuO/NiO NCs. These reactions were assisted by microwave irradiation that helped in reduction of the reaction time and obtaining high yields of the products. These reactions was considered as region-specific reactions, since the obtained triazole compounds were isolated as 1,4-disubstituted triazole derivatives and there were no detection for any regio- isomers. These results were in accordance with the click chemistry concept that was illustrated by Sharpless and his co-workers. Another privilege in this protocol was the formation of the target compounds in short reaction time within 7-9 min and high yield were afforded (85-88%). The comparison between the two as-prepared catalysts was described to show that CuO/NiO NCs was highly efficient catalyst more than CuO NPs in click reaction under microwave condition. The recyclability of CuO/NiO catalyst was performed that showed the stability of the catalyst under the investigated conditions. |