TAS-F

Physical properties

R = Me, mp 98–101 °C; R = Et, mp 90–95 °C.

The Uses of TAS-F

Tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF₂SiMe₃) can be used as a mild deprotecting reagent for the cleavage of silicon protecting groups.
It can also be used

• To synthesize deoxyfluoro sugars by reacting with trifluoromethanesulfonyl derivatives of partially protected sugars.
• As a reagent for the fluorination of hydroxyl-containing compounds.

The Uses of TAS-F

Tris(dimethylamino)sulfonium Difluorotrimethylsilicate is used in anhydrous fluoride ion source; synthesis of C–F compounds by nucleophilic displacement of sulfonates;promoter for electrophilic reactions of silyl enolates of ketones and esters; source of sulfonium cation capable of stabilizing or imparting high nucleophilic reactivity to other anions; activator of vinylsilanes in Pd-catalyzed cross-coupling reactions; also used for generation8 and reactions of α- and β-halo carbanions; hydrosilylation and cyanomethylation of ketones.

Preparation

The methyl derivative is prepared by the reaction of dimethylaminotrimethylsilane and sulfur tetra- fluoride at ?70°C to rt in ether; the precipitated solid is filtered off.1a The ethyl derivative is best prepared by the reaction of N,N-diethylaminosulfur trifluoride (DAST) and diethylaminotrimethylsilane.

General Description

Tris(dimethylamino)sulfonium difluorotrimethylsilicate is widely used in organic synthesis as a source of fluoride ion for the synthesis of fluorinated compounds by C-F bond formation. It is also used as a reagent in hydrosilylation, cyanomethylation of ketones and Pd-catalyzed cross-coupling reactions.