Base‐Promoted Diastereoselective Addition of 2‐Aryloxy‐2‐Fluoroketones to <i>N</i>‐(<i>tert</i>‐Butylsulfinyl)Imines

Abstract The asymmetric construction of a quaternary fluorine‐containing stereogenic carboncenter is highly valuable for the development of fluoroine‐containing bioactive molecules. Herein, a base‐promoted, diastereoselective Mannich‐type reaction of 2‐aryloxy‐2‐fluoroketones with N ‐( tert ‐butylsulfinyl)imines has been developed. A number of the addition products featuring a fluorinated quaternary stereocarbon centre and a β‐fluoroamine structural motif have been readily obtained in good yields with moderate to good diastereoselectivities. The absolute configuration of the major diasteromer was determined by X‐ray crystallography analysis, and a closed transition‐state mode was proposed to explain the stereochemical outcome of this reaction. In addition, the addition product was efficiently converted into a α‑fluoro‐β‐amino alcohol through desulfinylation followed by reduction of the carbonyl group.