Abstract We report that instead of using CBr 4, CHBr 3 can serve as a highly nucleophilic dibromomethylene carbenoid in chemoselective carbonyl dibromomethylenation. Successful application of the dibromomethylenation to various carbonyl compounds such as enolizable and sterically hindered ketones by using the CHBr 3/Mg/TiCl 4 system highlights the weakly basic nature, extraordinary reactivity, and synthetic versatility of the approach.
