Bromation régiosélective en série aromatique. I: Monobromation en position para de phénols et d'aminés aromatiques par le tribromure de tétrabutylammonium

The reaction of tetrabutylammonium tribromide (TBABr 3 ) with phenols and aromatic amines in aprotic and non-basic solvents at 20 °C gives exclusively the corresponding para-brominated compounds in high yields. A mechanism involving electrophilic substitution by the tribromide anion Br 3 − itself is suggested to account for the results, especially the regioselective para bromination.