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.