A method has been developed for the synthesis of 1-arylimidazoles lacking a substituent at position 2, featuring the preparation of 1-arylimidazole N-oxides stabilized as boron trifluoride derivatives, with subsequent reduction to the desired imidazoles. This method permits broad variation of the substituents in the aryl part of these molecules.
Easily accessible and handled ether-imidazolium chlorides were developed as ligand precursors. The coupling reactions of heteroaryl chlorides with aryl/heteroarylboronic acids and esters were catalyzed by the palladium/ether-imidazolium chloride system with high substrate tolerance to give various heterobiaryls in good to excellent yields.