Magnetic nanoparticles as an orthogonal support of polymer resins: applications to solid-phase suzuki cross-coupling reactions.
[reaction: see text] Most of the reactants immobilized on conventional solid-phase resins are buried inside the interiors of lightly cross-linked polystyrene beads. An orthogonal support of solid-phase resins needs to be small enough to penetrate the interpolymeric chain spaces of a swollen resin to reach reaction sites. In this paper, we report the use of magnetic nanoparticles ( approximately 4 nm) as an orthogonal matrix to assist solid-phase reactions. A magnetic nanoparticle-supported homogeneous Pd catalyst was employed for promoting the Suzuki cross-coupling of an aryl halide on resins and an excessive arylboronic acid in solution. The workup separating three components (the catalyst, product, and remaining arylborate) is a chromatography-free process. The Pd catalyst was magnetically isolated and recycled from the reaction mixture by applying an external magnetic field. Then, a filtration process was followed to recover the excess borate reagent from the resins/product. Our work here presents the first example of an orthogonal matrix of solid-phase resins and shows the promise of employing nanomaterials in organic synthesis.
Zheng
Yan
Y
Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901-4409, USA.
Stevens
Philip D
PD
Gao
Yong
Y
D001881:Borates / Q000737:chemistry*; D007202:Indicators and Reagents; D007700:Kinetics; D008280:Magnetics; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D012117:Resins, Synthetic / Q000138:chemical synthesis*
D001881:Borates; D007202:Indicators and Reagents; D012117:Resins, Synthetic