4‐Styrenesulfonyl‐(2‐methyl)aziridine: The First Bivalent Aziridine‐Monomer for Anionic and Radical Polymerization

Abstract

4‐Styrenesulfonyl‐(2‐methyl)aziridine (StMAz), the first orthogonal aziridine monomer, for both anionic ring‐opening and radical polymerization is presented. Both polymerization pathways are accessible without using protective groups. Aza‐anionic ring‐opening polymerization (A‐AROP) of StMAz and other methyl‐aziridine derivatives provide multifunctional polyaziridines. Molecular weights between 3000 and 13 000 g mol−1 are obtained with low molecular weight dispersities (Ð = 1.1). The amount of vinyl groups in linear polyaziridines from A‐AROP depends on the monomer/comonomer ratio. The vinyl groups of P(StMAz)‐ homo‐ or copolymers are entirely convertible by thiol‐ene addition. This allows modification with multiple functional groups. Free radical polymerization of StMAz leads to polyalkylenes with aziridine side groups, which are known to be efficiently addressable via nucleophiles. Polysulfonamides still belong to a rather new class of polymers accessible by anionic polymerization. Enlarging the scope of postpolymerization modifications on polyaziridines/‐sulfonamides is important for further macromolecular architectures. The aziridine and the vinyl group are combined to develop the first orthogonal monomer for aza‐anionic polymerization and radical polymerization.

Aziridines and azetidines: building blocks for polyamines by anionic and cationic ring-opening polymerization

“…The olefins were post-modified by a radical thiol-ene reaction with N-acetyl-L-cysteine methyl ester providing quantitative conversion. 133 2-Methyl-N-(4-styrenesulfonyl) aziridine (StMAz) 137 was the first bivalent aziridine derivative to undergo either anionic or radical polymerization (Fig. 6d).…”

Comparison of the Anionic Ring-Opening Polymerizations of N-(Alkylsulfonyl)azetidines

“…This was a significant breakthrough as the resulting polymers could be converted to linear polypropylenimine and thus represented the first example of a living AROP route to polyimines (Scheme B). Since this initial report, Wurm et al, − Taton et al, − Guo et al, Zhang and Wu, and we ourselves , have studied the polymerization of numerous N -sulfonylaziridines and their subsequent deprotection to afford linear polyimines …”

Carboxylic Acid Initiated Organocatalytic Ring-Opening Polymerization of N-Sulfonyl Aziridines: An Easy Access to Well-Controlled Polyaziridine-Based Architectural and Functionalized Polymers

“…In sharp contrast to the ROP of epoxides, lactones, cyclic carbonates, and so on, the synthesis of polyaziridines with complex macromolecular architectures via ROP of N -sulfonyl aziridines has not been developed until now . Although remarkable progress has been made in recent years regarding the mechanism and the influence of monomers involved ,− in the azaanionic homopolymerization and sequence-controlled copolymerization of several activated aziridines, , the only initiating system usually used was N -benzyl sulfonamide/potassium hexamethyldisilazide (KHMDS) in stoichiometric amounts. Furthermore, other metal-containing initiators, such as n -butyllithium, cesium alkoxide, and 2-azaallyl anions, showed high initiating efficiency for homo-ROP of aziridines or co-ROP with ethylene oxide.…”