Reduction of titanocene dichloride with dysprosium: access to a stable titanocene(ii) equivalent for phosphite-free Takeda carbonyl olefination.

The reduction of titanocene dichloride with dysprosium yields a new titanocene(ii) equivalent without the need for further stabilising ligands. This reagent can be employed in combination with dithioacetals for the olefination of different carbonyl groups and allows for a simplified all-in-one procedure.

A divalent heteroleptic lanthanoid fluoride complex stabilised by the tetraphenylcyclopentadienyl ligand, arising from C-F activation of pentafluorobenzene.

The divalent heteroleptic lanthanoid fluoride complex, [Yb(C5Ph4H)(µ-F)(thf)2]2, as well as [Yb(C5Ph4H)2(thf)] and [Yb(C5Ph4H)(C6F5)(thf)2] were obtained from reactions of ytterbium metal with Hg(C6F5)2 and tetraphenylcyclopentadiene under different conditions, and C-F activation of C6F5H by Yb metal was observed.