N-Sulfonic acid poly(4-vinylpyridinum) hydrogen sulfate as a novel, efficient, and reusable solid acid catalyst for acylation under solvent-free conditions

N-Sulfonic acid poly(4-vinylpyridinum) hydrogen sulfate has been developed as a recyclable solid acid catalyst for the acetylation of alcohols, phenols, thiols, and amines, as well as the 1,1- diacetylation of aldehydes under solvent-free conditions at room temperature. The acetylated products were formed in good to excellent yields over short reaction times, and the catalyst could be readily recovered by filtration and used several times without any discernible loss in activity. The hydrogen sulfate anion of the catalytic system was found to play a critical role in enhancing the reaction time and yield of the acetylation reaction.

Graphical AbstractPoly(4-vinylpyridinium) hydrogen sulfate (NSPVPHS) has been developed as a new recyclable solid acid catalyst for the acetylation of alcohols, phenols, thiols, and amines, and the 1,1-diacetylation of aldehydes under solvent-free conditions at room temperature. The acetylated products were obtained in good to excellent yields over short reaction times without the formation of any side products. The hydrogen sulfate anion was determined to be critical to enhancing the reaction time and product yield.Figure optionsDownload as PowerPoint slide