Iron(iii) chloride modulated selective 1,2-trans glycosylation based on glycosyl trichloroacetimidate donors and its application in orthogonal glycosylation

Abstract

FeCl3 modulated excellent 1,2-trans selective glycosylations based on trichloroacetimidate glycosyl donors even in the presence of apparently silent C-2 protecting group, along with orthogonal glycosylation reactions are reported.

A Stereoselective Glycosylation Approach to the Construction of 1,2‐trans‐β‐d‐Glycosidic Linkages and Convergent Synthesis of Saponins

“…Indeed, several Lewis acids capable of effecting the 1,2‐ trans ‐β‐selective glycosylation with glycosyl α‐trichloroacetimidate donors have been identified. Those include AuCl 3 , [24] PtCl 4 , [25] Pd(PhCN) 2 (OTf) 2 /Pd(CH 3 CN) 4 (BF 4 ) 2 , [26] and FeCl 3 , [27] as reported by the research groups of Schmidt, Peng, Nguyan, and Ghosh, respectively.…”

Synthetic Routes toward Acidic Pentasaccharide Related to the O-Antigen of E. coli 120 Using One-Pot Sequential Glycosylation Reactions

“…A mixture of thioglycoside donor 10 and glycosyl acceptor p -methoxyphenyl 3,4,6-tri- O -benzyl-α- d -galactopyanoside 11 in dry DCM at 0 °C was treated with NIS and FeCl 3 to produce disaccharide 6 in 92% yield. The NMR spectra of disaccharide 6 showed signals characteristic of the presence of both donor and acceptor moieties, while an α-configuration of the interglycosidic linkage was confirmed from the corresponding 1 H (δ 5.01, H 1 ′, J 1,2 = 0.8 Hz) and 13 C NMR (δ 97.8) spectra.…”

Direct Sulfoxidation of Aromatic Methyl Thioethers with Aryl Halides by Copper-Catalyzed C(sp3)–H Bond Activation

“…In particular, benzylsulfoxide derivatives exhibit a wide range of biological properties, such as anti-bacterial activity (Scheme 1I) [4], anti-cancer activity (Scheme 1II) [5], and HIV inhibition (Scheme 1III) [6]. The most common synthetic method for benzylsulfoxide derivatives is sulfide oxidation, as illustrated in Scheme 2A [7]. The strong oxidizing agents and reactive organolithium contribute to the wide use of this method, although its scope is limited.…”

“…Therefore, the development of an efficient and less stringent reaction route for the synthesis of benzylsulfoxides remains highly desirable. The most common synthetic method for benzylsulfoxide derivatives is sulfide oxidation, as illustrated in Scheme 2A [7]. The strong oxidizing agents and reactive organolithium contribute to the wide use of this method, although its scope is limited.…”