1. Polyoxometalate-based ionic liquids: efficient reversible phase transformation-type catalysts for thiolation of alcohols to construct C–S bonds.
- Author
-
Li, Jikun, Ma, Junwei, Wei, Chuanping, Zheng, Zebao, Han, Yinfeng, Wang, Huiping, Wang, Xueshen, and Hu, Changwen
- Subjects
IONIC liquids ,HETEROGENEOUS catalysts ,CATALYTIC activity ,CATALYSTS ,BENZYL alcohol ,IMIDAZOLES ,COUPLING reactions (Chemistry) - Abstract
As important building blocks in natural products and organic synthesis, thioethers have a wide range of potential applications. Herein, polyoxometalate-based ionic liquids (POM-ILs-SO
3 H) derived from N-alkyl imidazole were synthesized and used for the first time for the thiolation of alcohols to construct C–S bonds in a series of benzyl thioethers. This type of POM-ILs-SO3 H catalyst exhibited high catalytic activity, providing up to 98% yield of thioether within 1 h at 70 °C. The alkyl chain length of the imidazole had a certain effect on the solubility of the POM-ILs-SO3 H catalysts in the reaction solvent, and then affected their catalytic activity. The catalytic system had a wide substrate scope and was suitable for the reaction of tertiary and secondary benzyl alcohols with thiophenols or cycloalkyl thiols. In particular, [PIMPS]3 PW12 O40 (PIM = 1-propylimidazole, PS = propane sulfonate) as a reversible phase transformation-type catalyst, combining the advantages of homogeneous and heterogeneous catalysts, exhibited high activity and good recyclability with only a slight decrease in the yield after five runs. Additionally, a carbocation mechanism was proposed for the thiolation reaction of alcohols. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF