Reactions of Oxygen with Metallaheterocyclic Alkyl Amide Complexes. Selective Insertion of Oxygen into Metal−Carbon Bonds

Reactions of O2 with the four-membered cyclic complexes {(Me2N)[(Me3Si)2N]M[N(SiMe3)SiMe2CH2]}2 (M = Zr (1a), Hf (1b)), containing both M−C and M−N bonds, give the five-membered cyclic complexes {(Me2N)[(Me3Si)2N]M[N(SiMe3)SiMe2CH2O]}2 (M = Zr (2a), Hf (2b)) with rarely observed selective O insertion into the M−C bonds. Both dimeric products exist as interesting cis and trans isomers.