Exploiting the Bis-Nucleophilicity of α-Aminoboronates: Copper-Catalyzed, Intramolecular Aminoalkylations of Bromobenzoyl Chlorides.

α-Aminoboronate salts are interesting examples of heteroatomic species containing adjacent nucleophilic centers. We have developed an acylation/arylation reaction using 2-bromobenzoyl chlorides as bis-electrophiles that harnesses the nucleophilicity of both positions, leading to isoindolinones. The reactions proceed under mild conditions via an intramolecular, Cu-catalyzed sp(3)-sp(2) coupling, giving products in up to 95% yield. These conditions enable arylation of α,α-disubstituted aminoboronates, which are difficult to accomplish using methods based on less abundant and more expensive transition metals.