title: The ketimide ligand is not just an inert spectator: heteroallene insertion reactivity of an actinide-ketimide linkage in a thorium carbene amide ketimide complex.
abstract: The ketimide anion R2C=N(-) is an important class of chemically robust ligand that binds strongly to metal ions and is considered ideal for supporting reactive metal fragments due to its inert spectator nature; this contrasts with R2N(-) amides that exhibit a wide range of reactivities. Here, we report the synthesis and characterization of a rare example of an actinide ketimide complex [Th(BIPM(TMS)){N(SiMe3)2}(N=CPh2)] [2, BIPM(TMS)=C(PPh2NSiMe3)2]. Complex 2 contains Th=C(carbene), Th-N(amide) and Th-N(ketimide) linkages, thereby presenting the opportunity to probe the preferential reactivity of these linkages. Importantly, reactivity studies of 2 with unsaturated substrates shows that insertion reactions occur preferentially at the Th-N(ketimide) bond rather than at the Th=C(carbene) or Th-N(amide) bonds. This overturns the established view that metal-ketimide linkages are purely inert spectators.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (UK).
authors.forename: Erli
authors.initials: E
authors.lastname: Lu
authors.forename: William
authors.initials: W
authors.lastname: Lewis
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Blake
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Liddle
keywords: N ligands; amides; carbenes; ketimides; thorium