3-Nitroindoles Serving as <i>N</i>-Centered Nucleophiles for Aza-1,6-Michael Addition to <i>para</i>-Quinone Methides

Abstract

An unprecedented N-alkylation of 3-nitroindoles with para-quinone methides was developed for the first time. Using potassium carbonate as the base, a wide range of structurally diverse N-diarylmethylindole derivatives were obtained with moderated to good yields via the protection group migration/aza-1,6-Michael addition sequences. The reaction process was also demonstrated by control experiments. Different from the previous advances where 3-nitrodoles served as electrophiles trapping by various nucleophiles, the reaction herein is featured that 3-nitrodoles is defined with latent N-centered nucleophiles to react with ortho-hydrophenyl p-QMs for construction of various N-diarylmethylindoles.

Keywords

• 3-nitroindoles
• <i>N</i>-alkylation
• <i>para</i>-quinone methides
• <i>aza</i>-1,6-Michael addition
• indole derivatives