Stickstoffhaltige Dieisen‐hexacarbonyl‐Komplexe aus 3‐Phenyl‐2<i>H</i>‐azirinen

Abstract

Nitrogen‐containing diiron‐hexacarbonyl complexes from 3‐phenyl‐2 H ‐azirines Reaction of 2,2‐dimethyl‐3‐phenyl‐2H‐azirine ( 1 ) with diiron‐enneacarbonyl yields as an insertion product, and in addition to other products, the diiron‐hexacarbonyl complex 2 (Scheme 1), whose structure was derived from spectral data, in particular 13 C‐NMR.‐data (Table 1). With trimethylamine oxide in benzene, 2 is converted into the urea derivative 3 , and yields with cerium (IV) ammonium nitrate the nitrate 4 (Scheme 1). The analogous complexes 6 and 9 have been obtained by irradiation of 1‐phenyl‐vinyl azide ( 5 ) and ironpentacarbonyl (Scheme 1) and from vinyl isocyanate ( 8 ) and diiron‐enneacarbonyl at 40° (Scheme 2), respectively. The azirine 1 , an acetylenic compound and diiron‐enneacarbonyl in benzene react to give complexes of type 10 as the main product (Scheme 3). The structure of complex 10 has been established by X‐ray single crystals analysis. On the 13 C‐NMR. time scale the carbonyl groups of compound 10 show a fluxional behaviour: below −50° the CO‐groups of one of the two Fe(CO) 3 ‐groups undergo intranuclear exchange, above −50° the CO‐groups of both Fe(CO) 3 ‐groups undergo intranuclear exchange. Tentative reaction mechanisms for the formation of the complexes of type 2 and 10 are formulated in Schemes 5, 6 and 7.