Multifunctionalization of Polymers by Strain-Promoted Cycloadditions

作者：Ledin Petr A; Kolishetti Nagesh; Boons Geert Jan^*

来源：Macromolecules, 2013, 46(19): 7759-7768.

DOI：10.1021/ma400913a

We report here a synthetic route to oxime, azide, and nitrone-bearing copolymers via reversible addition fragmentation chain transfer copolymerization of 4-vinylbenzaldehyde and 1-(chloromethyl)-4-vinylbenzene with styrene. The azide and nitrone moieties could be employed in strain-promoted 1,3-dipolar cycloadditions with various functionalized dibenzocyclooctynols (DIBO) for metal-free postfunctionalization of the polymers. In situ oxidation of the oximes with hypervalent iodine gave nitrile oxides, which could also be employed as 1,3-dipoles for facile cycloadditions with DIBO derivatives. Kinetic measurements demonstrated that the pendant nitrile oxides reacted approximately 20 times faster compared to similar cycloadditions with azides. A block copolymer, containing azide and oxime groups in segregated blocks, served as a scaffold for attachment of hydrophobic and hydrophilic moieties by sequential strain-promoted alkyne azide and strain-promoted alkyne nitrile oxide cycloadditions. This sequential bifunctionalization approach made it possible to prepare in a controlled manner multifunctional polymers that could self-assemble into well-defined nanostructures.

• 出版日期2013-10-8