Asymmetric enolization of prochiral cyclic ketones by polymer-supported lithium amides

ORGN 471

Lili Ma, Lili_Ma@Brown.Edu, Chemistry Department, Brown University, Box H, Providence, RI 02912 and Paul G. Williard, Department of Chemistry, Brown University, 324 Brook street, Providence, RI 02912.
Polymer-supported chiral aminoethers and diamines, with or without a spacer, were effectively prepared from amino acid derivatives and Merrifield's resin. Treatment of polymer-supported amines with n-Butyllithium gave the corresponding polymer-suppported chiral lithium amide bases which were tested in the asymmetric enolization reactions of prochiral ketones. The resulted trimethylsilyl enol ethers were obtained in up to 82% ee at room temperature in the absence of additives. The polymer-supported chiral lithium amides can be readily recycled and reused without significant loss of reactivity and selectivity.
 

New Reactions and Methodology, Total Synthesis, Materials, Devices and Switches, Lipids, Nucleotides and Mimetics
8:00 PM-10:00 PM, Tuesday, March 27, 2007 Hyatt Regency Chicago -- Riverside Center, Poster

Division of Organic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007