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
regioselective synthesis of 3-trifluoromethylated coumarins. The reaction was performed by using the Togni reagent as the CF3 source under mild conditions and showed good functional- group tolerance. The scope of this copper-mediated method was further expanded to the synthesis of 3-trifluoromethylated carbostyrils starting from ortho-aminocinnamic derivatives. Interestingly, a sequential one-pot synthesis of