Bidirectional Synthesis of C2-Symmetric Unilateral Substituted Acenes: 1,10,11,12-Tetrafluorotetracene.

The efficacy of a bidirectional synthesis for C2-symmetric acenes was demonstrated for 1,10,11,12 tetrafluorotetracene. Starting from a central naphthalene, 2-fold Suzuki cross-coupling reactions attached lower side chains to the left and right sides simultaneously. Two fluorine substitutents were introduced via MOM-directed lithiation. The Suzuki attachment of the upper fluoroalkenyl side chains required the use of a latent alkene in the lower chain. Double fluoroalkene ring-closing metathesis installed two outer six-membered rings simultaneously. Final double dehydroaromatization was achieved using trityl tetrafluoroborate.