Synthesis and derivatisation of ceric tris(tert-butoxy)siloxides.

Metathesis reactions involving cerium(iv) complexes are generally hampered by a high tendency for reduction to the favoured trivalent state and a preference for ligand redistribution. Heteroleptic ceric Ce[OSi(OtBu)3 ]3 Cl(thf) is easily obtained from the oxidation of Ce[OSi(OtBu)3 ]3 (thf)2 with trityl chloride, while the absence of thf triggers formation of homoleptic Ce[OSi(OtBu)3 ]4 . Ce[OSi(OtBu)3 ]3 Cl(thf) engages in salt metathesis reactions with the alkali metal alkoxides KOCH3 and KOtBu, forming Ce[OSi(OtBu)3 ]3 (OR)(thf)x , but experiences an extensive reductive ligand redistribution with the methylating agent ZnMe2 .