Tuesday, September 18, 2012

Side-Chain Modification and Grafting Onto via Olefin Cross-Metathesis

de Espinosa, L. M., Kempe, K., Schubert, U. S., Hoogenboom, R. and Meier, M. A. R. (2012), Side-Chain Modification and Grafting Onto via Olefin Cross-Metathesis. Macromol. Rapid Commun.. doi: 10.1002/marc.201200487
In this paper, Grubbs second generation catalyst is used to "efficiently" functionalize polymer ends. By adding a large excess of acrylate and tuning terminal alkene with acrylate steric bulk, they are able to discourage self-metathesis that leads to cyclic structures in order to gain the desired product with reasonable PDIs. A combination of SEC, FTIR-ATR, and NMR are used to differentiate cross-metathesis and self-metathesis products though with difficulty. SEC shows, in general higher MW shoulders in their traces suggesting that self-metathesis is still occurring, while high conversions of terminal alkenes are seen via NMR. According to the authors, the main advantages of this method are the introduction of various functional groups and the maintenance of double bond functionality (as opposed to thiol-ene chemistry).

No comments:

Post a Comment