Stereoselective Nucleophilic Fluoromethylation of Aryl Ketones: Dynamic Kinetic Resolution of Chiral α-Fluoro Carbanions

Although many methods are available for the synthesis of optically enriched monofluoromethyl secondary alcohols, synthesizing optically enriched monofluoromethyl tertiary alcohols remains a challenge. An efficient and easy‐to‐handle nucleophilic fluoromethylation protocol was developed. The current monofluoromethylation showed much higher facial selectivity than the corresponding difluoromethylation and proceeded via a different type of transition state. Excellent stereoselective control at the fluorinated carbon chiral center was found, an effect believed to be facilitated by the dynamic kinetic resolution of the chiral α‐fluoro carbanions. Fluoromethyl fix: An efficient and easy‐to‐handle protocol for the stereoselective synthesis of optically pure monofluoromethyl tertiary alcohols was developed, which showed higher facial selectivity than the corresponding difluoromethylation and proceeded via a different type of transition state. Stereoselective control at the fluorinated carbon chiral center is believed to be facilitated by the dynamic kinetic resolution of the chiral α‐fluoro carbanions.