Enantioselective Construction of Tertiary α-Alkyl Fluoride via BTM-Catalyzed Fluorination of α-Alkynyl-Substituted Acetic Acids.

The isothiourea-catalyzed enantioselective construction of tertiary α-fluoro stereogenic centers has been demonstrated by using branched alkynyl-substituted acetic acids as starting materials, providing a broad range of optically active tertiary α-alkyl fluorides in high enantioselectivity (up to 97% ee ). Furthermore, this methodology was proven to be scaled up to a Gram scale without loss of enantioselectivity.