Palladium‐Catalyzed Cross‐Coupling Reaction of Thioglycosides with (Hetero)aryl Halides

Abstract

a-and b-thioglycosides serve as effective nucleophiles for Buchwald-Hartwig cross-coupling reactions using functionalized (hetero)aryl halides. The functional group tolerance on the electrophilic partner is typically high, both benzyl and acetate protecting groups on the carbohydrate are tolerated, and anomer selectivities of thioglycosides are high in all cases studied. The efficiency of this general protocol was well demonstrated by the synthesis of 4methyl-7-thioumbelliferyl-b-d-cellobioside (MUS-CB).

Transition-Metal-Catalyzed C–S, C–Se, and C–Te Bond Formations via Cross-Coupling and Atom-Economic Addition Reactions. Achievements and Challenges

“…170 Alami and co-workers realized classical Pd catalysis, according to Buchwald−Hartwig, in the reaction of aryl-(heteryl)halogenides (X = I, Br) with thioglucosides (Scheme 13). 171 In a screening of various bidentate and monodentate ligands, Pd(OAc) 2 -Xantphos-Et 3 N demonstrated the best results. Under these conditions, 22 hetero(aryl)halogenides were introduced into the reaction with β-thioglucose, and the yields were in the range of 72−99%, with the exception of (2R,3R,4S,5R,6S)-2-(acetoxymethyl)-6-[(4-nitrophenyl)thio]tetrahydro-2H-pyran-3,4,5-triyl triacetate (61%).…”

Pd-catalyzed functionalization of benzo-2,1,3-thiadiazole at the C-5-position using 1-thiosugars

“…19 Messaoudi and Alami performed a palladium-catalyzed C-S cross-coupling reaction with a wide variety of (hetero)aryl halides (Scheme 1a) using Pd(OAc) 2 /Xantphos as the catalytic system. 3 Continuing our interest in developing novel and efficient methodologies for the C-S cross-coupling reaction, 20,21 we synthesized benzo-2,1,3-thiadiazole derivatives using b-glycosyl thiols as the nucleophiles. Recently, our research group described a protocol for the C-5 functionalization of the BTD unit catalyzed by Pd(L-Pro) 2 (Scheme 1b) using different thiophenols.…”

“…1,2 1-Thioglycoside derivatives have been considered as the mimetics of biologically important O -glycosides. 3 In addition, a thiosugar moiety has been found in several drugs, natural products, and biologically active agents, including the hSGLT1 inhibitor, the ligand of lectine A, and galactosidase and glycosidase inhibitors (Fig. 1).…”

“…19 Messaoudi and Alami performed a palladium-catalyzed C–S cross-coupling reaction with a wide variety of (hetero)aryl halides (Scheme 1a) using Pd(OAc) 2 /Xantphos as the catalytic system. 3…”

Visible-Light-Mediated Stadler–Ziegler Arylation of Thiosugars with Anilines

“…Due to their key role in many biological processes, the development of methods toward an efficient and stereoselective synthesis of 1-arylthioglycosides is considered to be of great importance. , A well-known strategy largely applied toward these target S -arylated glycosides is the cross-coupling reaction typically catalyzed by the Pd, − Ni, Cu − transition metals, in which an aryl halide reacts with a glycosyl thiols leading to the desired thioglycoside derivative (Figure C). Despite their high interest, these methods required the use of expensive catalysts or a high temperature and a long reaction time, limiting thus the practicability or the scope of substrates.…”