Trifluoromethyl Selenoxides: Electrophilic Reagents for C-H Trifluoromethylselenolation of (Hetero)Arene.

The trifluoromethylselenyl group (CF 3 Se) has become an emerging fluorinated moiety in synthetic chemistry due to its high Hansch lipophilicity parameter and strong electron-withdrawing effect. The trifluoromethylselenolation is hampered by limited synthetic methods and related reagents. Herein, we designed and synthesized the new electrophilic trifluoromethylselenolation reagents, trifluoromethyl selenoxides, which are easy to prepare and easy-to-handle and are not moisture or air sensitive. The selenoxides are successfully applied to metal-free C-H trifluoromethylselenolation of a series of (hetero)arenes.