He Yan, Wang Fang, Zhang Xinying, Fan Xuesen
School of Chemistry and Chemical Engineering, School of Environment, Collaborative Innovation Centre of Henan Province for Green Manufacturing of Fine Chemicals, Henan Key Laboratory of Organic Functional Molecule and Drug Innovation, Henan Normal University, Xinxiang, Henan 453007, China.
Chem Commun (Camb). 2017 Apr 4;53(28):4002-4005. doi: 10.1039/c6cc10227a.
A novel and efficient synthesis of tetrahydropyridine (THP)-, dihydropyrrole (DHP)-, or tetrahydroazepine (THA)-3-carboxylates via cascade reactions of inactivated cyclic amines with CO and alcohols is presented. To our knowledge, this should be the first example in which functionalized N-heterocycles were prepared directly from Pd-catalyzed C(sp)-H dehydrogenation and C(sp)-H carbonylation of saturated cyclic amines. Moreover, the DHP-3-carboxylates thus obtained could readily undergo an oxidative aromatization to give pyrrole-3-carboxylates by using O as a green oxidant. Notable features of the methods developed herein include simple substrates, high efficiency and excellent atom-economy, mild reaction conditions, and broad substrate scope.
本文报道了一种通过失活环胺与一氧化碳和醇的串联反应高效合成四氢吡啶（THP）-、二氢吡咯（DHP）-或四氢氮杂卓（THA）-3-羧酸酯的新方法。据我们所知，这应该是首例直接由饱和环胺的钯催化C(sp)-H脱氢和C(sp)-H羰基化反应制备功能化氮杂环的实例。此外，由此得到的DHP-3-羧酸酯可以很容易地通过使用氧气作为绿色氧化剂进行氧化芳构化反应生成吡咯-3-羧酸酯。本文所开发方法的显著特点包括底物简单、效率高、原子经济性好、反应条件温和以及底物范围广。
