A set of three core-cyanated isoindigos was synthesized by palladium-catalyzed cyanation of core-brominated isoindigos. With decreased LUMO level to -3.88 eV, the dicyanated isoindigo 5 showed ambient-stable electron mobility up to 0.044 cm(2) V(-1) s(-1) in OTFTs with SAMs of TPA, while it exhibited ambipolar charge transport behaviour (0.11 cm(2) V(-1) s(-1) for electrons and 0.045 cm(2) V(-1) s(-1) for holes) on FOPA-modified substrates.