The reaction of 5-hydroxymethylfurfural (5-HMF) with arenes in superacidic trifluoromethanesulfonic acid (triflic acid, TfOH) as the solvent at room temperature for 1–24 h gives rise to 5-arylmethylfurfurals (yields of 17–91%) and 2-arylmethyl-5-(diarylmethyl)furans (yields of 10–37%). The formation of these two types of reaction products depends on the nucleophilicity of the arene. The same reactions under the action of acidic zeolites H-USY in high pressure tubes at 130 °C for 1 h result in the formation of only 5-arylmethylfurfurals (yields of 45–79%). 2,5-Diformylfuran (2,5-DFF) in the reaction with arenes under the action of AlBr3 at room temperature for 1 h leads to 5-(diarylmethyl)furfurals (yields of 51–90%). The reactive protonated species of 5-HMF and 2,5-DFF were characterized by NMR spectroscopy in TfOH and studied by DFT calculations. These reactions show possibilities of organic synthesis based on biomass-derived 5-HMF and 2,5-DFF.
5-羟甲基糠醛(5-HMF)在超酸性三氟甲磺酸(三氟甲磺酸,TfOH)溶剂中与芳烃在室温下反应1-24小时,产生5-芳基甲基糠醛(产率为17-91%)和2-芳基甲基-5-(二芳基甲基)呋喃(产率为10-37%)。这两种类型的反应产物的形成取决于芳烃的亲核性。在130°C高压管中,相同的反应在酸性沸石H-USY的作用下进行1小时,结果只形成5-芳基甲基糠醛(产率为45-79%)。2,5-二甲酰基呋喃(2,5-DFF)在室温下与芳烃在AlBr3的作用下反应1小时,导致5-(二芳基甲基)糠醛(产率为51-90%)。通过NMR光谱在TfOH中表征了5-HMF和2,5-DFF的反应质子化物种,并通过DFT计算进行了研究。这些反应展示了基于生物质衍生的5-HMF和2,5-DFF的有机合成可能性。