Iridium-Catalyzed\nEnantioselective Propargylic C–H\nTrifluoromethylthiolation and Related Processes

The trifluoromethylthio\ngroup (SCF<sub>3</sub>) has gained increasing\nprominence in the field of drug design and development due to its\nunique electronic properties, remarkable stability, and high lipophilicity,\nbut its derivatives remain challenging to access, especially in an\nenantioselective manner. In this Communication, we present an enantioselective\niridium-catalyzed trifluoromethylthiolation of the propargylic C(sp<sup>3</sup>)–H bonds of alkynes. This protocol demonstrates its\nefficacy across a diverse array of alkyne substrates, including B-\nand Si-protected terminal alkynes as well as those derived from natural\nproducts and pharmaceuticals, to give trifluoromethyl thioethers with\ngood to excellent yield and stereoselectivity. Moreover, this protocol\ncould be modified to access enantioenriched difluoromethyl and chlorodifluoromethyl\nthioethers (SCF<sub>2</sub>H and SCF<sub>2</sub>Cl derivatives), significantly\nexpanding the space of synthetically accessible enantioenriched fluoroorganic\ncompounds.