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.
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