Using the easily accessible 2-azaallyl
anions as initiators, the
one-pot synthesis of well-defined primary amine-ended telechelic polyaziridines
(α-NH2 PAzs) has been achieved through the ring-opening
polymerization (ROP) of N-sulfonyl aziridines followed
by hydrolysis of the diphenylketimine moiety (NCPh2). The 2-azaallyl anions were synthesized from the reaction
of diphenylketimine or N-[aryl-methylene]-α-phenylbenzenemethanamine
with potassium bis(trimethylsilyl) amide (KHMDS) in situ and used
to initiate the ROP of aziridines leading to well-defined α-(Ph2CN)-α′-aryl-ω-NH
PAzs. Along with the diphenylketimine group (NCPh2), aryl functionalities, such as pyridine and triphenylphosphine
moieties, can also be incorporated to the chain end. Chain extension
has been applied for the synthesis of poly(N-sulfonyl
aziridine)-block-poly(ε-caprolactone) (PAz-b-PCL) block copolymers by utilization of the primary amine
end group as initiating sites for the ROP of ε-caprolactone
catalyzed by tin 2-ethyl hexanoate (SnOct2). Taking advantage
of this synthetic approach, core cross-linked multiarm star (CCS)
polymers with an outermost shell having amino and triphenylphosphine
functionalities have been synthesized via “arm-first”
strategy.
An easy, efficient, and solvent/catalyst-free synthetic methodology was developed for the modification of hyperbranched polyethyleneimines (PEI) by ring-opening-addition or ring-opening-polymerization of N-sulfonyl aziridines. Under melting and open-flask conditions, the nucleophilic...
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