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

Abstract

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]₃Cl(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]₃Cl(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.