Chiral Tertiary Amine Catalyzed Asymmetric [4 + 2] Cyclization of 3-Aroylcoumarines with 2,3-Butadienoate

oleh: Jun-Lin Li, Xiao-Hui Wang, Jun-Chao Sun, Yi-Yuan Peng, Cong-Bin Ji, Xing-Ping Zeng

Format: Article
Diterbitkan: MDPI AG 2021-01-01

Deskripsi

Coumarins and 2<i>H</i>-pyran derivatives are among the most commonly found structural units in natural products. Therefore, the introduction of 2<i>H</i>-pyran moiety into the coumarin structural unit, i.e., dihydrocoumarin-fused dihydropyranones, is a potentially successful route for the identification of novel bioactive structures, and the synthesis of these structures has attracted continuing research interest. Herein, a chiral tertiary amine catalyzed [4 + 2] cyclization of 3-aroylcoumarines with benzyl 2,3-butadienoate was reported. In the presence of Kumar’s 6’-(4-biphenyl)-β-iso-cinchonine, the desired dihydrocoumarin-fused dihydropyranone products could be obtained in up to 97% yield and 90% ee values.