磁性磺酸催化生物质基呋喃“一锅多步”合成N-取代吡咯

Magnetic Sulfonic Acid-catalyzed“Multi-steps One-pot”Synthesis of N-substituted Pyrroles from Bio-based Furan

生物质衍生物2,5-二甲基呋喃可与一系列芳胺化合物经过酸催化开环、Paal-Knorr缩合等反应“一锅法”合成2,5-二甲基-N-芳基吡咯。在所设计优筛的酸催化材料中,一种新型磁性碳基磺酸固体催化剂(WK-8)表现出较优异的催化性能(可达约90%的产率),并且易于通过外加磁场分离回收。同时,呋喃开环被证实为上述“一锅多步”转化过程的决速步骤,但是水的加入可显著提升上述基元反应。此外,系列表征手段证实该磁性磺酸催化剂在含水反应氛围中具有良好的稳定性。

In this study,“one-pot”catalytic synthesis of various 2,5-dimethy-N-arylpyrroles was achieved by cascade ring-opening and Paal-Knorr condensation of biomass-derived 2,5-dimethylfuran with aromatic amines.Among the designed and optimized catalytic materials,a novel magnetic-SO 3H catalyst(WK-8)showed superior catalytic performance(up to ca.90%yield)in the cascade conversion processes,which was also found to be recyclable using an external magnet.Meanwhile,the furan ring-opening reaction is demonstrated to be the rate-determining step of the overall reaction,while the addition of water could remarkably accelerate the elemental reaction.In addition,a series of characterization methods confirmed that the magnetic-SO 3H catalyst(WK-8)was highly stable in the moisture reaction atmosphere.