One‐pot tandem ring‐opening polymerization of N‐sulfonyl aziridines and “click” chemistry to produce well‐defined star‐shaped polyaziridines

Abstract

AbstractAn effective approach for fast synthesis of well‐defined star‐shaped poly(2‐methyl‐N‐tosylaziridine)s was developed by one‐pot tandem ring‐opening polymerization (ROP) of N‐sulfonyl aziridines with trimethylsilyl azide (TMSN3) and “click” reaction with alkynes. Azido terminated polyaziridines (α‐N3‐PAzs) could be achieved via ROP of N‐sulfonyl aziridines with TMSN3 in the presence of organic superbases. The catalytic efficiency of organobases, including 1,4‐diazabicyclo[2.2.2]octane (DABCO), 1,8‐diazabicyclo[5.4.0]‐7‐undecene (DBU), 7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (MTBD), 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD), and N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA), was evaluated, and all of them except TBD afforded “living”/controlled ROP of 2‐methyl‐N‐tosylaziridines (TsMAz). Star‐shaped polyaziridines were then fastly synthesized by the one‐pot tandem strategy. During the reaction process, PMDETA catalyzed ROP first, then was triggered to be a ligand by adding CuBr for “click” reaction. Well‐defined 3‐ and 4‐arm star P(TsMAz)s were successfully prepared, and subsequently desulfonylated to give star‐shaped polypropylenimines (PPIs). PPI stars exhibited intrinsic photoluminescence properties from the polyamine arms.