Highly Efficient Polyacrylonitrile Fiber Catalysts Functionalized by Aminopyridines for the Synthesis of 3-Substituted 2-Aminothiophenes in Water

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• 作者：Pengyu Li ; Jianguo Du ; Yujia Xie ; Minli Tao ; Wen-Qin Zhang
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2016
• 出版时间：March 7, 2016
• 年：2016
• 卷：4
• 期：3
• 页码：1139-1147
• 全文大小：463K
• ISSN：2168-0485

文摘

Four aminopyridine (AP) functionalized polyacrylonitrile fibers (PAN_APFs) were developed. UV–vis, FTIR, EA, and SEM were used to demonstrate the successful preparation of the fiber catalysts. Among the prepared catalysts, the PAN_p-AP-3F (with a C₃ chain linker) and PAN_p-AP-6F (with a C₆ chain linker) exhibited the best catalytic activity to efficiently catalyze the Gewald reaction of ethyl cyanoacetate and 2,5-dihydroxy-1,4-dithiane in water with yields up to 92% under a low catalyst dosage of 1 mol %. The influences of the position and length of the linker, i.e., the carbon chain between the fiber backbone and the aminopyridine moiety, on the catalytic activities were investigated in detail. In addition, the selected catalyst PAN_p-AP-3F was applied to the Gewald reaction of a series of active nitriles and 2,5-dihydroxy-1,4-dithiane and reused without further treatments. A possible mechanism and a microenvironment promoting process were conceived to explain the excellent catalytic properties of this catalytic system. Furthermore, the PAN_p-AP-3F performed well in a scaled-up experiment indicating its potential application in industry.