Polyvinyl trisulfonate ethylamine based solid acid catalyst for the efficient glycosylation of sugars under solvent free conditions†
Abstract
Heterogeneous Brønsted solid acid catalysts have the potential to decrease the environmental impact related to chemical production. Herein, we have synthesized polyvinyl bound trisulfonate ethylamine chloride (PV-THEAC) and polyvinyl bound disulfonate ethylamine (PV-DSEA) as Brønsted solid acid catalysts which exhibited effective catalytic activity for acid catalyzed glycosylation reactions with sugar derivatives. In particular, 0.3 equiv. of the PV-THEAC catalyst was found to be the most efficient and a reusable catalyst for glycosylation reactions. A high density of the trisulfonic group (–OSO3H) contributed to the excellent catalytic activity during glycosylation. Moreover, glycosylation reactions with D-mannose, D-xylose and D-glucose have been studied with alcohol. Remarkable acceleration of the glycosylation reaction using a glycosyltrichloroacetimidate donor was obtained with the selective production of β-glycoside.