Construction of Heterobiaryl Skeletons through Pd-Catalyzed Cross-Coupling of Nitroarenes and Heterocyclic Arylborononate Esters with a Sterically Demanding NHC Ligand.

The palladium-catalyzed Suzuki-Miyaura cross-couplings of nitroarenes and heteroarylboronate esters has been developed. A number of heterobiaryl compounds containing pyridine, pyrimidine, quinoline, furan, thiophene, and pyrazole were prepared using [Pd(cinnamyl)Cl] 2 /2-aryl-5-(2,4,6-triisopropylphenyl)-2,3-imidazolylidene[1,5- a ]pyridines as the catalysts in good to excellent yields. The synthetic practicality of this approach is demonstrated through the synthesis of druglike molecules.