Coupling Reactions of Heteroarenes with Phosphites under Silver Catalysis

Abstract

A silver-catalyzed dehydrogenative cross-coupling reaction of substituted furans, thiophene, thioazole, and pyrrole <b>1a</b>–<b>e</b> with dialkyl phosphites <b>2</b> was first developed to afford corresponding phosphonated products <b>3a</b>–<b>h</b> with up to 89% yield and good regioselectivities. Moreover, an unprecedented coupling of various substituted pyridines <b>1f</b>–<b>k</b> with dialkyl phosphites <b>2</b> using AgNO₃ as a catalyst and K₂S₂O₈ as an oxidant, followed by reduction with Na₂S₂O₃, was also realized to furnish desired pyridine phosphonates <b>3i</b>–<b>q</b> in satisfactory yields with good regioselectivities