Direct Access to Bridged Tetrahydroquinolines and Chromanes via an InCl3-Catalyzed Sequential Three-Component Cascade

J Org Chem. 2020 Jun 19;85(12):8062-8073. doi: 10.1021/acs.joc.0c00893. Epub 2020 Jun 3.

Abstract

A sequential three-component cascade process was developed for the synthesis of bridged tetrahydroquinolines and chromanes bearing 2,6-methanobenzo[d][1,3]diazocine and 2,6-methanobenzo[g][1,3]oxazocine scaffolds, respectively, in good yields from readily available materials. The InCl3-catalyzed reaction progressed via enamine formation, Michael addition, intramolecular cyclization, and intramolecular iminium ion cyclization steps. Notably, this high atom economic approach (-2H2O) allowed the generation of four new bonds (1 C-C and 3 C-N or 1 C-C, 1 C-O and 2 C-N) and two heterocyclic rings in a single operation.

Publication types

  • Research Support, Non-U.S. Gov't