Emulsion polymerization was examined as a novel route for the synthesis of core/shell superparamagnetic nanoparticles consisting of a highly crystalline gamma-Fe2O3 core and a very thin polymeric shell wall. These nanoparticles were used as soluble supports for immobilizing Pd catalysts to promote Suzuki cross-coupling reactions. Recovery of catalysts was facilely achieved by applying a permanent magnet externally. Isolated catalysts were reused for new rounds of reactions without significant loss of their catalytic activity.

Candida rugosa lipase immobilized on maghemite nanoparticles demonstrated high stereoselectivity in kinetic resolution of racemic carboxylates and improved long-term stability over its parent free enzyme, allowing the supported enzyme to be repeatedly used for a series of chiral resolution reactions.

Polyphenyl derivatives Q 0700Superparamagnetic Nanoparticle-Supported Catalysis of Suzuki Cross-Coupling Reactions. -Core/shell supermagnetic nanoparticles consisting of a highly crystalline γ-Fe2O3 core and a very thin polymeric shell wall are used as soluble supports for immobilizing palladium-methylimidazolylidene complexes. These catalysts are successfully used for Suzuki coupling reactions and recovered using an external permanent magnet. -(STEVENS, P. D.; FAN, J.; GARDIMALLA, H. M. R.; YEN, M.; GAO*, Y.; Org.

2006Halogenated carboxylic acids and esters P 0260 Superparamagnetic Nanoparticle-Supported Enzymatic Resolution of Racemic Carboxylates. -Candida rugosa immobilized on maghemite nanoparticles, cf. conditions A), demonstrates high stereoselectivity in kinetic resolution of racemic carboxylates (I) and improved long-term stability over its parent free enzyme. Thus, the supported enzyme can be used for a series of resolution reactions. -(GARDIMALLA, H. M. R.; MANDAL, D.; STEVENS, P. D.; YEN, M.; GAO*, Y.; Chem. Commun. (Cambridge) 2005, 35, 4432-4434; Dep. Chem. Biochem., South. Ill. Univ., Carbondale, IL 62901, USA; Eng.) -M. Paetzel 03-071