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(Lʹ)N"I; Ln(Lʹ)N"2 is isolated after attempted reduction (Lʹ=t-BuNCH2CH2[C{NC(SiMe3)CHNt-Bu}]) which allows a comparison of the structurally characterised complexes Nd(L)N"2, [Nd(Lʹ)N"I]2, and Nd(Lʹ)N"2.