Enantioselective ring opening of epoxides by fluoride anion promoted by a cooperative dual-catalyst system.
An enantioselective method for the synthesis of beta-fluoroalcohols by catalytic nucleophilic fluorination of epoxides is described. Mild reaction conditions and high selectivity are made possible by the use of benzoyl fluoride as a soluble, latent source of fluoride anion. A chiral amine and chiral Lewis acid serve as cooperative catalysts for desymmetrizations of five- through eight-membered cyclic epoxides, affording products in up to 95% ee. The cocatalytic protocol is also effective for kinetic resolutions of racemic terminal epoxides, which proceed with k(rel) values as high as 300.
Kalow
Julia A
JA
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Doyle
Abigail G
AG
D000438:Alcohols / Q000138:chemical synthesis*; D000838:Anions / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D004852:Epoxy Compounds / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D006844:Hydrocarbons, Cyclic / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis*; D007700:Kinetics; D013237:Stereoisomerism
D000438:Alcohols; D000838:Anions; D004852:Epoxy Compounds; D006844:Hydrocarbons, Cyclic; D006845:Hydrocarbons, Fluorinated; D005459:Fluorides