HALIDE EXCHANGE AND REDUCTION OF PHENACYLHALIDES PROMOTED BY AQUEOUS TITANIUM(III) SALTS AT VARIOUS pHs. MECHANISTIC CONSIDERATIONS.

Article abstract of DOI:10.1016/S0040-4039(01)81037-6

While aqueous Ti2(SO4)3 is an efficient reagent in acidic medium for selective debromination of phenacylbromide 1 to acetophenone 3 in the presence of phenacylchloride 2, aqueous TiCl3 gives mostly halide exchange 1 -> 2.In neutral medium, both aqueous Ti2(SO4)3 and TiCl3 bring about dehalogenation of 1 and 2 to 3 in less than one minute at room temperature.In basic medium, reduction of 1 and 2 goes further to methylphenylcarbinol 4.