A vast variety of oxidation procedures is known to obtain 2,2,6,6-tetramethylpiperidinyl-4-oxyl (TEMPO) moieties from its piperidinyl precursor. However, up to now no comprehensive study has been performed concerning the performance and feasibility for lab-scale synthesis. With the focus on the ease of synthesis, occurring impurities, the reaction yield and the degree of oxidation (DoO), this study represents a thorough investigation of different oxidation processes yielding N -oxyl radicals in a one-step procedure. The resulting materials were investigated by redox titration and electron spin resonance spectroscopy to determine the DoO, which is the determining parameter for the yield of this oxidation reaction. The most promising procedures have been transferred to a polymeric material to evaluate the feasibility of the catalysts for more complex substrates.

中文翻译：

---

N,N,N,2,2,6,6-七甲基-哌啶-4-氯化铵氧化成水溶性N-氧基自由基：比较研究

已知有多种氧化过程可从其哌啶基前体获得 2,2,6,6-四甲基哌啶基-4-氧基 (TEMPO) 部分。然而，到目前为止，尚未对实验室规模合成的性能和可行性进行全面研究。本研究重点关注合成的难易程度、存在的杂质、反应产率和氧化程度 (DoO)，它代表了对一步法产生 N-氧基自由基的不同氧化过程的彻底研究。通过氧化还原滴定和电子自旋共振光谱研究所得材料以确定DoO，这是该氧化反应产率的决定性参数。