A Cu(OTf)2-Catalyzed Glycosylation with Glycosyl Ortho-N-phthalimidoylpropynyl Benzoates As Donors.

A Cu(OTf)2-catalyzed glycosylation protocol using glycosyl ortho-N-phthalimidoylpropynyl benzoates (NPPBs) as donors was disclosed, which features an inexpensive copper catalyst, operationally convenient conditions, high to excellent yields, and a broad substrate scope. Mechanistic studies indicated an isochromen-4-yl copper(II) intermediate arising from the departure of the leaving group.