Rhodium(III)-Catalyzed Sequential Cyclization of N-Boc Hydrazones with Propargylic Monofluoroalkynes via C-H Activation/C-F Cleavage for the Synthesis of Spiro[cyclobutane-1,9'-indeno[1,2- a]indenes]

J Org Chem. 2022 May 6;87(9):6105-6114. doi: 10.1021/acs.joc.2c00372. Epub 2022 Apr 26.

Abstract

An effective rhodium(III) catalysis for the construction of valuable tetracyclic compounds is described herein. This domino process involving the C-H activation/[3 + 2] annulation/intramolecular Friedel-Crafts reaction sequences of simple and readily available N-Boc hydrazones and propargylic monofluoroalkynes afforded fused tetracyclic spiro[cyclobutane-1,9'-indeno[1,2-a]indenes] in moderate to good yields, featuring three C-C bond formation. Moreover, control experiments indicated that the C-H activation might be involved in the rate-determining step.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization
  • Cyclobutanes*
  • Hydrazones / chemistry
  • Indenes* / chemistry
  • Molecular Structure
  • Rhodium* / chemistry

Substances

  • Cyclobutanes
  • Hydrazones
  • Indenes
  • Rhodium