1315477-45-2Relevant academic research and scientific papers
Gold-catalyzed cycloisomerizations of 1-(2-(Tosylamino)phenyl)prop-2-yn-1- ols to 1H-Indole-2-carbaldehydes and (E)-2-(Iodomethylene)Indolin-3-ols
Kothandaraman, Prasath,Mothe, Srinivasa Reddy,Toh, Sharon Si Min,Chan, Philip Wai Hong
, p. 7633 - 7640 (2011)
A method to prepare lH-indole-2-carbaldehydes and (E)-2-(iodomethylene) indolin-3-ols by gold(I)-catalyzed cycloisomerization of l-(2-(tosylamino) phenyl)prop-2-yn-1-ols with N-iodosuccinimide (NIS) is reported. The reactions were shown to be operationally simplistic and proceed efficiently for a wide variety of substrates, affording the corresponding products in good to excellent yields (70-99%). The mechanism is suggested to involve activation of the alkyne moiety of the substrate by the gold(I) catalyst. This triggers intramolecular addition of the tethered aniline moiety to give a vinyl gold intermediate, which undergoes iododeauration with NIS to give the (E)-2-(iodomethylene)indolin-3-ol adduct. Subsequent 1,3-allylic alcohol isomerization (1,3-AAI) followed by formylation of this vinyl iodide intermediate then gives the 1H-indole-2-carbaldehyde.
