Visible-Light-Induced C(sp<sup>2</sup>)–C(sp<sup>3</sup>) Coupling Reaction for the Regioselective Synthesis of 3-Functionalized Coumarins
作者:Ke Zhang、Li Qiao、Jianwei Xie、Zhenwei Lin、Hanjie Li、Ping Lu、Yanguang Wang
DOI:10.1021/acs.joc.1c00848
日期:2021.7.16
A photocatalysis strategy for the regioselective synthesis of 3-functionalized coumarins is reported. With visible light irradiation, a direct and regioselective C(sp2)–C(sp3) coupling reaction of 3-(2-hydroxyphenyl)acrylates with ethers or thioethers occurs by using Ru(bpy)3Cl2·6H2O as a photocatalyst and TBHP as an oxidant. The cascade process involves alkenylation of the C(sp3)–H bond of ethers
报道了一种用于区域选择性合成 3 官能化香豆素的光催化策略。在可见光照射下,3-(2-羟基苯基)丙烯酸酯与醚或硫醚发生直接和区域选择性的C(sp 2 )–C(sp 3 )偶联反应,使用Ru(bpy) 3 Cl 2 ·6H 2 O作为光催化剂和TBHP作为氧化剂。级联过程涉及 C(sp 3)-H 键的醚和内酯化,提供 3-烷基化香豆素作为最终产品。该方法的特点是底物范围广、反应条件温和、操作简单。3-烷基化香豆素的合成可以通过一锅法实现,从市售的水杨醛开始。