title: Multi-Functionalization of Polymers by Strain-Promoted Cycloadditions.
abstract: We report here a synthetic route to oxime, azide and nitrone-bearing copolymersviareversible 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 post-functionalization of the polymers.In situoxidation 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 twenty 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 bi-functionalization approach made it possible to prepare in a controlled manner multi-functional polymers that could self-assemble into well-defined nanostructures.
authors: Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602.
authors: Petr A
authors: PA
authors: Ledin
authors: Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602.
authors: Nagesh
authors: N
authors: Kolishetti
authors: Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602.
authors: Geert-Jan
authors: GJ
authors: Boons
keywords: SPAAC; SPANC; SPANOC; click chemistry; grafting