Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
J Am Chem Soc. 2017 Nov 15;139(45):16100-16104. doi: 10.1021/jacs.7b10076. Epub 2017 Oct 31.
Nucleophilic aromatic substitution (SAr) is a direct method for arene functionalization; however, it can be hampered by low reactivity of arene substrates and their availability. Herein we describe a cation radical-accelerated nucleophilic aromatic substitution using methoxy- and benzyloxy-groups as nucleofuges. In particular, lignin-derived aromatics containing guaiacol and veratrole motifs were competent substrates for functionalization. We also demonstrate an example of site-selective substitutive oxygenation with trifluoroethanol to afford the desired trifluoromethylaryl ether.
亲核芳香取代（SAr）是芳基功能化的直接方法；然而，芳环底物的低反应性及其可用性可能会对此造成阻碍。在此，我们描述了一种使用甲氧基和苄氧基作为亲核基团的阳离子自由基促进的亲核芳香取代。特别是，含有愈创木酚和藜芦醇基序的木质素衍生芳烃是合适的功能化底物。我们还展示了一例用三氟乙醇进行选择性取代氧化的实例，以得到所需的三氟甲基芳基醚。
