CH Activation of Acetonitrile by Alkyl Compounds of the Early Lanthanoids: Dimeric Cyanomethyl‐Lanthanoid Complexes with CH2CN Bridges

CH2CN bridging ligands are novel. Treatment of acetonitrile with the alkyl lanthanum or cerium compounds 1 results not in the expected insertion of a nitrile group into the Ln‐C σ bond, but rather in activation of a CH bond in the methyl group, leading to the new type of complex 2. In the case of the dimeric lanthanum complex 2, where n = 2, the product has been shown to contain an eight‐membered ring in a chair conformation (Cp*  C5Me5). equation image