Regioselective Synthesis and Photophysical Properties of 2,7-Functionalized 1,3,6,8-Tetraethynylpyrenes

We report a facile synthesis of regioselectively multi-functionalized pyrenes through one-pot reactions. These reactions involve Stille and Suzuki coupling reactions, which are proven effective in forming 1,2,3,6,7,8-hexaphenylethynylpyrene for the first time. The 1,3,6,8-tetraphenylethynyl pyrenediboronates are essential in synthesizing multi-functionalized pyrenes, and the results indicate that the Stille coupling reaction is more effective than the Sonogashira coupling reaction in forming these boronate compounds in good yields. Furthermore, the experimental and theoretical investigations into the photophysical and electrochemical properties of the obtained 1,2,3,6,7,8-multifunctionalized pyrenes show that the phenylethynyl groups at 2,7-positions further increase the system conjugation, which is significant in developing new materials with enhanced properties. Regioselectively multi-functionalized pyrenes were synthesized through one-pot reactions, with Stille and Suzuki coupling reactions involved in the sequence. More importantly, the 1,2,3,6,7,8-hexaphenylethynylpyrene was first obtained through this strategy.image