Regioselective C-H activation of lanthanide-bound N-heterocyclic carbenes

The reaction of Ln(L)N'2 (Ln = Nd, Ce; L = t-BuNCH2CH2[C{NCHCHNt-Bu}], N' = N(SiMe3)2) with trimethylsilyl iodide regiospecifically functionalises the carbene backbone at the C4-carbene ring position to afford the silylated complex Ln(L')N'I; Ln(L')N'2 is isolated after attempted reduction (L' = t-BuNCH2CH2[C{NC(SiMe3)CHNt-Bu}]) which allows a comparison of the structurally characterised complexes Nd(L)N'2, [Nd(L')N'I]2, and Nd(L')N'2.