Scheme 113. Preparation of SF 5 -Containing Arylboronic Acids and Use in Conia−Ene Cyclizations a a Reagents and conditions: (a) i-PrMgBr (1.2 equiv), B(OMe) 3 THF, −78 to 25 °C (65%); (b) 429, PhMe (3−73%). Scheme 114. Preparation of SF 5 -Containing Binaphthyl Compounds a a Reagents and conditions: (a) 428, Pd(PPh 3 ) 4 (10%), K 2 CO 3 , DMF; (b) BBr 3 (75%); (c) POCl 3 ; (d) H 2 O. Scheme 115. Asymmetric Protonation via SF 5 -Containing Acid 436 a a Reagents and conditions: (a) 436 (catalytic).

Herein, we report a highly regioselective gold-catalyzed formal hydration of propargylic gem-difluorides. Not only does this transformation provide access to versatile fluorinated building blocks that were difficult or hardly possible to access beforehand, but it also represents a rare case of a highly regioselective gold-catalyzed hydroalkoxylation of internal alkynes and puts forward the utility of the difluoromethylene unit as a directing group in catalysis.

The trifluoromethyl tetrafluoro‐λ6‐sulfanyl (CF3SF4) group is both extraordinarily lipophilic and profoundly electron withdrawing, properties associated with polar hydrophobicity. Utilization of the CF3SF4 group to prepare novel materials or biologically active agents will not be possible without new methods for the synthesis of aliphatic CF3SF4‐substituted building blocks. To advance those studies, trichloromethanesulfenyl chloride was conveniently converted to trans‐trifluoromethyl tetrafluoro‐λ6‐sulfanyl chloride (CF3SF4Cl) by oxidative chlorofluorination. Triethylborane‐promoted addition reactions of trans‐CF3SF4Cl to substituted olefins and alkynes yielded a variety of new materials. Those addition products were subsequently transformed to CF3SF4‐substituted carboxylic acids, CF3SF4‐substituted ketones, and a CF3SF4‐substituted aldehyde.