Palladium‐Catalyzed Double Ullmann Reaction: An Approach towards Tetraphenylenes

Abstract A palladium‐catalyzed double Ullmann coupling reaction for the preparation of tetraphenylenes has been developed. With this protocol, twelve tetraphenylene derivatives were synthesized from the corresponding 2,2′‐diiodobiaryls directly with the yields ranging from 13–51 %. Insights into the mechanism of these palladium‐catalyzed double coupling reactions are discussed, and the findings are expected to increase the level of understanding of palladium‐catalyzed formation of carbon–carbon bonds within rigid molecular frameworks.