Lewis Acid‐Mediated One‐Electron Reduction of Nitrous Oxide

The one‐electron reduction of nitrous oxide (N 2 O) was achieved using strong Lewis acids E(C 6 F 5 ) 3 (E=B or Al) in combination with metallocenes. In the case of B(C 6 F 5 ) 3 , electron transfer to N 2 O required a powerful reducing agent such as Cp* 2 Co (Cp*=pentamethylcyclopentadienyl). In the presence of Al(C 6 F 5 ) 3 , on the other hand, the reactions could be performed with weaker reducing agents such as Cp* 2 Fe or Cp 2 Fe (Cp=cyclopentadienyl). The Lewis acid‐mediated electron transfer from the metallocene to N 2 O resulted in cleavage of the N−O bond, generating N 2 and the oxyl radical anion [OE(C 6 F 5 ) 3 ] ⋅− . The latter is highly reactive and engages in C−H activation reactions. It was possible to trap the radical by addition of the Gomberg dimer, which acts as a source of the trityl radical.