Iterative tandem catalysis: A novel tool for the synthesis of chiral polymers

POLY 394

Anja R. A. Palmans,, Bart A. C. Van As,, Jeroen van Buijtenen,, Lars van der Mee,, and E. W. Meijer, Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, Eindhoven, 5600 MB, Netherlands
The effect of a transoid or cisoid ester conformation in lactones has a pronounced effect on their reactivity in Novozym 435 catalyzed ROP. Moreover, the selectivity of Novozym 435 is also related to the conformation of the ester: cisoid lactones show S-selectivity while transoid lactones show a pronounced R-selectivity. The inability of Novozym 435 to polymerize 6-MeCL stems from its opposing selectivities for the alcohol and acyl-moiety. By combining Novozym 435 with a proper racemization catalyst, inactive alcohol chain ends in the S-configuration can be turned into active alcohol chain end of an R-configuration which can propagate. This combination of 2 different catalysts that work together to accomplish propagation, also referred to as iterative tandem catalysis, is the first example in which a racemic monomer can be completely turned into a homochiral polymer.

Biocatalysis in Polymer Science
1:30 PM-4:45 PM, Tuesday, 12 September 2006 San Francisco Marriott -- Salon 12/13, Oral

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006