MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China.
Biopolymers. 2019 Apr;110(4):e23261. doi: 10.1002/bip.23261. Epub 2019 Feb 12.
Polypeptoids synthesized from N-substituted glycine N-carboxyanhydrides (NNCAs) are widely applied in biological fields. The effect of side groups in NNCA polymerizations is a key to develop novel polypeptoids with complex topologies and constituents. In this work, density functional theory (DFT) calculations are employed to investigate the propagation of a series of alkyl substituted NNCAs with solvation model. According to both computational and experimental results, carbonyl addition is confirmed as rate determining step and steric hindrance is recognized as the major factor of low reactivity in β-C branched NNCAs. However, in linear and γ-C branched case, aggregation of side groups instead of bulkiness is considered responsible for low polymerization rate.
聚肽酯是由 N-取代甘氨酸 N-羧酸酐（NNCAs）合成的，广泛应用于生物领域。侧基在 NNCAs 聚合中的作用是开发具有复杂拓扑结构和组成的新型聚肽酯的关键。在这项工作中，采用密度泛函理论（DFT）计算对一系列带有溶剂化模型的烷基取代 NNCAs 的聚合进行了研究。根据计算和实验结果，证实了羰基加成是决定反应速率的步骤，空间位阻是β-C 支化 NNCAs 低反应性的主要因素。然而，在直链和γ-C 支化的情况下，侧基的聚集而不是体积庞大被认为是导致聚合速率低的原因。
