Polymer-bound thiol groups on poly(2-oxazoline)s

A new 2-oxazoline monomer with a protected thiol group, 2-[2-(4-methoxybenzyl-sulfanyl)ethyl]-2-oxazoline, MOB-SOx, was synthesized from commercially available compounds. MOB-SOx and 2-ethyl-2-oxazoline (EtOx) were simultaneously polymerized yielding well defined copolymers with narrow molar mass distributions and target polymer chain length. The copolymerization was initiated by N-methyl-2-methyl-2-oxazolinium triflate (MeOx-OTf). After quantitative deprotection, poly(2-oxazoline) with pendant thiol groups was obtained. The thiol groups were quantitatively added to the double bond of N-phenyl-acrylamide (PhA) and benzylmaleimide (BzM). Graft copolymers were obtained by reaction of those SH containing polymers with poly(2-methyl-2-oxazoline)s bearing acrylamide (PMeOx(10)A) and maleimide (PMeOx(10)M) as terminal reactive groups.