A facile amino-functionalization of poly(2-oxazoline)s%26apos; distal end through sequential azido end-capping and Staudinger reactions

作者：Osawa Shigehito; Ishii Takehiko; Takemoto Hiroyasu; Osada Kensuke; Kataoka Kazunori

来源：European Polymer Journal, 2017, 88: 553-561.

DOI：10.1016/j.eurpolymj.2016.11.029

• Poly(2-oxazoline)
• Amino end-functionalization
• Azido termination
• Amino conversion
• Staudinger reaction

Facile and quantitative method to introduce primary-amino group into the distal chain end of poly(2-substituted 2-oxazoline)s (POx)s, which have attracted progressive interest as platform polymers for various bio-functionality materials, was established here via twostep reactions; First, termination of cationic polymerization of 2-oxazolirie using sodium azide as the end-capping reagent, followed by the conversion of the azido group to an amino group using triphenylphosphine (TPP) by the Staudinger reaction. The azido introduction step and the subsequent amino conversion step was accomplished within 1 h and 3 h, respectively, to ultimately obtain omega-amino-poly(2-ethyl-2-oxazoline) (PEtOx-NH2) with 96% functionality. The synthesized PEtOx-NH2 was subjected to ring-opening polymerization of N-epsilon-trifluoroacetyl-L-lysine N-carboxy anhydride (Lys(TFA)-NCA) to successfully obtain the block copolymer PEtOx-b-PLys(TFA), which can be utilized as a platform polymer to develop polymer therapeutics, thus, demonstrating the versatility of the presently reported procedure for further functionalization of POx derivatives.

• 出版日期2017-3