Ultrafast organocatalytic ring‐opening polymerization of N‐sulfonyl aziridine in the melt

Abstract

AbstractAn ultrafast approach for controlled synthesis of well‐defined polysulfonamides is established through organocatalytic anionic ring‐opening polymerization (ROP) of N‐sulfonyl aziridine in the melt. Several different organobases are investigated, and it is found that N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) catalyzed ROP of 2‐methyl‐N‐tosylaziridine (TsMAz) gives the desired polymer, while 1,4‐diazabicyclo[2.2.2]octane (DABCO) and 1,8‐diazabicyclo[5.4.0]‐undec‐7‐ene (DBU) initiate the polymerization along with initiator to produce uncontrolled polymers. Using PMDETA as the catalyst, poly(2‐methyl‐N‐tosylaziridine) with molecular weight over 100 kg/mol can be synthesized in less than 90 s. Various initiators, including carboxylic acid, N‐sulfonyl amide, unactivated amine, phenol, and thiol, are applicable for this protocol to give the molecular weight and end‐group controlled polymers under the open‐flask condition. Combining this ultrafast ROP with ring‐opening metathesis polymerization (ROMP), a brush copolymer is facile synthesized. This approach allows the ultrafast metal‐free synthesis of polysulfonamide and expands the scope of initiators for the ROP of N‐sulfonyl aziridines.