An Atom-Economical Approach to 2-Aryloxypyridines and 2,2′/2,3′-Diaryloxybipyridines via Ruthenium-Catalyzed [2+2+2] Cycloadditions

Abstract

An efficient, ruthenium(II)-catalyzed, solvent-free approach for the synthesis of 2-aryloxypyridines with good to excellent yields has been developed by the reaction of 1,6-diynes with aryl cyanates. This atom-economical catalytic strategy offers a mild and practical approach to access a variety of such cycloadducts with excellent regioselectivities. The protocol was further extended to the synthesis of 2,2′- and 2,3′-diaryloxybipyridines by the reaction of tetraynes with aryl cyanates.