An efficient synthesis of 2-perfluoroalkyl 2H-chromenes 3 (RF = CF3, C2F5) was developed via regioselective cycloaddition of salicylaldehydes 1 and methyl perfluoroalk-2-ynoates 2 in refluxing methanol. 2-Perfluoroalkyl-2H-chromenes 3 was regioselectively obtained in moderate to good yields by using l-proline as organocatalyst. Low toxicity, high regioselectivity, easy available starting materials
通过在回流的
甲醇中
水杨醛1和
全氟烷-2-炔酸甲酯2的区域选择性环加成反应,开发了2-
全氟烷基2 H-
色酮3(R F = CF 3,C 2 F 5)的有效合成方法。通过使用1-脯
氨酸作为有机催化剂,以中等至良好的产率区域选择性地获得了2-
全氟烷基-2 H-
色酮3。该方法可观察到低毒,高区域选择性,容易获得的原料,温和的反应条件。