2‐Azaallenyl‐Chromkomplexe; Insertion von 1‐Aminopropin in M = C‐ und C = 0‐Bindungen. Intramolekulare Cyclopropanierung sowie [3 + 2]‐Cycloaddition unter Bildung eines 1,3‐Diaminoindens

Organic Syntheses via Transition Metal Complexes, 43. ‐ 2‐Azaallenyl Chromium Complexes; Insertion of 1‐Amino‐propyne into M  C and C  0 Bonds: Intramolecular Cyclopropanation and [3 + 21 Cycloaddition with Formation of a 1,3‐Diaminoindene Organic Synthese via Transition Metal Complexes, 431). ‐ 2‐Azaallenyl Chromium Complexes; Insertion of 1‐Aminopropyne into M = C and C = O Bonds; Intramolecular Cyclopropanation and [3+2]Cycloaddition with Formation of a 1,3‐Diaminoindene The 2‐azaallenyl complex LnM⊖ ‐C(Ph)=N⊕ = C(Ph)OCO‐Ph 3 [LnM = Cr(CO)5] adds to the 1‐aminopropyne Et2N‐C = C‐CH3 (4) to give the aminocarbene complexes LnM=C(NEt2)‐C(CH3)=C(Ph)‐N(COPh)2 [(E)‐5] and LnM=C(NEt2)‐C(CH3)=C(Ph)‐NH(COPh) [(E)‐9] (by insertion of 4 into the M = C bond of 3) as well as a 1,3‐diaminoindene 6 (by [3+2] cycloaddition). An iminocarbene complex LnM = C(Ph) ‐ N=C(Ph) ‐O‐C(Ph) = C(CH3)‐CONEt2 (7) is formed as a further product (by insertion of4 into the C=O bond of 3). The latter type of reaction can also be applied to metal‐free carbonyl compounds: thus phthalic anhydride reacts smoothly with 4 to give a γ‐lactone 12 and a 1,3‐indanedione 13 by insertion of 4 into a C=O and C‐O bond, respectively. The thermolysis of the iminocarbene complex 7 yields a cyclopropane derivative 14 by an intramolecular attack of the carbene carbon at the (O)C=C bond. The structure of 14 has been determined by a crystal structure analysis. On thermolysis of 3 a triphenyloxazole 15 is obtained. The mechanisms of these reactions are discussed.