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.

Mild conditions are reported for the hydroxylation of aliphatic C-H bonds through radical translocation, oxidation to carbocation, and nucleophilic trapping with H2O. This remote functionalization employs fac-[Ir(ppy)3] together with Tz(o) sulfonate esters and sulfonamides to facilitate the site-selective replacement of relatively inert C-H bonds with the more synthetically useful C-OH group. The hydroxylation of a range of substrates and the methoxylation of two substrates through 1,6- and 1,7-hydrogen-atom transfer are demonstrated. In addition, a synthesis of the antidepressant fluoxetine using remote hydroxylation as a key step is presented.

Visible-light irradiation of 4-p-methoxyphenyl-3butenylthioglucoside donors in the presence of Umemotos reagent and alcohol acceptors serves as amild approach to Oglycosylation. Visible-light photocatalysts are not required for activation, and alkyl-and arylthioglycosides not bearing the pmethoxystyrene are inert to these conditions.Experimental and computational evidence for an intervening electron donoracceptor complex, which is necessary for reactivity,isprovided. Yields with primary,secondary,and tertiary alcohol acceptors range from moderate to high. Complete b-selectivity can be attained through neighboring-group participation.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under http://dx.

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

Keto furanylidene building blocks are synthesized from the unique silyl ethers of monoalkynylated β-keto carbonyls. The procedure consists of a desilylation, cyclization, and alkyne hydration facilitated by either a one-pot reaction with iron(III) chloride hexahydrate-iodine or a two-step procedure with tosylic acid and gold(I) chloride. Notably, the hydration of the terminal alkyne with iron(III) chloride hexahydrate-iodine reagent is a safer and new alternative to the use of mercury(II) salts.