ChemInform Abstract: Gold-Catalyzed 5-endo-dig Cyclization of 2-[(2-Aminophenyl)ethynyl]phenylamine with Ketones for the Synthesis of Spiroindolone and Indolo[3,2-c]quinolone Scaffolds

A tandem gold-catalyzed 5-endo-dig/spirocyclization of 2-[(2-aminophenyl)ethynyl]phenylamines with isatins was achieved to produce the corresponding 5′,11′-dihydrospiro[indoline-3,6′-indolo[3,2-c]quinolin]-2-one derivatives in good yields with high regioselectivity. This reaction proceeded well at ambient temperature under mild conditions. Ketones also participated smoothly under similar conditions to produce 6,6-disubstituted-6,11-dihydro-5H-indolo[3,2-c]quinolones.