The work demonstrates trivalent tris-(3-N-methyl-N-pyridyl propyl)amine (1) catalyzing the site-selective mono-O-acylations of glycopyranosides. Varied acid anhydrides are used for the acylations of monosaccharides, mediated by the catalyst 1, at a loading of 1.5 mol%, the extent of site-selectivity and the yields of mono-O-acylation products are assessed. The reactions are performed between 2 and 10 h, depending on the nature of the acid anhydride, where bulkier pivalic anhydride requires longer duration for the acylations. The glycopyranosides are maintained as diols and triols, and from a set of experiments, the site-selectivity of acylations is observed to follow the intrinsic reactivities and stereochemical dispositions of the hydroxy functionalities. The trivalent catalyst 1 mediates the reactions with excellent site-selectivities for mono-O-acylation product formation in the studied glycopyranosides, in comparison to monovalent N,N-dimethylamino pyridine (DMAP) catalyst. The study illustrates the benefits of multivalency of catalytic moieties in catalysis.

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