Copper-Mediated Formally Dehydrative Biaryl Coupling of Azine N-Oxides and Oxazoles

A copper-mediated formally dehydrative biaryl coupling of azine N-oxides and oxazoles has been developed. The CC bond-forming process proceeds, accompanied by the removal of the oxygen atom from the azine core, to directly afford the azineoxazole biaryl linkage. Moreover, this system requires no noble transition metals such as palladium and rhodium, which are common promotors in the related dehydrogenative couplings with the azine N-oxide. Thus, the present protocol can provide a unique and less expensive approach to the azine-containing biheteroaryls of substantial interest in pharmaceutical and medicinal chemistry.