Photocatalytic Radical Bis(trifluoromethyl)carbinolation of Alkenes and Heteroarenes

Structural modification of drug candidates with fluorine atoms has revolutionized drug discovery, frequently enhancing pharmacological properties. However, the strategic integration of privileged bis(trifluoromethyl)carbinol moiety remains challenging, primarily due to the overreliance on closed-shell strategies typically involving toxic gaseous hexafluoroacetone. Alternative radical-based strategies exist but are constrained by the inherently weak electrophilicity of the key bis(trifluoromethyl)carbinol radical intermediate, significantly limiting the scope of accessible transformations. Here we report the development of a novel masked bis(trifluoromethyl)carbinolation reagent, enabling the efficient generation of bis(trifluoromethyl)carbinol radical species with significantly enhanced electrophilicity under mild photocatalytic conditions. This approach facilitates chloro- and oxy-bis(trifluoromethyl)carbinolation of versatile alkenes, alongside highly selective C2-H bis(trifluoromethyl)carbinolation of diverse heteroarenes, providing streamlined access to a structurally diverse array of alkyl and aryl bis(trifluoromethyl)carbinols previously considered synthetically challenging.