Vicinal Vinylation of Boron-Doped Acenes via Heck Coupling

Silylated and halogenated benzenes 1,2-(Me₃Si)₂-4,5-X₂-C₆H₂ [X = Br (3), I (4)] are versatile synthetic building blocks. 3 was prepared from known 1,2-(Me₃Si)₂-4,5-Cl₂-C₆H₂ via C–Cl borylation/bromodeboronation; CuI-catalyzed Br/I exchange on 3 affords 4. 3 or 4 and BBr₃ yield 9,10-dibromo-9,10-dihydro-9,10-diboraanthracenes (DBAs) 7 or 8. The B centers were protected with mesityl (Mes; 9, 10) or 2,4,6-tris(trifluoromethyl)phenyl (^FMes; 11, 12) groups. Heck coupling of 9 and styrene/2,3,4,5,6-pentafluorostyrene furnishes the two tetravinyl-substituted green/blue emitters 13/14.