Reactivity of the tethered alkyl uranium bonds of (η5:κ1-C5Me4SiMe2CH2)2U

Uranium-carbon bond reactivity has been investigated with the bis(tethered silylalkyl) uranium metallocene (η5:κ1-C5Me4SiMe2CH2)2U, 1. Tert-butyl nitrile, tBuCN, inserts into both of the tethered U-C bonds to produce the bis(tethered ketimide) complex [η5:κ1-C5Me4SiMe2CH2C(tBu)N]2U, 2, which has unusually bent U-N-C bond angles. Carbon dioxide also inserts into both U-C bonds of 1 yielding the bis(tethered carboxylate) (C5Me4SiMe2CH2CO2)2U, 3. Neither PhCCPh nor PhCCH insert into the U-C bonds, but PhCCH cleaves the silylalkyl tethers in 1 to generate (C5Me4SiMe3)1− ligands in the complex (C5Me4SiMe3)2U(CCPh)2, 4.