Synthesis Of Cyclo-Pmma Via Click Chemistry Combined With Atrf

An efficient route to macrocyclic polymers via "click" cyclization was presented. The a-bromine and omega-alkyne PMMA were prepared using the standard ATRP technique, initiated with propargyl. 2-b.romoisobutyrate, Cu (I) Br and N, N, N', N", Nw-pentamethyldiethylenetriamine ( PMDETA). Azidation of the terminal bromine was followed in DMF with sodium azide, and alpha-azide, omega-alkyne PMMA precursor was obtained. Then the "click" cylcization of precursor between terminal azide and alkyne was carried out under the catalysis of CuBr/PMDETA, during the course of the reaction, a pseudo-high dilution technique was utilized to ensure the favored intramolecular cylcization. The nearly complete cylcization has been confirmed by a combination of IR, H-1 NMR and GPC analysis, and cyclo-PMMA with an M-n of 15000, PDI of 1.38 was obtained.