Copper(II) Triflate: A Versatile Catalyst for the One-Pot Preparation of Orthogonally Protected Glycosides

The development of general and expedient methodologies for the preparation of orthogonally protected glycoside building blocks is essential for the efficient synthesis of complex oligosaccharides. Herein, we describe a new approach that uses copper(II) triflate as a versatile catalyst for the one-pot preparation of orthogonal protected thio- and O-glycosides from the corresponding unprotected counterparts. The conditions are mild, easy to handle and applicable to two and three one-pot tandem transformations, which include arylidene acetalation, esterification, regioselective reductive acetal ring opening, glycosylation and silylation processes.