CuBr2/TBHP-Promoted Selective Dibromination and Bromohydroxylation of (Diphenylphosphoryl)allenes

A cooperative CuBr2 and tert-butyl hydroperoxide (TBHP) system allowed for the highly stereoselective dibromination and bromohydroxylation reactions of (diphenylphosphoryl)allenes under mild (room temperature) and operationally simple conditions. These reactions selectively proceeded through either a dibromination or bromohydroxylation process and are characterized by their broad substrate scope (22 examples), their step economy, and ability to be carried out on a gram scale. This method offers a useful protocol to access allyl bromides and alcohols. Moreover, synthetic applications of the dibromination products include a Suzuki-Miyaura cross-coupling reaction and copper-catalyzed cascade process, which could also afford various important derivatives.