Combining chiral elements in Asymmetric Phase-Transfer Catalysts: Styrene oxide and chiral α, α'-disubstituted pyrroline and piperidine derived structures

ORGN 75

Gregory Grover, grovgr01@gettysburg.edu, Walter E. Kowtoniuk, kowtwa01@gettysburg.edu, and Darren K. MacFarland, dmacfarl@gettysburg.edu. Department of Chemistry, Gettysburg College, 300 North Washington St., Gettysburg, PA 17325
A new asymmetric phase transfer catalyst, designed by combining the chiral styrene oxide with 2,5-dimethylpyrroline and 2,5-dimethylpiperdine, is described. Catalytic testing using standard glycine imino ester alkylations shows good yields and moderate to good enantioselectivities with a surprisingly large shift in enantioselectivity over the course of the reaction. While this effect is not observed for all halides, it is interesting and led us to consider possible mechanisms. Alkylation of the β-hydroxyl group led to catalysts with improved selectivity and a larger change in enantioselectivity during the reaction.

 

Asymmetric Reactions and Syntheses, Physical Organic Chemistry, Combinatorial Chemistry, Total Synthesis
8:00 PM-10:00 PM, Sunday, 26 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster

Division of Organic Chemistry

The 231st ACS National Meeting, Atlanta, GA, March 26-30, 2006