NICKEL-CATALYZED SUZUKI–MIYAURA CROSSCOUPLING REACTIONS: ONE-POT SYNTHESIS OF 2- ARYLTHIOPHENES

The use of deep eutectic solvents (DESs) that act as an all‐in‐one solvent–template–reactant systems offers an interesting green alternative to conventional syntheses in chemical science. A highly efficient and ligand-free approach for the Suzuki–Miyaura cross-coupling reaction (SMR) of aryl halides with arylboronic acid under the catalysis of Ni(cod)2/K2CO3 in DES has been developed. Under the described green conditions, a category of bromothiophene, whether electron-rich or electron-deficient, was coupled with arylboronic acid to give the excellent yields of biaryls. The structures of the synthesized scaffolds were characterized by IR, NMR, and mass spectral analysis. DES and catalyst can be recovered and reused in this system. This widely used powerful method provides a practical synthetic route for the direct formation of carbon-carbon bonds, which has found considerable academic and industrial use for the production of polymers, fine chemicals and materials, in addition to total synthesis and pharmaceuticals.