Under mild conditions, Beckmann rearrangement of a variety of ketoximes could proceed in the presence of chlorosulfonic acid using toluene as a solvent with excellent conversion and selectivity. This procedure could also be applied in the dehydration of aldoximes for obtaining the corresponding nitriles.

★★★★☆ D. Li et al. / Tetrahedron Letters 46 (2005) 671–674.

Several acid-functional ionic liquids were physically confined into the silica gel through a sol–gel process and used as effective catalysts for deoximation reactions, which proceeded under ambient temperatures without addition of any co-catalysts or oxidizing and reducing agents.

★★★★☆ D. Li et al. / Tetrahedron Letters 45 (2004) 265–268.

Several acid functional ionic liquids, in which cations possess two adjacent acid sites, were synthesized and used for the acetalization of aldehydes with good catalytic performance under mild reaction conditions.

★★★★☆ Dongmei Li, Feng Shi, Jiajian Peng, Shu Guo, and Youquan Deng. J. Org. Chem. 2004, 69, 3582-3585.

At ambient reaction temperature, the silica gel confined ionic liquid catalysts were perfectly combined with water as an effective catalytic system for simultaneous C@N and C@O bonds transformation with a TONs exceeding 300molmol
-1.

★★★★☆ D. Li et al. / Tetrahedron Letters 45 (2004) 6791–6794.