Photo-induced glycosylation using the edible polyphenol curcumin.

Photo-induced glycosylations of trichloroacetimidate donors and alcohols using an edible polyphenol, curcumin, were examined under visible photo-irradiation (470 nm). It was found, for the first time, that these glycosylations proceed smoothly under mild reaction conditions to give the corresponding glycosides in high yields. In addition, the present glycosylation method was applicable to a wide range of trichloroacetimidate donors and alcohol acceptors and showed high chemoselectivity over glycosyl phosphite, phosphate, (N-phenyl)trifluoroacetimidate, fluoride, glycal and thioglycoside.