The synthesis and characterization of novel N-Heterocyclic carbene iron complexes

Abstract

Novel N-heterocyclic carbene (NHC) complexes containing either a symmetric or an asymmetric (i.e. containing two different N-substituents) donor functionality and a 5- or 6-membered ring as backbone have been synthesized. These complexes have been synthesized by using the direct metallation method with Fe[HMDS]2 and the “free carbene method with LiHMDS. One of these complexes, containing three 5-membered ring NHC’s having a pyridine and a methyl substituent, was stable under ambient conditions, while the other complexes decomposed to an NHC dimer product. All compounds were characterized by ESI-MS. The physical characteristics as well as the catalytic potential of the stable compound can now be determined.