Enantioselective homogeneous catalysts immobilized in chiral ionic liquid phase

ORGN 652

So-Hye Cho, sohyec@scripps.edu1, Claire Schmerberg, c-schmerberg@northwestern.edu2, SonBinh T. Nguyen2, and Joseph T. Hupp, j-hupp@northwestern.edu2. (1) Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, (2) Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113
In recent years, the application of ionic liquids as solvents in catalytic processes has attracted significant attention. However, the number of chiral ionic liquids (CILs) remains limited even though they may serve as chiral reaction media in chiral resolution and enantioselective reactions. Several chiral ionic liquids based on naturally occurring alkaloids (e.g. ephedrine, hydroquinine, etc.) and chiral acids (e.g. tartaric acid, lactic acid, etc.) have been successfully synthesized and used as catalyst-immobilizing matrices. When an enantioselective Mn(Salen)Cl epoxidation catalyst was dissolved in the room-temperature CIL phase, it can be easily separated from organic reactants and products by the addition of diethylether. The Mn(Salen)Cl catalyst also showed enhanced activity in the CIL phase compared to dichloromethane. More interestingly, Co(Salen)X catalysts also show enhanced enantioselectivity in the synthesis of cyclic carbonate from epoxide and CO2 when dissolved in the CIL phase.
 

Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005