A versatile synthetic approach to polypeptide based rod-coil block copolymers by click chemistry
A versatile synthetic approach to polypeptide based rod-coil block copolymers by click chemistry
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DOI：
10.1021/ma070579m
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发表时间：
2007-08-07
期刊：
影响因子：
5.5
通讯作者：
Lecommandoux, Sebastien
中科院分区：
文献类型：
--
作者：
Agut, Willy;Taton, Daniel;Lecommandoux, Sebastien
通过Huisgen的1，3-偶极环加成反应（点击化学），由含叠氮和炔官能团的均聚物合成了由刚性聚谷氨酸γ-苄酯（PBLG）序列和聚甲基丙烯酸2-（二甲氨基）乙酯（PDMAEMA）嵌段组成的定义明确的嵌段共聚物。使用适当的α-ω-官能化引发剂将这些官能团引入PBLG和PDMAEMA前体两者的α-位以引发相应单体的活性/受控聚合。以二甲基甲酰胺为溶剂，由含氨基的α-炔和α-叠氮双官能引发剂，在室温下通过γ-苄基-L-谷氨酸N-羧酸酐的开环聚合反应合成了α-炔-和α-叠氮基-PBLG。至于α-炔-PDMAEMA和α-叠氮基-PDMAEMA，它们是通过在60 ℃下在作为溶剂的四氢呋喃中的甲基丙烯酸2-（二甲氨基）乙酯的铜介导的原子转移自由基聚合获得的。一方面，α-叠氮基-PBLG与α-炔-PDMAEMA的铜（I）催化的1，3-偶极环加成偶联反应，另一方面，α-炔-PBLG与α-叠氮基-PDMAEMA的铜（I）催化的1，3-偶极环加成偶联反应方便地在DMF中进行，得到目标PBLG-b-PDMAEMA二嵌段共聚物。通过将该均聚物保留在柱色谱的固定相上，促进了略微过量使用的残留PDMAEMA的去除。基于尺寸排阻色谱法，IR和NMR分析，点击化学被发现是定量的，第一次产生基于多肽和乙烯基聚合物的混合二嵌段共聚物。
Well-defined block copolymers composed of a rigid poly(gamma-benzyl-L-glutamate) (PBLG) sequence and a poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) block were synthesized by Huisgen's 1,3-dipolar cycloaddition (click chemistry) from homopolymers containing azide and alkyne functionalities. These functional groups were introduced in the alpha-position of both PBLG and PDMAEMA precursors using appropriate alpha-omega-functionalized initiators to trigger the living/controlled polymerization of the corresponding monomers. Both alpha-alkyne- and alpha-azido-PBLGs were synthesized by ring-opening polymerization of gamma-benzyl-L-glutamate N-carboxyanhydride at room temperature from amino-containing alpha-alkyne and alpha-azide difunctional initiators, using dimethylformamide as solvent. As for alpha-alkyne-PDMAEMA and alpha-azido-PDMAEMA, they were obtained by copper-mediated atom transfer radical polymerization of 2-(dimethylamino)ethyl methacrylate at 60 degrees C in tetrahydrofuran as solvent. The copper(I)-catalyzed 1,3-dipolar cycloaddition coupling reactions of the alpha-azido-PBLG with the alpha-alkyne-PDMAEMA, in the one hand, and of the alpha-alkyne-PBLG with the alpha-azido-PDMAEMA, on the other hand were conveniently performed in DMF, affording the targeted PBLG-b-PDMAEMA diblock copolymers. Removal of the residual PDMAEMA used in slight excess was facilitated by the retention of this homopolymer onto the stationary phase of the column chromatography. On the basis of size exclusion chromatography, IR and NMR analyses, click chemistry was found to be quantitative, yielding for the first time hybrid diblock copolymers based on a polypeptide and a vinylic polymer.