title: Enantioselective organocatalytic alpha-fluorination of aldehydes.
abstract: The first direct enantioselective catalytic alpha-fluorination of aldehydes has been accomplished. The use of enamine catalysis has provided a new organocatalytic strategy for the enantioselective fluorination of aldehydes to generate alpha-fluoro aldehydes, an important chiral synthon for medicinal agent synthesis. The use of imidazolidinone 1 as the asymmetric catalyst has been found to mediate the fluorination of a large variety of aldehyde substrates with N-fluorobenzenesulfonimide serving as the electrophilic source of fluorine. A diverse spectrum of aldehyde substrates can also be accommodated in this new organocatalytic transformation. While catalyst quantities of 20 mol % were generally employed in this study, successful halogenation can be accomplished using catalyst loadings as low as 2.5 mol %.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Beeson
authors.forename: David W C
authors.initials: DW
authors.lastname: Macmillan
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D002384:Catalysis; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis*; D048289:Imidazolidines / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000588:Amines; D006845:Hydrocarbons, Fluorinated; D048289:Imidazolidines