Reactivity and regioselectivity of magnesium phenolates towards isatins: One-step synthesis of 3-(2-hydroxyaryl)-3-hydroxyindolones
摘要:
A variety of aryloxymagnesium bromides react with isatins under extremely mild conditions to provide 3-(2-hydroxyaryl)-3-hydroxyindolones in good yield. The main features of this protocol consist of exceptionally selective ortho-C-alkylation of the ambident phenolate anion and the lack of diarylated products. Moreover, aryloxymagnesium bromides derived from meta-substituted phenols react with isatins exclusively at the sterically less hindered ortho-position of the phenol. (C) 1998 Elsevier Science Ltd. All rights reserved.