Isohexide Dinitriles: A Versatile Family of Renewable Platform Chemicals

ChemSusChem. 2017 Aug 24;10(16):3202-3211. doi: 10.1002/cssc.201700617. Epub 2017 Jul 12.

Abstract

Building blocks of isohexides extended by one carbon atom at the 2- or 5-positions are now synthetically accessible by a convenient, selective, base-catalyzed epimerization of the corresponding dinitriles. Kinetic experiments using the strong organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) show that all three possible isohexide dinitrile isomers exist within a dynamic equilibrium. An epimerization mechanism based on density functional theory (DFT) calculations is proposed. Structural identification of all three possible isomers is based on NMR analysis and single crystal x-ray crystallography. DFT calculations confirm that the observed crystal structures are indeed the lowest energy conformers of these isohexide derivatives.

Keywords: biomass; crystal structures; epimers; isohexides; oxygen heterocycles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bridged Bicyclo Compounds, Heterocyclic / chemistry
  • Catalysis
  • Green Chemistry Technology
  • Kinetics
  • Models, Molecular
  • Molecular Conformation
  • Nitriles / chemistry*
  • Quantum Theory
  • Stereoisomerism

Substances

  • Bridged Bicyclo Compounds, Heterocyclic
  • Nitriles