Trifluoromethylborylation of Unactivated Alkenes via an Electron Donor–Acceptor (EDA) Complex

This communication describes a straightforward method for the trifluoromethylborylation of unactivated alkenes. The reaction proceeds through the formation of an electron donor-acceptor (EDA) complex between a trifluoromethylthiophenium salt and bis(catechol)diboron under broad-spectrum white-light irradiation. Due to the mild reaction conditions, the trifluoromethylborylation tolerates a wide range of functional groups, including esters, acids, alcohols, epoxides, and a variety of heterocycles. The reaction does not require a transition metal catalyst and tolerates both air and moisture, proceeding under concentrated conditions (1 M). Mechanistic studies provide a general reaction coordinate for the overall transformation.