Herein, we present a highly efficient and convenient approach for carbon dioxide (CO₂) capture and catalytic transformation under mild conditions using N,N′-bis(imidazolyl)guanidines (BIGs, organoguanidine-based strong superbases) as the organocatalyst, even from simulated flue gas (10% CO₂/90% N₂, v/v) or directly from dry air (∼400 ppm CO₂). The zwitterionic BIG–CO₂ adducts were successfully isolated and characterized. X-ray single crystal analysis revealed the bent geometry of the binding CO₂ in the BIG–CO₂ adduct with an O–C–O angle of 129.7° and increased C–O bond distances (1.253 and 1.237 Å) in comparison with free CO₂. Notably, the resulting BIG–CO₂ adducts were found to be capable of catalyzing the novel cycloaddition of various propiolamidines with simulated flue gas to generate functionalized (4E,5Z)-4-imino-5-benzylideneoxazolidine-2-ones in good yields and excellent selectivity.

中文翻译：

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超碱性胍对低浓度二氧化碳的高效捕获和随后的催化转化

在这里，我们提出了一种高效，便捷的方法，可在温和条件下使用N，N'-双（咪唑基）胍（BIGs，基于有机胍的强超强碱）作为有机催化剂，捕获和催化转化二氧化碳（CO ₂）。模拟烟气（10％CO ₂ /90％N ₂，v / v）或直接来自干燥空气（〜400 ppm CO ₂）。两性离子BIG-CO ₂加合物已成功分离和表征。X射线单晶分析显示BIG–CO _2中结合的CO ₂的弯曲几何形状与游离CO ₂相比，OC夹角为129.7°的C-O键距离增加（1.253和1.237Å）。值得注意的是，发现生成的BIG-CO ₂加合物能够催化各种烟酰胺与新型丙prop胺的新型环加成反应，从而以良好的方式生成功能化的（4 E，5 Z）-4-亚氨基-5-苄叉二氧恶唑烷-2-酮。产率和优异的选择性。