New fluorinating reagents - I. The first enantioselective fluorination reaction

Differding, Edmond; Lang, R. W.

doi:10.1016/s0040-4039(00)82271-6

Cited by 194 publications

(71 citation statements)

References 10 publications

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“…Sulfur tetrafluoride and the following compounds can be used for the controlled introduction of fluorine into organic compounds: Dialkylaminosulfur(IV) fluorides (R 2 NSF 3 ) [44][45][46], arylsulfurtrifluorides [47], fluoroalkylamines (e.g., 2-chloro-1,1,2-trifluoroethyldiethylamine or 1,1,2,3,3,3-hexafluoropropyldiethylamine), tetra-n-butylammonium fluoride, amine hydrofluorides, nitrosyl fluoride, perchloryl fluoride, fluoroxyfluoroalkanes (e.g., CF 3 OF) [48], xenon difluoride [49], CH 3 COOF [50], N-fluoropyridinium salts [51], N-fluorosulfonimides [52], and Selectfluor [53]. They are of commercial value for the fluorination of complex organic compounds, such as pharmaceuticals.…”

Section: Fluorination With Nonmetal Fluoridesmentioning

confidence: 99%

Fluorine Compounds, Organic

Siegemund

Schwertfeger

Feiring

et al. 2016

Ullmann's Encyclopedia of Industrial Chemistry

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Section: Fluorination With Nonmetal Fluoridesmentioning

confidence: 99%

Fluorine Compounds, Organic

Siegemund

Schwertfeger

Feiring

et al. 2016

Ullmann's Encyclopedia of Industrial Chemistry

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“…[65] These chiral electrophilic sources of fluorine provided the anticipated a-fluorocarbonyl compounds upon treatment with various metal enolates. Depending on the substrate, enantioselectivities of up to 70 % ee were observed.…”

Section: Enantioselective Transformationsmentioning

confidence: 99%

Selectfluor: Mechanistic Insight and Applications

et al. 2004

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The replacement of hydrogen atoms with fluorine substituents in organic substrates is of great interest in synthetic chemistry because of the strong electronegativity of fluorine and relatively small steric footprint of fluorine atoms. Many sources of nucleophilic fluorine are available for the derivatization of organic molecules under acidic, basic, and neutral conditions. However, electrophilic fluorination has historically required molecular fluorine, whose notorious toxicity and explosive tendencies limit its application in research. The necessity for an electrophilic fluorination reagent that is safe, stable, highly reactive, and amenable to industrial production as an alternative to very hazardous molecular fluorine was the inspiration for the discovery of selectfluor. This reagent is not only one of the most reactive electrophilic fluorinating reagents available, but it is also safe, nontoxic, and easy to handle. In this Review we document the many applications of selectfluor and discuss possible mechanistic pathways for its reaction.

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“…A major synthetic challenge of fluoroorganic chemistry is the enantioselective generation of fluorinated stereogenic carbon centers [2,19–20]. Initially, chiral auxiliary approaches and diastereoselective reactions were developed, before Differding and Lang found the first stoichiometric asymmetric fluorination of β-ketoester enolates with a chiral N–F ( N -fluoroamine) reagent in 1988 [21]. Later work by Davis [22–23], Takeuchi [24] and their respective coworkers extended this chemistry, while Haufe and coworkers were able to open meso -epoxides asymmetrically with HF equivalents and chiral chromium–salen complexes [25–26].…”

Section: Introductionmentioning

confidence: 99%

Development of the titanium–TADDOLate-catalyzed asymmetric fluorination of β-ketoesters

Hintermann¹,

Perseghini²,

Togni

2011

Beilstein J. Org. Chem.

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SummaryTitanium-based Lewis acids catalyze the α-fluorination of β-ketoesters by electrophilic N–F-fluorinating reagents. Asymmetric catalysis with TADDOLato–titanium(IV) dichloride (TADDOL = α,α,α',α'-tetraaryl-(1,3-dioxolane-4,5-diyl)-dimethanol) Lewis acids produces enantiomerically enriched α-fluorinated β-ketoesters in up to 91% enantiomeric excess, with either F–TEDA (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)) in acetonitrile solution or NFSI (N-fluorobenzenesulfonimide) in dichloromethane solution as fluorinating reagents. The effects of various reaction parameters and of the TADDOL ligand structure on the catalytic activity and enantioselectivity were investigated. The absolute configuration of several fluorination products was assigned through correlation. Evidence for ionization of the catalyst complex by chloride dissociation, followed by generation of titanium β-ketoenolates as key reaction intermediates, was obtained. Based on the experimental findings, a general mechanistic sketch and a steric model of induction are proposed.

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New fluorinating reagents - I. The first enantioselective fluorination reaction

Cited by 194 publications

References 10 publications

Fluorine Compounds, Organic

Fluorine Compounds, Organic

Selectfluor: Mechanistic Insight and Applications

Development of the titanium–TADDOLate-catalyzed asymmetric fluorination of β-ketoesters

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