Тетрабутиламмоний трибромид

Химические свойства

Insoluble in H2O; soluble in anhydrous acetic acid (50 g/100 mL), MeCN (300 g/100 mL), CHCl3, trichloroethylene (10 g/100 mL), THF, dioxane; very soluble in DMF, DMSO; slightly soluble in alcohols; soluble in acetone with slow reaction, giving lachrymatory solution. Avoid washing reaction vessels with acetone prior to using this reagent. It should be handled in a fume hood. Anhydrous, orange nonhygroscopic stable solid; purity more than 98%; stable bromine degree (1 g = 2.07 mequiv Br2). Red crystals when recrystallized from DMF solution.

Использование

1. Tetrabutylammonium tribromide (TBATB) is a salt of the lipophilic tetrabutylammonium cation and the linear tribromide anion. It is used as a phase transfer catalyst in organic synthesis as well as a mild brominating agent. A wide range of O-isopropylidene derivatives can be prepared from the sugars and their derivatives on reaction with acetone at room temperature by employing 2 mol % of tetrabutylammonium tribromide as a catalyst. Good yields, low catalyst loading, mild reaction conditions, and a non-aqueous workup procedure are some major advantages of this protocol.
2. Tetrabutylammonium tribromide as an efficient generator of HBr for an efficient chemoselective reagent for acetalization of carbonyl compounds.
   
3. It is sometimes used as a reagent used in organic synthesis as a conveniently weighable, solid source of bromine.
4. Tetra-n-butylammonium tribromide is useful for the preparation of vicinal dibromides from alkenes and alkynes and alfa-bromo acetals.
5. it is utilized to generate hydrogen bromide, which is used as an efficient chemoselective reagent for acetalization of carbonyl compounds.