title: Application of microgels as polymer supports for organic synthesis: preparation of a small phthalide library, a scavenger, and a borohydride reagent.
abstract: Microgel polymers containing a series of functional groups have been prepared. These microgels were composed of cross-linked poly(styrene) and were prepared by radical polymerization in solution. The microgel polymers exhibit good solubility in an array of different organic solvents, and in addition, they can be efficiently precipitated by the addition of methanol and isolated by filtration. A nine-member phthalide library was synthesized using an aminomethyl-functionalized microgel 5. To further demonstrate the versatility of these microgel polymers, tris(2-aminoethyl)amino microgel 11 was examined as a scavenger reagent to remove unreacted isocyanate after a urea synthesis. Finally, a microgel-supported ammonium borohydride reagent 14 was successfully prepared and used as a reducing agent. Notable features of these microgels are that in all applications the progress of the reaction could be monitored by standard NMR techniques and their preparation is performed using common glassware and techniques found in all organic laboratories.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Osamu
authors.initials: O
authors.lastname: Shimomura
authors.forename: Bruce
authors.initials: B
authors.lastname: Clapham
authors.forename: Carsten
authors.initials: C
authors.lastname: Spanka
authors.forename: Suresh
authors.initials: S
authors.lastname: Mahajan
authors.forename: Kim D
authors.initials: KD
authors.lastname: Janda
mesh_terms: D001572:Benzofurans / Q000138:chemical synthesis*; D001894:Borohydrides / Q000737:chemistry*; D002625:Chemistry, Organic; D005782:Gels / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D055601:Organic Chemistry Phenomena; D011108:Polymers / Q000737:chemistry*
chemical_list: D001572:Benzofurans; D001894:Borohydrides; D005782:Gels; D007202:Indicators and Reagents; D011108:Polymers; C082022:phthalide