Transition‐Metal‐Mediated Glycosylation with Thioglycosides

Abstract

Thioglycosides are among the most common glycosyl donors that find broad application in the synthesis of glycans and glycoconjugates. However, the requirement for toxic and/or large access of activators needed for common glycosylations with thioglycosides remains a notable draw-back. Due to the increased awareness of the chemical waste impact on the environment, synthetic studies have been driven by the goal of finding non-toxic reagents. The main focus of this review is to highlight recent methods for thioglycoside activation that rely on transition metal catalysis.

Ru‐catalyzed Formation of Thiosilanes and Selenosilanes using Dichalcogenides as a User‐Friendly Alternative to Thiols and Selenols

“…Sulfur‐containing compounds are widespread in chemical synthesis, as they are used in the production of biorelevant molecules and specific materials. The corresponding derivatives containing S−N, S−O, S−C, and S−S moieties are of strategic importance, whilst they exhibit several interesting applications [1–9] . In contrast, thiosilanes (S−Si) remain relatively underexplored despite their usefulness in organic chemistry, [10–13] and the main obstacle in the development of their synthetic potential is still limited ways to access them [14] .…”

“…The corresponding derivatives containing SÀ N, SÀ O, SÀ C, and SÀ S moieties are of strategic importance, whilst they exhibit several interesting applications. [1][2][3][4][5][6][7][8][9] In contrast, thiosilanes (SÀ Si) remain relatively underexplored despite their usefulness in organic chemistry, [10][11][12][13] and the main obstacle in the development of their synthetic potential is still limited ways to access them. [14] To date, the most common procedures for the synthesis of silylthioethers usually involve the use of corrosive chlorosilanes and less easily accessible metal thiolates (Figure 1, a), [15] whereas methods starting from commercially available thiols remain poorly developed.…”

Activation of Thioglycosides with Copper(II) Bromide

“…Glycosyl halides [ 4 , 5 ], glycosyl imidates [ 6 ], and thioglycosides [ 7 ] have become the most prominent glycosyl donors utilized in chemical glycosylation and oligosaccharide synthesis. First synthesized by Fischer in 1909 [ 8 ], thioglycosides are stable towards a majority of protecting group manipulations albeit can be readily activated in the presence of mild thiophilic reagents [ 7 , 9 , 10 , 11 , 12 ]. Among a plethora of known thiophilic promoters, transition metals have been used for decades.…”

Novel triple mutant of an extremophilic glycosyl hydrolase enables the rapid synthesis of thioglycosides

“…[6][7][8][9] Because of the ubiquity and the importance of glycosidic linkages in biology, thioglycosides have found many applications in carbohydrate-based therapeutics, 9 for instance, in the reduction of inflammatory leukocyte accumulation, 10 and have even shown promising anti-tumor effects. 11 A plethora of chemical syntheses to access thioglycosides have been reported, 6,[12][13][14][15][16] however, these procedures require multi-step protecting group strategies and offer limited stereochemical control. 8 Moreover, they often require pre-activation of the donor, toxic reagents and/or catalysts and are mostly performed in organic solvents.…”

“…A plethora of chemical syntheses to access thioglycosides have been reported, 6,12–16 however, these procedures require multi-step protecting group strategies and offer limited stereochemical control. 8 Moreover, they often require pre-activation of the donor, toxic reagents and/or catalysts and are mostly performed in organic solvents.…”