木质素磺酸铁催化合成N-取代吡咯

Synthesis of N-substituted pyrroles using ferric lignosulfonate as catalyst

以造纸废料木质素磺酸钠为原料制备了木质素磺酸铁。以木质素磺酸铁为催化剂,催化2,5-己二酮与伯胺发生Paal-Knorr反应,生成了高产率的N-取代吡咯。该反应是典型的亲核反应,伯胺亲核性越强,反应速率越快,N-取代吡咯产率越高。反应中木质素磺酸铁电离出的Fe^3+是Lewis酸,起催化作用。木质素磺酸铁是一种生物质基固体催化剂,价廉易得、环境友好、操作简便、易于和产物分离、可回收循环使用。

Ferric lignosulfonate was prepared using paper-making waste sodium lignosulfonate as raw material.The Paal-Knorr reaction of 2,5-hexanedione with primary amine was achieved using ferric lignosulfonate as a catalyst to produce the N -substituted pyrroles in high yields.The nucleophilicity of primary amine had impact on this nucleophilic reaction.The strong nucleophilic primary amines afforded higher product yields in shorter reaction time.The Fe 3+ ionized from ferric lignosulfonate was truly catalytic species in this transformation.The results exhibited that this biomass-derived solid Lewis acid catalyst had the merit of cheapness and easy availability,simple operation,easy separation from the products,recycling of catalyst,moreover it was benign to environment.