BBDFA: A Practical Reagent for Trifluoromethylation of Allylic and Benzylic Alcohols on Preparative Scale

We report a safe and readily prepared reagent [1,1'-biphenyl]-4-y1 2-bromo-2,2-difluoroacetate (BBDFA) for Cu-catalyzed trifluoromethylation of allylic or benzylic alcohols. An operationally simple and column-chromatography-free process to prepare BBDFA was developed and demonstrated on >100 g scale. Detailed reaction calorimetry and thermal analysis of the deoxytrifluoromethylation were performed using cinnamyl alcohol as a model substrate, demonstrating that the reactions could be safely implemented on preparative scale.