Synthesis of tricarbonyliron cyclohexa-2,4-dienone complexes from tosylhydrazones of acyclic dienone complexes. A novel ansa dicarbonyliron complex by intramolecular trapping of reaction intermediates of the cyclocarbonylation reaction
tricarbonyliron are obtained when tosylhydrazones of tricarbonyliron complexed dienones are submitted to the conditions of the Bamford-Stevens reaction (thermolysis in the presence of strong bases). This cyclocarbonylation reaction proceeds most likely via α-diazodiene complexes, and from there via carbenes, which react intramolecularly with a CO ligand, the coordinatively unsaturated iron species so formed