Palladium-Catalyzed/Copper-Mediated Decarbonylative Cross-Coupling of S -Pyrimidyl Thioesters for Biaryl Synthesis.

A palladium-catalyzed/copper-mediated cross-coupling of S -pyrimidinyl thioesters with arylboronic acids to yield biaryls is described. The reaction is likely to proceed via cleavage of the S-C(O) bond and subsequent release of CO, rather than via cleavage of the S-C(pyrimidine) bond and release of SCO, as supported by the results of both experimental and computational studies. The investigation of the reaction scope with various S -pyrimidinyl thioesters and arylboronic acids showed that the reaction is significantly affected by the substituent of the thioester and the presence of a chelatable ortho substituent was found to increase reaction efficiency.