Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.
Org Biomol Chem. 2019 Feb 20;17(8):2110-2115. doi: 10.1039/c8ob02899k.
Phenols are extremely valuable building blocks in the areas of pharmaceuticals, natural products, materials and catalysts. In order to carry out modifications on phenols, the phenolic oxygen is routinely protected to prevent unwanted side reactions. Presently many of the protecting groups available can require harsh conditions, specialist equipment, expensive or air/moisture-sensitive reagents to install and remove. Here we introduce the use of the tetrafluoropyridyl (TFP) group as a general protecting group for phenols. TFP can be installed in one step with no sensitivity to water or air, and it is stable under a range of commonly employed reaction conditions including acid and base. The TFP protecting group is readily cleaved under mild conditions with quantitative conversion to the parent phenol, observed in many cases in less than 1 hour.
酚类化合物在药物、天然产物、材料和催化剂领域具有极高的应用价值。为了对酚类化合物进行修饰，通常需要保护酚羟基，以防止不必要的副反应发生。目前，许多可用的保护基团需要苛刻的条件、专业设备、昂贵或对空气/湿度敏感的试剂来进行安装和去除。在这里，我们介绍了使用四氟吡啶基（TFP）作为酚类化合物的通用保护基团。TFP 可以在一步反应中引入，对水和空气不敏感，并且在包括酸和碱在内的一系列常用反应条件下稳定。TFP 保护基在温和条件下易于去除，定量转化为母体酚，在许多情况下，转化时间不到 1 小时。
