Stereoselective Dynamic Cyclization of Allylic Azides: Synthesis of Tetralins, Chromanes, and Tetrahydroquinolines

J Am Chem Soc. 2018 Jan 31;140(4):1211-1214. doi: 10.1021/jacs.7b11299. Epub 2018 Jan 10.

Abstract

This report describes the stereoselective synthesis of 3-azido-tetralins, -chromanes, and -tetrahydroquinolines via a tandem allylic azide rearrangement/Friedel-Crafts alkylation. Exposure of allylic azides with a pendant trichloroacetimidate to catalytic quantities of AgSbF6 proved optimal for this transformation. This cascade successfully differentiates the equilibrating azide isomers, providing products in excellent yield and selectivity (>25 examples, up to 94% yield and >25:1 dr). In many cases, the reactive isomer is only a trace fraction of the equilibrium mixture, keenly illustrating the dynamic nature of these systems. We demonstrate the utility of this process via a synthesis of hasubanan.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allyl Compounds / chemistry*
  • Azides / chemistry*
  • Chromans / chemical synthesis*
  • Chromans / chemistry
  • Cyclization
  • Molecular Structure
  • Quinolines / chemical synthesis*
  • Quinolines / chemistry
  • Stereoisomerism
  • Tetrahydronaphthalenes / chemical synthesis*
  • Tetrahydronaphthalenes / chemistry

Substances

  • Allyl Compounds
  • Azides
  • Chromans
  • Quinolines
  • Tetrahydronaphthalenes
  • 1,2,3,4-tetrahydroquinoline