Efficient using of green heterogeneous catalysts from renewable natural sources through chemical modification for the cycloaddition of terminal epoxides with CO₂ is attractive but still challenging. Luffa sponge is a cheap, biodegradable, abundant and renewable source with netting-like three-dimensional porous structure. Herein, we report a simple and facile approach to the preparation of a series of novel luffa sponge-supported dendritic imidazolium ILs heterogeneous catalysts LS-DIL-(G1-G3) with high ionic density from natural luffa sponge fibers. LS-DIL-(G1-G3) were properly characterized by FT-IR spectroscopy, TGA, elemental analysis, and SEM. Among them, LS-DIL-G3 was found to exhibit the highest catalytic activity for the synthesis of cyclic carbonates under metal-free and solvent-free conditions. It was clearly observed that there was a positive dendritic effect on the yields of cyclic carbonates. Furthermore, a wide range of terminal epoxides was converted smoothly to the corresponding cyclic carbonates with high yields (84–99 %). LS-DIL-G3 could be reused for up to six consecutive runs without any obvious decline in catalytic activity. Importantly, the desired cyclic carbonates could be prepared on a multigram scale by using LS-DIL-G3 as a green heterogeneous catalyst.

通过化学改性有效地利用可再生天然来源的绿色多相催化剂，将末端环氧化物与CO ₂进行环加成反应很有魅力，但仍然充满挑战。Luffa海绵是一种廉价，可生物降解，丰富且可再生的资源，具有网状三维多孔结构。在这里，我们报告了一种简单而简便的方法来从天然丝瓜海绵纤维制备具有高离子密度的一系列新型丝瓜海绵负载的树枝状咪唑类ILs非均相催化剂LS-DIL-（G1-G3）。LS-DIL-（G1-G3）已通过FT-IR光谱，TGA，元素分析和SEM进行了适当表征。其中，发现LS-DIL-G3在无金属和无溶剂条件下显示出最高的催化活性，用于合成环状碳酸酯。清楚地观察到，对环状碳酸酯的产率具有积极的树枝状作用。此外，各种各样的末端环氧化物可以平稳地转化为相应的环状碳酸酯，收率很高（84–99％）。LS-DIL-G3最多可重复使用六次，而催化活性没有明显下降。重要的是，可以通过使用LS-DIL-G3作为绿色多相催化剂，以克数制得所需的环状碳酸酯。