title: From bifunctional to trifunctional (tricomponent nucleophile-transition metal-lewis acid) catalysis: the catalytic, enantioselective α-fluorination of acid chlorides.
abstract: We report in full detail our studies on the catalytic, asymmetric α-fluorination of acid chlorides, a practical method that produces an array of α-fluorocarboxylic acid derivatives in which improved yield and virtually complete enantioselectivity are controlled through electrophilic fluorination of a ketene enolate intermediate. We discovered, for the first time, that a third catalyst, a Lewis acidic lithium salt, could be introduced into a dually activated system to amplify yields of aliphatic products, primarily through activation of the fluorinating agent. Through our mechanistic studies (based on kinetic data, isotopic labeling, spectroscopic measurements, and theoretical calculations) we were able to utilize our understanding of this "trifunctional" reaction to optimize the conditions and obtain new products in good yield and excellent enantioselectivity.
authors.affiliation: Department of Chemistry, New Chemistry Building, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Erb
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Paull
authors.forename: Travis
authors.initials: T
authors.lastname: Dudding
authors.forename: Lee
authors.initials: L
authors.lastname: Belding
authors.forename: Thomas
authors.initials: T
authors.lastname: Lectka
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D002712:Chlorides / Q000737:chemistry*; D054879:Halogenation; D058116:Lewis Acids / Q000737:chemistry*; D008672:Metals, Alkali / Q000737:chemistry; D013237:Stereoisomerism; D028561:Transition Elements / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D002712:Chlorides; D058116:Lewis Acids; D008672:Metals, Alkali; D028561:Transition Elements