Direct radical trifluoromethylthiolation and thiocyanation of aryl alkynoate esters: mild and facile synthesis of 3-trifluoromethylthiolated and 3-thiocyanated coumarins

A mild and convenient oxidative radical cyclization of aryl alkynoate esters for the synthesis of 3-trifluoromethylthiolated and 3-thiocyanated coumarins has been developed using AgSCF3 and AgSCN as the corresponding radical sources, respectively. This protocol is characterized by readily available starting materials, excellent functional group tolerance and good yields.