A Magnetically Separable Heterogeneous Deallylation Catalyst: [CpRu(η 3 ‐C 3 H 5 )(2‐pyridinecarboxylato)]PF 6 Complex Supported on a Ferromagnetic Microsize Particle Fe 3 O 4 @SiO 2

The highly reactive and chemoselective homogeneousdeallylation catalyst CpRu(η 3 ‐C 3 H 5 )(4‐substituted‐2‐pyridinecarboxylato) was immobilized on microsize spherical Fe 3 O 4 @SiO 2 particles. The resultant heterogeneous catalyst displays high saturation magnetization, weak coercive forces and high levels of dispersibility. The catalyst has increased the utility of deallylation by allowing the reaction to be conducted without extra additives. The only co‐product of the reaction is a volatile allyl ether compound. Here, we demonstrate the efficient deallylation and separation of highly polar multifunctional compounds as well as multiple rounds of catalyst recycling without significant loss of reactivity. The usefulness of this catalyst has been confirmed by the synthesis of a triribonucleotide 3–5 U. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)