Nickel–palladium-catalyzed hydroamination/cyclization of sulfur-substituted 1,6-diynes with secondary amines

Abstract Hydroamination/cyclizations of sulfur-substituted 1,6-diynes catalyzed by nickel or nickel–palladium in DMSO were examined. Pyrroles 2a – l and furans 5a – i bearing various secondary amines were obtained in high yields. The organosulfanylmethyl group on pyrroles was easily oxidized with ceric ammonium nitrate to produce the pyrrolecarboxaldehyde and corresponding acetal.