Wei Zeng-Feng, Ni Li-Jie, Quan Heng, Duan Jiang
Hubei Provincial Key Laboratory of Biomass Fiber and Eco-Dyeing & Finishing, College of Chemistry & Chemical Engineering, Wuhan Textile University Wuhan 430200 China
Key Laboratory of Pesticide & Chemical Biology of the Ministry of Education, College of Chemistry, Central China Normal University Wuhan 430079 P. R. China.
RSC Adv. 2021 May 7;11(28):16955-16961. doi: 10.1039/d1ra01195b. eCollection 2021 May 6.
4-Substituted catechols with different C[double bond, length as m-dash]C bonds as urushiol analogues were synthesized through the a three-step route including reductive amination reaction of 3,4-dihydroxybenzaldehyde with -Boc-piperazine, Boc deprotection, and amidation with various fatty acids. Electrochemical polymerization of these analogues on a copper surface afforded robust coatings with desirable adhesive force, hydrophobicity and thermal stability. Cyclic voltammetry and infrared spectroscopic characterizations revealed that the coating formation of urushiol analogues resulted from the electrooxidation-induced radical coupling of phenoxyl radicals with a phenyl ring and the side chain C[double bond, length as m-dash]C bond. The coating of the urushiol analogue bearing only one side chain C[double bond, length as m-dash]C bond exhibited the best performance in copper corrosion inhibition, with an inhibition efficiency of 99.99% and long-term effect (99.9% after 4 weeks of immersion in 3.5 wt% NaCl). The desired performance of these urushiol analogues suggests that they could be of practical applications as an alternative to the resource-limited natural urushiol.
通过三步路线合成了具有不同碳-碳双键的4-取代儿茶酚作为漆酚类似物，该路线包括3,4-二羟基苯甲醛与-Boc-哌嗪的还原胺化反应、Boc脱保护以及与各种脂肪酸的酰胺化反应。这些类似物在铜表面的电化学聚合提供了具有所需粘附力、疏水性和热稳定性的坚固涂层。循环伏安法和红外光谱表征表明，漆酚类似物的涂层形成是由电氧化诱导的苯氧基自由基与苯环和侧链碳-碳双键的自由基偶联所致。仅带有一个侧链碳-碳双键的漆酚类似物涂层在铜腐蚀抑制方面表现出最佳性能，抑制效率为99.99%，且具有长期效果（在3.5 wt% NaCl中浸泡4周后为99.9%）。这些漆酚类似物的理想性能表明，它们作为资源有限的天然漆酚的替代品可能具有实际应用价值。
