2,3‐Dichloro‐5,6‐Dicyano‐1,4‐Benzoquinone (DDQ)‐Mediated Tandem Oxidative Coupling/Intramolecular Annulation/Dehydro‐Aromatization for the Synthesis of Polysubstituted and Fused Pyridines
作者:Dongping Cheng、Zhiteng Deng、Xianhang Yan、Mingliang Wang、Xiaoliang Xu、Jizhong Yan
DOI:10.1002/adsc.201900956
日期:2019.11.5
A DDQ‐mediated tandem reaction of 1,3‐diarylpropenes and β‐enaminoesters/4‐aminocoumarins is disclosed. It involves oxidative coupling, intramolecular annulation and dehydro‐aromatization reaction, which provides an efficient and mild method for the synthesis of polysubstituted and fused pyridines under metal‐free conditions.
Isothiourea and Brønsted Acid Cooperative Catalysis: Enantioselective Construction of Dihydropyridinones
作者:Yu-Chen Zhang、Rui-Long Geng、Jin Song、Liu-Zhu Gong
DOI:10.1021/acs.orglett.0c00461
日期:2020.3.20
Asymmetric annulation of bench-stable α,β-unsaturated aryl esters with enamines was realized via cooperative catalysis of chiral isothiourea and Brønsted acid. This reaction proceeds via a chiral α,β-unsaturatedacyl ammonium intermediate and offers a rapid access to functionalized 3,4-dihydropyridin-2-ones in high yields and excellent enantioselectivities.
The first example of a Cu‐catalyzed and 4‐OH‐TEMPO mediated intermolecular [3+3] annulation of saturated ketones with β‐enamino esters is reported herein, which was successfully used for the synthesis of versatile nicotinates through sequential β‐C(sp3)‐H bond alkenylation, enamine‐carbonyl condensation and aromatization. This protocol tolerates a variety of functional groups, thereby providing a practical
Copper-Catalyzed Tandem Reaction of Enamino Esters with <i>ortho</i>
-Halogenated Aromatic Carbonyls: One-Pot Approach to Functionalized Quinolines
作者:Fei Peng、Jin Liu、Lili Li、Zhiwei Chen
DOI:10.1002/ejoc.201701472
日期:2018.2.7
tandem reaction was developed for the efficientsynthesis of functionalized quinolones. The C–Cbondformation and C–N coupling reaction of enamino esters and ortho‐halogenated aromatic carbonyl compounds gave products in moderate to good yields. A successful gram‐scale protocol and synthesis of a thieno[3,2‐b]pyridine derivative show further applications of this approach.
为了有效合成功能化喹诺酮,开发了铜催化串联反应。烯氨基酯与邻卤代芳族羰基化合物的C–C键形成和C–N偶联反应使产物收率适中至良好。成功的克级规程和噻吩并[3,2- b ]吡啶衍生物的合成表明了该方法的进一步应用。