Metal‐free, Visible‐Light‐Mediated Direct Csp
<sup>2</sup>
−H Radical Mono‐ and Bis‐trifluoromethylation of Coumarins and Bioactivity Evaluation
作者:Xiang Yu、Peng Dai、Yu‐Chuan Zhu、Peng Teng、Wei‐Hua Zhang、Chao Deng
DOI:10.1002/cctc.201801332
日期:2018.11.22
A clean, transition metal‐ and oxidant‐free photochemical protocol was described for the direct trifluoromethylation of coumarins with Togni reagent. The reaction proceeded smoothly under mild condition to afford regioselective 3‐trifluoromethyl coumarins, moreover novel bis‐trifluoromethylated coumarins were formed. Preliminary bioactivity evaluation on some products showed potential antifungal activities
Mn(OAc)3-mediated direct Csp2-H radical trifluoromethylation of coumarins with CF3SO2Na (Langlois reagent) to afford selective 3-trifluoromethyl coumarins in moderate to good yields is described. This methodology can also be applied to the trifluoromethylation of quinolinones and pyrimidinones.