A combination of directing groups and chiral anion phase-transfer catalysis for enantioselective fluorination of alkenes.
We report a catalytic enantioselective electrophilic fluorination of alkenes to form tertiary and quaternary C(sp3)-F bonds and generate β-amino- and β-aryl-allylic fluorides. The reaction takes advantage of the ability of chiral phosphate anions to serve as solid-liquid phase transfer catalysts and hydrogen bond with directing groups on the substrate. A variety of heterocyclic, carbocyclic, and acyclic alkenes react with good to excellent yields and high enantioselectivities. Further, we demonstrate a one-pot, tandem dihalogenation-cyclization reaction, using the same catalytic system twice in series, with an analogous electrophilic brominating reagent in the second step.
Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Jeffrey
J
Wu
Yi-Ming
YM
Wang
Amela
A
Drljevic
Vivek
V
Rauniyar
Robert J
RJ
Phipps
F Dean
FD
Toste
D000475:Alkenes / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D002384:Catalysis; D005459:Fluorides / Q000138:chemical synthesis*; D054879:Halogenation; D006860:Hydrogen Bonding; D008956:Models, Chemical; D015394:Molecular Structure; D044367:Phase Transition; D010710:Phosphates / Q000737:chemistry
D000475:Alkenes; D000838:Anions; D010710:Phosphates; D005459:Fluorides
asymmetric; hydrogen-bonding; organocatalysis