REACTIONS OF HETEROCYCLIC ORGANOTELLURIUM COMPOUNDS WITH TRIIRON DODECACARBONYL - REACTIONS OF THIOPHENES REVISITED

The reaction of thiophene and of benzothiophene with [Fe-3(CO)(12)] wa s greatly accelerated by microwave heating when carried out in the pre sence of Fe3O4. Thus the same yields of products are obtained in 50 mi n as are achieved in 15-18 h of conventional heating; however no desul furisation of the benzothiophene ring was observed. By contrast, both tellurophene and, more importantly, dibenzotellurophene undergo detell uration reactions with [Fe-3(CO)(12)], the latter reaction affording a dibenzoferrole C18H8Fe2O6, the structure of which has been determined . The reaction of 2-telluraindane with [Fe-3(CO)(12)] gave a complex C 19H16FeO3 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.