Bromoform activation. TiCl4-Mg-promoted CHBr2- and CBr3- transfer to a variety of aldehydes and ketones.

TiCl4-Mg can mediate addition of CHBr3 to a variety of aldehydes and ketones to form dibromomethyl carbinols and also be used to effect CBr3 transfer to carbonyl groups to form tribromomethyl carbinols. The successful application of TiCl4-Mg-promoted coupling of CHBr3 with various carbonyl compounds, especially in the case of highly enolizable ketones such as 2-indanone and β-tetralone, highlights the extraordinary reactivity and selectivity and the weakly basic nature of this system.