Primary amine-functionalized mesoporous phenolic resin as an effective and stable solid base catalyst for Knoevenagel reactions in water
Kaixuan Wang, Huating Jiang, Min Tong, Yao Xiao, Hexing Li, Fang Zhang
Abstract
A primary amine functionalized ordered mesoporous phenolic resin (NH2-MPR) was obtained by an evaporation-induced self-assembly method. The as-prepared NH2-MPR material possessed large surface area and ordered two-dimensional hexagonal mesoporous structure. Also, the amine groups were well-dispersed in the mesoporous channels. It can act as an efficient solid base to promote Knoevenagel condensation of various aldehydes with ethyl cyanoacetate in water with high conversion and selectivity. This excellent performance was attributed ordered mesopores and hydrophobic pore surface, which resulted in the decreased the interference of water solvent and the increased active sites accessibility. Noted that it was comparable with homogenous base catalysts in the water-medium Knoevenagel condensation reaction, and it can be reused for at least five times without significant reduction in the catalytic efficiency.