Synthesis and Functionalization of 3,3′-Bis(spirodienone)-Bridged 2,2′-Bithiophene: A New Building Block for Redox-Active Molecular Switching Materials

Bithiophene derivatives bridged with a bis(spirodienone) unit were synthesized and characterized. Lithiation of the thiophene rings of an unsubstituted derivative proceeded without decomposition of the bis(spirodienone) skeleton. Palladium-catalyzed cross-coupling reactions (Suzuki−Miyaura, Sonogashira) with bromides afforded a variety of π-extended derivatives. Bond breaking and formation under redox conditions were observed by cyclic voltammetry.