The rapid synthesis of deoxyfluoro sugars using tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF)

Abstract

. 65, 412 (1987). Deoxyfluoro sugars were synthesized rapidly by the reaction of trifluoromethanesulfonyl derivatives of partially protected sugars with tris(dimethylarnino)sulfonium difluorotrimethylsilicate (TASF) under mild conditions. The displacements occurred with inversion of configuration; fluorine has been introduced stereospecifically at each of the secondary alcoholic sites of aldohexopyranosides and in one example of a furanoid system. In some instances unsaturated compounds that contained no fluorine were produced. BOGDAN DOBOSZEWSKI, GEORGE W. HAY et WALTER A. SZAREK. Can. J. Chem. 65,412 (1987). On a realist une synthkse rapide de sucres dtsoxyfluorCs en faisant rCagir des derives trifluoromCthanesulfonylCs de sucres partiellement proteges avec du difluorotrimCthylsilicate de tris(dimCthy1amino)sulfonium (TASF), utilisant des conditions douces. Les reactions de deplacement se font avec inversion de configuration; on a pu introduire d'une facon spkcifique des atomes de fluor au niveau de chacun des sites alcooliques secondaires des aldohexopyrannosides et dans un exemple de systtme furannoide. Dans quelques cas, on a obtenu des compos6s insatures qui ne contenaient pas de fluor.[Traduit par la revue]

Synthesis of Phosphonoglycine Backbone Units for the Development of Phosphono Peptide Nucleic Acids

“…The use of a triflate derived from 23 rather than tosylate 24 makes substitutions much easier. [37][38][39] The azide 25 was reduced to the amine 26 in nearly quantitative yield by using Staudinger conditions. The same compound was previously obtained by using catalytic hydrogenation [36] of 25 or lithium aluminum hydride reduction of the corresponding 6-oxime.…”

Facile synthesis of 4-deoxy-4-fluoro-α-d-talopyranoside, 4-deoxy-4-fluoro-α-d-idopyranoside and 2,4-dideoxy-2,4-difluoro-α-d-talopyranoside

“…The introduction of the fluorine substituent at C-2 was first attempted with 2 equiv. of tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF)/pyridine [18] in CH 2 Cl 2 /MeCN. No reaction occurred after 24 h at 40 8C.…”

Synthesis of Fluorinated Sphinganine and Dihydroceramide Analogues

“…However, reduction of alkyne 13 by catalytic hydrogenation to its saturated counterpart proved to be cumbersome. Alternatively, a two-step sequence was attempted involving reaction with tris(dimethylamino)sulfur (trimethylsilyl)difluoride (TASF) [24] subsequent to transformation of alcohol 11 to the triflate. However, reaction of 11 with trifluoromethanesulfonic anhydride did not afford a triflate, but cleavage of the oxazolidine and intramolecular cyclization gave cyclic urethane 14 in near quantitative yield.…”