Coupling of an N-Heterocyclic Garbene on Iron with Alkynes to Form η~5-Cyclopentadienyl-Diimine Ligands

摘要

A cyclometalated N-heterocyclic carbene ligand in a half-sandwich iron complex was found to couple with alkynes, leading to a unique type of ring opening of the carbene ligand and the formation of ferrocenyl-diimine complexes. An intermediary iron complex obtained from the reaction with phenylacetylene reveals that the ring opening follows the formation of a fused heterocycle consisting of an imidazole ring and two alkynes.