α‑Selective <i>syn</i>-Carbotrifluoromethylthiolationof Alkynes

Trifluoromethylthiolative difunctionalization of alkynes typically proceeds in an <i>anti</i>-fashion delivering the SCF₃ group in the β-position (<i>anti</i>-Markovnikov). Herein, we disclose a vicinal <i>syn</i>-arylation-trifluoromethylthiolation of alkynes enabling α-selective introduction of the SCF₃ group (Markovnikov). The unique selectivity was achieved via a merge of Ni-catalyzed carbomagnesiation with a subsequent Cu-mediated trifluoromethylthiolation of the resulting vinyl-magnesium species. The former component of the sequential process determines both the regio- and stereoselectivity of the overall transformation.