Synthesis and Characterization of Novel Oligoazulenes with Mixed Ethynyl and Butadiynyl Bridges

The new oligoazulenes 10–14 with mixed ethynyl and butadiynyl bridges were synthesized by oxidative Eglinton coupling from the readily accessible ethynylazulenes 3, 4, 7, 9 and 15 as well as by Pd/Cu-catalyzed cross-coupling reactions with the appropriate iodoazulenes 5, 6 and 8.