Reactions with and in anhydrous hydrogen fluoride systems. Part 8. Triethylamine trishydrofluoride — a convenient reagent for the stereoselective synthesis of glycosyl fluorides

Strategien zur Erforschung neuer Reaktionen

“…Zur Herstellung von Glycosylfluoriden [105] ist eine Vielzahl von Fluorierungsreagentien entwickelt worden, z. B. HF, [106] 2-Fluor-1-methylpyridiniumtosylat, [107] Diethylaminoschwefeltrifluorid (DAST), [108][109][110] HF/Pyridin, [111][112][113] CF 3 ZnBr/TiF 4 , [114] DEAD/PPh 3 /Et 3 O·BF 4 , [115] Selectfluor, [116] Deoxofluor, [117] N,N-Diisopropyl(1-fluor-2-methyl-1-propenyl)amin, [118] HF/MeCN/Ac 2 O, [119] AgF, [120] ZnF 2 , [121] Et 3 N-HF, [122] CF 3 ZnBr, [114] DAST/N-Bromsuccinimid(NBS)/N-Iodsuccinimid(NIS) [123,124] 4-Methyl(difluoriod)benzol, [125] TBAF [126] und PhI(OAc) 2 /SiF 4 . [127] Am häufigsten angewendet werden DAST, HF/Pyridin und DAST/NBS.…”

Explorations into New Reaction Chemistry

“…The notable advantage of a glycosyl fluoride as a glycosyl donor is its higher thermal and chemical stability relative to glycosyl chlorides, bromides, and iodides; it is possible to purify glycosyl fluorides by column chromatography on silica gel. Many methods for the preparation of glycosyl fluorides105 have been developed by using various fluorinating reagents such as HF106 2‐fluoro‐1‐methylpyridinium tosylate,107 diethylaminosulfur trifluoride (DAST),108–110 HF/pyridine,111–113 CF 3 ZnBr/TiF 4 ,114 DEAD/PPh 3 /Et 3 O⋅BF 4 ,115 selectfluor,116 deoxofluor,117 N , N ‐diisopropyl(1‐fluoro‐2‐methyl‐1‐propenyl)amine,118 HF/MeCN/Ac 2 O,119 AgF,120 ZnF 2 ,121 Et 3 N/HF,122 CF 3 ZnBr,114 DAST/ N ‐bromosuccinimide (NBS)/NIS,123, 124 4‐methyl(difluoroiodo)benzene,125 TBAF,126 and PhI(OAc) 2 /SiF 4. 127 Of these, DAST, HF/pyridine, and DAST/NBS are most frequently used.…”

Modified natural substances—fluorinated and fluoroalkylated monosaccharides and inositols

“…Silver fluoride is the most commonly used reagent for this purpose [2]. We could show that glycosyl bromides form glycosyl fluorides with inverted configuration at the anomeric center by heating the bromides in a two phase system from triethylamine tris(hydrogen fluoride) and CCl 4 [29][30][31]. …”