Copper-Catalyzed Borylation of Styrenes by 1,8-Diaminonaphthalene-Protected Diboronic Acid.

We report a concise synthesis of 1,8-diaminonaphthalene-protected diboronic acid (B(dan)), which is a promising borylating agent. B(dan) is a bench-stable compound, and it could be utilized for Cu-catalyzed borylation of styrene derivatives. The reaction proceeded in a highly selective manner, and the products were isolated in up to 97% yields. Mechanistic studies revealed that a borate species would be a key intermediate for the borylation reaction.