Guillaume Gody, Christian Rossner, John Moraes, Philipp Vana, Thomas Maschmeyer, and Sébastien Perrier Journal of the American Chemical Society Article ASAP
This interesting paper introduces a new method for generating RAFT polymers with isocynate end-functionality that can be further reacted with alcohols or amines to yield a-functionalized polymers. The key to their method is a chain transfer agent (CTA) bearing a carbonyl-azide that rearranges in-situ to form the iso-cynate. The rearrangement is hypothesized to be driven by the fragmentation of the C-S bond during initiation. Interestingly, polymerization seems to be required for successful rearrangement judging by the degradation of the CTA when exposed to initiation conditions when no monomer is present. Their method produced isocynate end-functional polymers with reasonable PDIs as well as efficient coupling products when these polymers were reacted with alcohols and dibutyltin dilaurate as a catalyst. Amines were also coupled, though these reactions were not as efficient. Though this method may not necessarily be a true "click" reaction, it will definitely offer "tantalizing opportunities" to polymer chemists.