Construction of 6H-benzo[c]thiochromenes via a tandem reaction of arynes with thionoesters

A mild and transition-metal free tandem reaction for the construction of 6H-benzo[c]thiochromenes has been developed. Thionoesters react with two molecules of arynes through a Diels-Alder cycloaddition/nucleophilic arylation process to afford 6-alkoxy-6-aryl-6H-benzo[c]thiochromenes in 37-80% yields. In addition, the Diels-Alder cycloaddition/aromatization tandem reaction of thionoesters with one molecule of aryne provides the construction of 6-alkoxyl-6H-benzo[c]thiochromenes in 51-75% yields.

Automated summary

A mild and transition-metal free tandem reaction has been developed for the construction of 6H-benzo[c]thiochromenes. Thionoesters react with arynes to afford different structures of products in yields ranging from 37-80% and 51-75%.