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

POLY 394

Anja R. A. Palmans, a.palmans@tue.nl, Bart A. C. Van As, b.v.as@tue.nl, Jeroen van Buijtenen, j.v.buijtenen@tue.nl, Lars van der Mee, L.v.d.Mee@tue.nl, and E. W. Meijer, e.w.meijer@tue.nl. 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