Enantioselective Fluoroamination: 1,4‐Addition to Conjugated Dienes Using Anionic Phase‐Transfer Catalysis

Abstract

Phasentransferkatalyse mit chiralen Anionen wurde für enantioselektive Fluorcyclisierungsreaktionen von 1,3‐Dienen eingesetzt. Die Methode liefert ungewöhnliche fluorierte Benz[f]isochinoline und Octahydroisochinoline in hohen Ausbeuten mit bis zu 96 % ee. Ein neues fluoriertes Aminreagens wurde entwickelt, das für diese Umsetzung besser war als Selectfluor.

Catalytic Intramolecular Aminofluorination, Oxyfluorination, and Carbofluorination with a Stable and Versatile Hypervalent Fluoroiodine Reagent

“…[4,6] Fluorocyclization reactions for the synthesis of oxygen-containing rings have also been an attractive synthetic method for the introduction of the fluorine functionality into organic molecules. [6c,m,7] As omewhat less developed but very challenging area involves carbofluorination reactions for the synthesis of fluorinecontaining isocyclic compounds.…”

Modern Approaches for Asymmetric Construction of Carbon–Fluorine Quaternary Stereogenic Centers: Synthetic Challenges and Pharmaceutical Needs

“…In 2013, the Toste group reported the enantioselective 1,4-aminofluorocyclization of conjugated 1,3-dienes 179 catalyzed by lipophilic chiral phosphate as an anionic phase-transfer catalyst, leading to the 6- endo -trig cyclization to provide allylic fluorides 188 bearing a C–F quaternary stereocenter (Scheme 60). 191 For evaluation of the BINOL-derived phosphate catalysts, with the aim of enhancing the solubility and selectivity of Selectflor without compromising reactivity, ( R )-C45 was chosen as the superior candidate to produce higher enantiomeric excess. Additionally, the inorganic base was found to be critical to control the reactivity and selectivity in this tandem transformation.…”

Cinchona Alkaloids as Organocatalysts in Enantioselective Halofunctionalization of Alkenes and Alkynes

“…In addition to cinchona alkaloid derivatives, a number of other catalysts were also developed recently for enantioselective halocyclizations using alcohols, [53] carboxamides, [54] sulfonamides, [55] carbamates, [56] and acetimidates [57] as the nucleophiles. An elegant enantioselective total synthesis of (À)-chimonanthine was recently realized by applying a chiral anionic phase-transfer catalyst promoted asymmetric bromocyclization of tryptamine derivatives using carbamates as the nucleophile.…”