PEGylated, Water-Soluble, Stable Aminyl Radical,The Journal of Organic Chemistry

当前位置： X-MOL 学术 › J. Org. Chem. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

PEGylated, Water-Soluble, Stable Aminyl Radical
The Journal of Organic Chemistry ( IF 3.3 ) Pub Date : 2017-07-12 00:00:00 , DOI: 10.1021/acs.joc.7b01212
Ying Wang ₁ , Suchada Rajca ₁ , Andrzej Rajca ₁

Affiliation

We report the synthesis and kinetic study of PEGylated, water-soluble aminyl radical 2. The radical possesses four mPEG-3 groups replacing four methyl groups in the tert-butyl groups at the 3- and 6-positions of 1,3,6,8-tetra-tert-butyl carbazyl (TTBC). This structure is designed to mitigate the rapid decomposition of the radical via intramolecular 1,5-hydrogen atom transfer (1,5-HAT) that was observed in its constitutional isomer 1-H with four mPEG-3 groups in the vicinity of the nitrogen-centered radical (1- and 8-positions of TTBC). In dry, degassed acetone at 295 K, the radical 2 has a half-life, τ_1/2 = 49 h (ΔH^‡ = 17.9 ± 0.8 kcal mol^–1), which is 3 orders of magnitude longer than that for 1-H, which decays via 1,5-HAT (τ_1/2 = 48 s, ΔH^‡ = 10.0 ± 0.3 kcal mol^–1). Aminyl radical 2 aggregates at ambient conditions in water and has a half-life, τ_1/2 = 2 h.

中文翻译：

聚乙二醇化，水溶性，稳定的氨基自由基

我们报告了聚乙二醇化的水溶性氨基自由基2的合成和动力学研究。自由基具有4 MPEG-3基团取代在四个甲基叔丁基基团的1,3,6,8-四的3-和6-位叔丁基咔唑（TTBC）。设计该结构的目的是减轻自由基通过分子内1，5-氢原子转移（1,5-HAT）的快速分解，这是在其结构异构体1 -H中在氮附近带有四个mPEG-3基团观察到的中心自由基（TTBC的1和8位）。在295 K的干燥，脱气的丙酮中，自由基2的半衰期为τ1 _/2 = 49 h（ΔH ^‡ = 17.9±0.8 kcal mol^–1），比1 -H长3个数量级，后者通过1,5-HAT衰减（τ1 _/2 = 48 s，ΔH ^‡ = 10.0±0.3 kcal mol ^–1）。氨基自由基2在环境条件下在水中聚集，半衰期为τ1 _/2 = 2 h。

更新日期：2017-07-13

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文