作者:Chao-Wen Chen、Ming-Chung Tseng、San-Kai Hsiao、Wen-Hao Chen、Yen-Ho Chu
DOI:10.1039/c0ob01094d
日期:——
Compared to conventional molecular solvents, the ionic liquid [b-3C-im][NTf2] was found to promote transimination reactions with up to ∼100-fold rate enhancement. This rate effect observed at ambient temperature might be explained by the fact that the ionic liquid displays weak Lewis acidity with very low, if any, nucleophilicity and its imidazolium cation is expected to interact by associating with, and thus electrophilically activating, the CN bond of the starting imine, leading to increased stabilization of the polar, charged intermediate species and ultimately, rapid product formation. Moreover, the presence of 1 mol% Sc(OTf)3 in [b-3C-im][NTf2] further facilitates the transimination reactions studied.
与传统分子溶剂相比,[b-3C-im][NTf2]离子液体可促进反硝化反应,其速率可提高 100 倍。在常温下观察到的这种速率效应可能是由于离子液体显示出弱路易斯酸性,亲核性极低(如果有的话),其咪唑阳离子预计会与起始亚胺的 CN 键结合,从而亲电激活 CN 键,导致极性带电中间产物更加稳定,最终快速形成产物。此外,[b-3C-im][NTf2] 中 1 mol% 的 Sc(OTf)3 的存在进一步促进了所研究的反硝化反应。