Ag(i)-Catalyzed one-pot synthesis of 4-fluorobenzo[b][1,6] naphthyridines and 4-fluoroisoquinolines via iminofluorination of alkynes with Selectfluor

Abstract

Ag(I)-Catalyzed one-pot synthesis of 4-fluorobenzo[b][1,6]naphthyridines is described from o-alkynylquinolinyl aldehydes through imines in good to excellent yields. Selectfluor is used as a fluorinating reagent and the reaction proceeded at room temperature in an open atmosphere. Reactions employed in this synthesis method are also applied for the synthesis of 8-fluoro-1,6-naphthyridine, 7-fluoro-pyrazolo[4,3-c]pyridine and 4-fluoroisoquinoline derivatives. Standardized conditions were also applied on a gram scale reaction and gave a good yield of the product.