Novel Non‐toxic and Non‐hazardous Solvent Systems for the Chemistry of Indoles: Use of a Sulfone‐containing Brønsted Acid Ionic Liquid Catalyst in Butyl Acetate
作者:Ahmed El‐Harairy、Yiliqi、Meie Yue、Weigang Fan、Florence Popowycz、Yves Queneau、Minghao Li、Yanlong Gu
DOI:10.1002/cctc.201900784
日期:2019.9.5
Dipolar and aprotic solvents are often required in acid‐catalyzed reactions, however, many of them are listed in solvent selection guides as not‐recommended due to their toxicity or explosivity. A catalytically functionalized ionic liquid, namely a sulfone‐containing imidazolium‐based Brønsted acid ionic liquid, was synthesized. It alleviates the detrimental effect of classical dipolar aprotic solvents
酸催化反应中通常需要偶极和非质子溶剂,但是由于其毒性或爆炸性,在溶剂选择指南中列出了许多不推荐的溶剂。合成了一种催化功能化的离子液体,即含砜的咪唑基布朗斯台德酸离子液体。它减轻了传统偶极非质子溶剂的有害作用,因为这种离子液体整合了能够稳定碳正离子中间体的偶极非质子溶剂的功能以及强布朗斯台德酸对亲电子试剂的活化作用。这种定制的离子液体的使用在吲哚的某些转化反应中得到了体现,该反应使用绿色且工业上可接受的溶剂乙酸丁酯以高收率和选择性进行。