Synthesis of Symmetrical and Unsymmetrical 1,3-Diheteroarylbenzenes Through Palladium-Catalyzed Direct Arylation of Benzene-1,3-disulfonyl Dichloride and 3-Bromobenzenesulfonyl Chlorides

Abstract : The palladium-catalyzed synthesis of unsymmetrical 1,3-diheteroarylbenzenes was investigated. The first synthetic pathway relies on the desymmetrization of benzene-1,3-disulfonyl dichloride through two successive palladium-catalyzed direct desulfitative arylations with two different heteroarenes. The second strategy employs the orthogonal functionalization of 3-bromobenzenesulfonylchloride using an iterative C–H bond arylation sequence, namely, palladium-catalyzed direct desulfitative arylation followed by a palladium-catalyzed direct arylation step using aryl bromide as the coupling partner. The synthesis of symmetrical 1,3-diheteroarylbenzenes was also investigated