Integrated Synthesis of Thienyl Thioethers and Thieno[3,2-b]thiophenes via Benzothiophen-3(2H)-ones

Koichi Mitsudo,* Nanae Habara, Yoshiaki Kobashi, Yuji Kurimoto, Hiroki Mandai, Seiji Suga*
Synlett 2020, 31, 1947–1952.
DOI: 10.1055/s-0040-1707280

Here is described a one-pot procedure for the synthesis of thienyl thioethers. Several thienyl thioethers were successfully synthesized by a TfOH-promoted Friedel–Crafts-type cyclization, a subsequent nucleophilic attack by an arenethiol, and dehydration. This method was applicable to the synthesis of thienoacenes by a Pd-catalyzed dehydrogenative cyclization.