Desymmetrization of Diboron (4) by a Trifluorination B-Masking Strategy: Practical Synthesis of Unsymmetrical Diboron Species

Herein, we report a straightforward practical and simple method for efficiently synthesizing a BF3- containing unsymmetrical diboron salts. This method involves the direct desymmetrization of commercially available diboron (4). This desymmetrization is based on a selective B-masking strategy via nucleophilic trifluorination, providing the elusive diborons bearing a trifluoroborate group. The synthetic utility of these salts is demonstrated through various examples of (sequen-tial) B-ligand interconversions, enabling the synthesis of unsymmetrical diboron derivatives. These products, which serve as valuable building blocks, are obtained in high yields.