posted on 2024-01-12, 14:36authored byYun-Long Zhu, Yi-Fan Dong, Si-Ru Wang, You-Gui Li, Xiang Wu, Long-Wu Ye
A gold-catalyzed, nucleophile-controlled
cascade reaction of N-(2-azidophenyl-ynyl)methanesulfonamides
with nitriles
and water is described that provides structurally diverse 5H-pyrimido[5,4-b]indoles and 2-benzylidene-3-indolinones
in good to excellent yields. Mechanistic studies indicate that the
β-sulfonamido-α-imino gold carbene is the key intermediate
which is generated through the gold-catalyzed cyclization of N-(2-azidophenyl-ynyl)methanesulfonamides and undergoes
formal [4 + 2] cascade annulation with nitriles and intramolecular
SN2′ type reaction with water, respectively.