Activation of C-H bonds by rare-earth metallocene-butyl complexes.

The stable metallocene-butyl complexes [(Cp-Me)(2)M(Bu-n)](2) (M = Y, Dy) were synthesized and their reactivity towards to ferrocene and bulky N-heterocyclic carbenes investigated. Selective mono-deprotonation of ferrocene and a benzylic methyl group of IMes were observed, whereas a control reaction of (Cp-Me)(3)M with IMes resulted in a normal-to-abnormal NHC rearrangement.