Tsai C.-H, Chirdon DN, Maurer AB, Bernhard S, Noonan KJ. T * Carnegie Mellon University, Pittsburgh, USA
Synthesis of Thiophene 1,1-Dioxides and Tuning Their Optoelectronic Properties.
Org. Lett. 2013;
15: 5230-5233
Key words
tin - palladium - thiophene dioxides
Significance
The authors disclose the palladium-catalyzed diarylation of distannylated thiophene 1,1-dioxide (electron-poor aryl coupling partners) and diiodo thiophene 1,1-dioxide (electron-rich aryl coupling partners) by Stille cross-coupling reactions to synthesize various 2,5-bis(aryl)thiophene 1,1-dioxides in moderate yields. Furthermore, the electrochemical and photophysical properties of these diarylated thiophene dioxides were investigated using cyclic voltammetry and fluorescence spectroscopy.
Comment
The corresponding distannylated thiophene 1,1-dioxides are obtained by treatment of 2,5-bis(trimethylsilyl)thiophene 1,1-dioxide with tetrabutylammonium fluoride (TBAF) and bis(tributyltin) oxide. A wide range of these diarylated thiophene dioxides show significant quantum yields, and their appropriate reduction and oxidation potentials may easily be tuned by the use of electron-donating and -withdrawing aryl groups.
