Dearomatization of 2,3-Disubstituted Indoles via 1,8-Addition of Propargylic (Aza)- para-Quinone Methides

J Org Chem. 2021 Dec 3;86(23):16518-16534. doi: 10.1021/acs.joc.1c01857. Epub 2021 Oct 29.

Abstract

Dearomatization of indole is a useful strategy to access indolimines: a motif widely exists in biologically active molecules and natural products. Herein, an efficient method for the dearomatization of 2,3-disubstituted indoles to generate diverse indolimines with tetrasubstituted allenes is described. This work accomplishes dearomatization of 2,3-disubstituted indoles through 1,8-addition of (aza)-para-quinone methides, which are generated in situ from propargylic alcohols. A series of synthetically useful indolimines containing quaternary carbon centers and tetrasubstituted allenes can be accessed in good yields (up to 99%). Additionally, the separability of product isomers, diversified product transformations, and easy scale-up of the reaction demonstrate the potential application of this method.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Indolequinones*
  • Indoles*

Substances

  • Indolequinones
  • Indoles
  • quinone methide