We have developed a mild and practical tandem trifluoromethylselenolation/cyclization of alkenes using trifluoromethyl selenoxide and Tf₂O as a catalyst, affording CF₃Se-containing oxindoles and benzoxazines in acceptable yields. A mechanism involving electrophilic CF₃Se species is proposed.

Abstract

In this study, we have developed the tandem trifluoromethylselenolation/cyclization of alkenes to synthesize the CF₃Se-containing heterocycles with trifluoromethyl selenoxide as the trifluoromethylselenolation reagent and Tf₂O as the catalyst. This transformation featured mild conditions and easy operation. Both CF₃Se-containing oxindoles and benzoxazines could be obtained in useful yields. Based on the preliminary results and previous reports, a mechanism involving the generation of the electrophilic CF₃Se species was proposed.