Reactions of heterocyclic organotellurium compounds with triiron dodecacarbonyl: reactions of thiophenes revisited
Abstract
The reaction of thiophene and of benzothiophene with [Fe3(CO)12] was greatly accelerated by microwave heating when carried out in the presence of Fe3O4. Thus the same yields of products are obtained in 50 min as are achieved in 15–18 h of conventional heating; however no desulfurisation of the benzothiophene ring was observed. By contrast, both tellurophene and, more importantly, dibenzotellurophene undergo detelluration reactions with [Fe3(CO)12], the latter reaction affording a dibenzoferrole C18H8Fe2O6, the structure of which has been determined. The reaction of 2-telluraindane with [Fe3(CO)12] gave a complex C19H16FeO3 in which a novel dimer of the detellurated C8H8 fragment is co-ordinated to an Fe(CO)3 unit, as determined crystallographically. The released tellurium was isolated as either FeTe or as [Fe3Te2(CO)9], depending on the reaction conditions.