Copper(II)-Catalyzed C–H Nitrogenation/Annulation Cascade of Ketene N,S-Acetals with Aryldiazonium Salts: A Direct Access to N2-Substituted Triazole and Triazine Derivatives
Copper(II)-Catalyzed C–H Nitrogenation/Annulation Cascade of Ketene N,S-Acetals with Aryldiazonium Salts: A Direct Access to N2-Substituted Triazole and Triazine Derivatives
复制标题
铜 (II) 催化的 C–H 氮化/环化级联乙烯酮 N,S-缩醛与芳基重氮盐：直接获得 N2 取代的三唑和三嗪衍生物
DOI：
10.1021/acs.orglett.9b04335
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发表时间：
2020
期刊：
影响因子：
5.2
通讯作者：
Zhengkun Yu
中科院分区：
文献类型：
--
作者：
Ping Wu;Yuan He;Hongmei Wang;Yong-Gui Zhou;Zhengkun Yu
直接合成N-2-取代的三唑和三嗪衍生物一直是氮杂环化学中的一个挑战。在铜（II）催化下，烯酮N，S-缩醛，即烷硫基取代的烯胺酮，与芳基重氮盐有效地反应，区域选择性地生成功能多样的N2-取代的1，2，3-三唑和2，3-二氢-1，2，4-三嗪。氧化剂和碱依赖性反应分别产生五元和六元N-杂环产物。该合成方法具有反应底物范围广、反应条件温和、官能团耐受性好等特点。机理研究表明，反应通过烯基偶氮/亚氨基腙中间体进行。
Direct synthesis of N2-substituted triazole and triazine derivatives has been a challenge in N-heterocyclic chemistry. Under copper(II) catalysis ketene N,S-acetals, that is, alkylthio-substituted enaminones, efficiently reacted with aryldiazonium salts to allow the regioselective generation of functionally diverse N2-substituted 1,2,3-triazoles and 2,3-dihydro-1,2,4-triazines. The oxidant and base-dependent reaction yielded the five- and six-membered N-heterocyclic.products, respectively. The synthetic protocol features broad substrate scopes and good functional group tolerance under mild conditions. The mechanistic studies have revealed that the reaction proceeds via alkenyl azo/imino hydrazone intermediates.