Base‐Promoted Diastereoselective Addition of 2‐Aryloxy‐2‐Fluoroketones to N‐(tert‐Butylsulfinyl)Imines.

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. [ABSTRACT FROM AUTHOR]