ONE-ELECTRON REDUCTION OF THE IRON CARBENE COMPLEXES [FE(CP-ASTERISK)(CO)2(=C(OME)R)]+ (R = H OR ME) AND HYDROGEN-ATOM VS ALKYL-RADICAL TRANSFER IN THE 19-ELECTRON INTERMEDIATES

The one-electron reduction of the carbene complexes [Fe(Cp*)(CO)2(=C(OMe)R)][X] (2, R = Me; 4, R = H) affords the 19-electron intermediate [Fe(Cp*)(CO)2(=C(OMe)R)]. which loses the methyl group from the methoxy fragment or abstracts a hydrogen atom from the medium. In the case of R = H, the iron formyl intermediate decomposes in situ into the metal hydride [Fe(CP*)(CO)2H] (9) which acts as a good hydrogen-atom source.