Facile Syntheses of N-Heterocyclic Carbene Precursors through I2 - or NIS-Promoted Amidiniumation of N-Alkenyl Formamidines

Chem Asian J. 2016 May 6;11(9):1361-5. doi: 10.1002/asia.201600182. Epub 2016 Mar 30.

Abstract

We have developed I2 - or N-iodosuccinimide (NIS)-mediated amidiniumation of N-alkenyl formamidines for the syntheses of cyclic formamidinium salts, some of which could be directly used as N-heterocyclic carbene (NHC) precursors. Treatment of iodine-containing formamidinium salts with Al2 O3 led to the formation of cyclic formamidinium salts with an unsaturated backbone. A rhodium(I) complex ligated by a representative NHC was prepared by the reaction of [Rh(cod)Cl]2 (cod=1,5-cyclooctadiene) with the free carbene obtained in situ from deprotonation of the corresponding formamidinium salts. The NHCs prepared in situ can also react with S8 to afford the corresponding thiones.

Keywords: N-heterocyclic carbenes; N-iodosuccinimide; alkenes; iodine; iodoamination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amidines / chemistry*
  • Heterocyclic Compounds / chemical synthesis*
  • Heterocyclic Compounds / chemistry
  • Iodine / chemistry*
  • Methane / analogs & derivatives*
  • Methane / chemical synthesis
  • Methane / chemistry
  • Molecular Structure
  • Succinimides / chemistry*

Substances

  • Amidines
  • Heterocyclic Compounds
  • Succinimides
  • carbene
  • N-iodosuccinimide
  • formamidine
  • Iodine
  • Methane