Lanthanide Complexes of the Monovacant Dawson Polyoxotungstate [α₁‐P₂W₁₇O₆₁]¹⁰⁻ as Selective and Recoverable Lewis Acid Catalysts

Abstract

Catalytic cornerstone: Lanthanide(III) complexes of a lacunary Dawson-type polyoxometalate catalyze Lewis acid mediated reactions (see figure, TMS=trimethylsilyl). The compounds (NBu4)5H2[α1-Ln(H2O)4P2W17O61] (Ln=Yb, Sm, Eu, La) are much more chemoselective than the lanthanide triflates. Furthermore, the polyoxotungstic framework can play a role, presumably through H-bonding to the substrates.