Photoreaktionen mit Fulleren‐C60 [3 + 2]‐Photocycloaddition von 2,3‐Diphenyl‐2H‐azirin

Photoreactions with C60‐Fullerene. [3 + 2] Photocycloaddition of 2,3‐Diphenyl‐2H‐azirine Upon irradiation 2,3‐Diphenyl‐2H‐azirine (2) is added to C60 1 with formation of mono and oligo adducts. 1,9‐(3,4‐Dihydro‐2,5‐diphenyl‐2H‐pyrrolo)fulleren‐60 (3) has been isolated and identified by standard spectroscopic methods. Mechanistic studies revealed two reaction paths leading to 3, i.e. the classic 1,3‐dipolar cycloaddition via the nitrile ylide 4 (direct irradiation) or a route via 2‐azaallenyl radical cations 5 (sensitization by photoinduced electron transfer).