Supported ionic liquid phase catalysis for aerobic oxidation of primary alcohols

The copper-TEMPO-catalysed aerobic oxidation of primary alcohols based on the new supported ionic liquid phase (SILP) catalysts is presented. CuCl2 acts as a homogenous catalyst dissolved in the small quantity of ionic liquid dispersed in the form of film on the solid support. A bi-modal pore structure silica with a highly developed surface and an ionogel were used as solid supports. 1-Butyl-3-methylimidazolium octylsulfate as the most active “catalyst-philic” phase was found. The application of SILP catalysts for the oxidation of alcohols allows the high yields of corresponding aldehydes (92–95%). The catalysts were used in seven cycles without significant loss of activity. High recoveries of the catalysts were observed.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (49 K)Download as PowerPoint slideResearch highlights▶ Method for the oxidation of alcohols to aldehydes with high yields and selectivities. ▶ Concept of supported ionic liquid phase catalysis with dissolved CuCl2. ▶ Halogen-free ILs like [bmim]OSO3Oc as the “catalyst-philic” phase, supported on ionogel. ▶ Effective recycle of catalyst is possible.