Functional Polyisobutylenes via a Click Chemistry Approach
Polymers and High Performance Materials
1-(omega-Azidoalkyl)pyrrolyl-terminated polyisobutylene (PIB) was successfully synthesized both by substitution of the terminal halide of 1-(omega-haloalkyl)pyrrolyl-terminated PIB with sodium azide and by in situ quenching of quasiliving PIB with a 1-(omega-azidoalkyl)pyrrole Azide substitution of the terminal halide was carried out in 50/50 heptane/DMF at 90 degrees C for 24 h using excess azide The 1-(omega-haloalkyl)pyrrolyl-PIB precursors included 1-(2-chloroethyl)pyrrolyl-PIB, 1-(2-bromoethyl)pyrrolyl-PIB, and 1-(3-bromopropyl)pyrrolyl-PIB. In situ quenching involved direct addition of 1-(2-azidoethyl)pyrrole to quasiliving PIB initiated from 5-tert-butyl-1,3-di(1-chloro-1-methylethyl)benzene (bDCC)/TiCl(4) at -70 degrees C in hexane/CH(3)Cl (60/40, v/v). (1)H NMR analysis of the quenched product revealed mixed isomeric end groups in which PIB was attached at either C(2) or C(3) of the pyrrole ring (C(2)/C(3) = 0 40/0 60) SEC indicated the absence of coupled PIB under optimized conditions, confirming exclusive mono-substitution on each pyrrole ring 1-(3-Azidopropyl)pyrrolyl-PIB was reacted in modular fashion with various functional alkynes, propargyl alcohol, propargyl acrylate, glycidyl propargyl ether, and 3-dimethylamino-1-propyne, via a Huisgen 1,3-dipolar cycloaddition (Click) reaction, using Cu(I)Br/N,N,N',N '',N ''-pentamethyldiethylenetriamine or bromtris(triphenylphosphine)Cu(I) as catalyst The reactions were quantitative and produced PIBs bearing terminal hydroxyl, acrylate, glycidyl, or dimethylaminomethyl groups attached via exclusively four-substituted triazole linkages (C) 2010 Wiley Periodicals, Inc J Polym Sci Part A Polym Chem 48 25332545, 2010
Journal of Polymer Science Part A-Polymer Chemistry
Magenau, A. J.,
Storey, R. F.
(2010). Functional Polyisobutylenes via a Click Chemistry Approach. Journal of Polymer Science Part A-Polymer Chemistry, 48(12), 2533-2545.
Available at: http://aquila.usm.edu/fac_pubs/979