1-(2'-Anilinyl)prop-2-yn-1-ol rearrangement for oxindole synthesis.

A synthetic method that relies on NIS (N-iodosuccinimide)- mediated cycloisomerization reactions of 1-(2'-anilinyl)prop-2-yn-1-ols to gem- 3-(diiodomethyl)indolin-2-ones and 2- (iodomethylene)indolin-3-ones has been developed. The reactions were shown to be chemoselective, with sec- ondary and tertiary alcoholic substrates exclusively giving the 3- and 2-oxindole products, respectively. In the case of the latter, the transformation features an unprecedented double 1,2-OH and 1,2-alkyl migration relay. Density func- tional theory (DFT) calculations based on proposed iodoaminocyclization spe- cies provide insight into this unique di- vergence in product selectivity.