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O-Glycosylation is a critically important and recurring step in the synthesis of oligosaccharides and other natural and non-natural products. While many approaches to O-glycosylation have been reported, those strategies involving remote activation are distinguished by the mildness and orthogonality that they often engender. As a result, O-glycosylation using remote activation strategies has been utilized successfully in the synthesis of complex molecules that include oligosaccharides and macrolides. Herein, we discuss a number of contributions that have been made to this area since the 1970s. This includes our own recent contribution involving the visible-light activation of 4-pmethoxyphenyl- 3-butenylthioglycosides toward O-glycosylation in the presence of Umemoto's reagent. 1 Introduction 2 Fraser-Reid's Development of n-Pentenylglycosides as Glycosyl Donors 3 Hanessian's Remote Activation of 2-Pyridylthioglycosides 4 Gold-Catalyzed O-Glycosylation (Hotha and Yu) 5 Wan's 'Interrupted Pummerer' Approach to O-Glycosylation 6 O-Glycosylation with 4-p-Methoxyphenyl-3-butenylthioglycosides 7 Conclusions. [ABSTRACT FROM AUTHOR]

Visible-light irradiation of 4-p-methoxyphenyl-3-butenylthioglucoside donors in the presence of Umemoto's reagent and alcohol acceptors serves as a mild approach to O-glycosylation. Visible-light photocatalysts are not required for activation, and alkyl- and arylthioglycosides not bearing the p-methoxystyrene are inert to these conditions. Experimental and computational evidence for an intervening electron donor-acceptor complex, which is necessary for reactivity, is provided. Yields with primary, secondary, and tertiary alcohol acceptors range from moderate to high. Complete β-selectivity can be attained through neighboring-group participation., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)