A convenient approach to pyridine quaternary ammonium salts containing enamine fragment has been developed, which features a trifluoromethyl sulfonic anhydride mediated regioselective addition process of pyridine with ynamides. Using this method, a variety of substituted pyridine quaternary ammonium salts containing enamine fragment 3a~3m were prepared in moderate to excellent yields with high regioselectivities (Z∶E up to 20∶1). Keywords ynamides; pyridine; addition reaction; pyridine quaternary ammonium salt 制备简单、性质稳定的炔酰胺, 其分子中的氮原子 以 σ 键形式分别与酰基和炔基相连, 产生独特 p-π 共轭 体系, 该体系受吸电子型酰基调控, 直接改变了两个炔 键碳的反应活性 [1][2] . 从而使炔酰胺结构中叁键 α 位碳 原子具有亲电性, β 位碳原子具有亲核性 [3] . 使用不同 酸、碱活化炔酰胺时, 反应活性位点会有所不同, 使炔 酰胺在反应中出现较高的区域选择性(Scheme 1). 在炔 酰胺参与的反应中, 多种活化模式被广泛研究, 主要包 括金属试剂活化 [4] 、 布朗斯特酸活化 [5] 、 路易斯酸活化 [6] 、 亲电试剂(卤素)活化 [7] 、碳正离子活化 [8] . 既可作为亲电 试剂又可作为亲核试剂的炔酰胺被广泛用于加成反应、 氧化反应、还原反应、环加成反应、关环复分解反应 (RCM)反应、自由基反应和金属催化的环异构化反应 中 [9] . 近年来, 本课题组也将炔酰胺用于亚胺鎓的加成 环化, 与吲哚、酮的选择性加成, 与伯胺、仲胺的氢胺 化反应及叔胺导向的芳环 sp 2 杂化 C-H 活化加成反应 中 [10] .图式 1 炔酰胺结构中三键的电性分析 Scheme 1 Electrical analysis of three bonds in ynamides 2-氨基吡啶、吡啶鎓盐及吡啶 N-氧化物也被用来与
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