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采用浸渍法制备了多壁碳纳米管(MWCNT)负载的Cu2O和CuI催化剂,并运用粉末X射线衍射、红外光谱、扫描电镜-能量散射谱、透射电镜和NH3程序升温脱附等技术对催化剂进行了表征。结果表明,催化剂中沉积的Cu2O和CuI分别以立方相和γ相存在于MWCNT上,且表现出由弱到强的拉电子(Lewis酸)性能。将催化剂用于催化芳醛与2-氨基吡啶氧化酰胺化反应合成N-(吡啶-2-基)苯酰胺类化合物,产物选择性为100%,收率为50%–95%。 CuI/MWCNT催化剂上产物分离收率性能好于Cu2O/MWCNT,但后者的循环使用性能更好。与共价的CuI相比,离子化的Cu2O与极性的酸活化的MWCNT间具有更适宜的相互作用,这种不同的相互作用可显著影响2-氨基吡啶的氨基对芳醛羰基的亲核进攻速率。

Cu2O and CuI were supported on multiwalled carbon nanotubes (MWCNTs) using a wet impregna‐tion method, and the resulting materials were fully characterized by powder X‐ray diffraction, Fou‐rier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X‐ray spectroscopy, transmission electron microscopy, and temperature‐programmed desorption with ammonia analysis. The results of these experiments revealed that Cu2O and CuI were deposited on the MWCNTs in the cubic and γ phases, respectively. These results also showed that the Cu‐containing MWCNTs exhibited weak to strong electron‐accepting (Lewis acidic) properties. The catalytic activities of these materials were studied for the synthesis of biologically significant N‐(pyridin‐2‐yl)benzamides via the oxidative amidation of aryl aldehydes with 2‐aminopyridines. The yields of the products were in the range 50%–95% with 100% selectivity. Notably, the CuI/MWCNT catalyst was much more effective than the Cu2O/MWCNT catalyst with respect to the isolated yield of the product, although the latter of these two catalysts exhibited much better recy‐clability. A preferential interaction was observed between the polar nature of the acid‐activated MWCNTs and the ionic Cu2O compared with covalent CuI. The differences in these interactions had a significant impact on the rate of the nucleophilic attack of the amino group of 2‐aminopyridine substrate on the carbonyl group of the aryl aldehyde.