Cationic Au(I)-catalyzed cycloisomerization of N-(2-alkynylphenyl)indolines for the construction of indolobenzazepine skeleton

An intramolecular reaction of N-(2-alkynylphenyl)indolines proceeded efficiently to give indolo[1,7-ab][1]benzazepine derivatives in high to excellent yields by cationic Au(I)-catalyzed 7-endo-dig selective cycloisomerization along with DDQ oxidation. The present transformation could be used for the intramolecular reaction of N-(2-alkynylphenyl)-1,2,3,4-tetrahydroquinoline and N-(2-alkynylphenyl)-N-methylaniline, and construction of a dibenzazepine skeleton was achieved.