Benzyl sulfane

Ammoniumsalz) und Chlormethyl-benzyl-sulfan in Butanon XII/2, 653 -(3-benzyl-thioureid)-0,0-diethylester XII/2, 798 -O-2-biphenylylester-hydrazid-O-methvlcster XII/2, 802... 

Bei der Reduktion von Dialkyl- und Benzyl-sulfoxiden mit Trichlorsilan in Ather wird ein Gemisch aus Thioacetal und Sulfan erhalten3, in der Gegenwart von a. -Wasserstoff-Atomen lauft also die Reduktion unter Spaltung und Rekombination des Molekiils ab. Dementsprechend werden Diaryl-sulfoxide in Ather praktisch quantitativ zu Sulfanen re-duziert (z.B. Diphenyl-sulfoxid zu Diphenyl-sulfid mit 98% d.Th.). 

In sharp contrast to the reactivity of sulfur tetrafluoride (see Sections 8.1.-8.3,), (dia-lkylamino)lrifluoro->l4-sulfanes convert alcohols to their corresponding fluorides under mild conditions, generally at temperatures between room temperature and — 78 C. Aliphatic, allylic, acetylenic, benzylic, and amino alcohols have been converted to fluorides in good yields. 

DAST (1) and the related aminofluoro-/ -sulfanes convert primary, secondary, tertiary, allylic and benzylic alcohols into fluorides under mild conditions in high yield with little byproduct formation. In this respect they are superior to most other fluorinating agents. DAST (1) and other aminofluoro-2 -sulfanes can fluorinatc hydroxy acids and hydroxy ketones selectively to give the corresponding fluoro acids and fluoro ketones, which is impossible or, at least, diflicult w ith sulfur tetrafluoride. 

---