SPINOL-derived Phosphoric Acid Research Articles

Enantioselective 1,1-diarylation of terminal alkenes catalyzed by palladium with a chiral phosphoric acid

The enantioselective 1,1-diarylation of allyl sulfones and vinyl sulfones is reported for the first time, enabled by a combination of Pd2dba3 and a chiral SPINOL-derived phosphoric acid. Various chiral sulfones containing 1,1-diarylalkane motifs were obtained in moderate to good yields with moderate to high enantioselectivities. Control experiments suggested that the sulfone group plays a key role in providing enantioselectivity and reactivity control and might serve as a directing group.

Chiral Phosphoric Acid-Catalyzed Enantioselective Construction of 2,3-Disubstituted Indolines.

Highly enantio- and regioselective (3 + 2) formal cycloaddition of β-substituted ene- and thioenecarbamates as well as cyclic enamides with quinone diimides catalyzed by a BINOL- and SPINOL-derived phosphoric acid is reported. A wide variety of 2,3-disubstituted 2-aminoindolines, including polycyclic ones, were prepared in generally high yields (up to 98%) with moderate to complete diastereoselectivities and in most cases excellent enantioselectivities (up to 99% ee).

Catalytic Asymmetric 1,4-Reduction of α-Branched 2-Vinyl-azaarenes by a Chiral SPINOL-Derived Borophosphate

The catalytic asymmetric 1,4-reduction of α-branched 2-vinylazaarenes by a SPINOL-derived borophosphate has been realized. A SPINOL-derived phosphoric acid is used to form a bifunctional phosphoryl...

Enantioselective three-component Ugi reaction catalyzed by chiral phosphoric acid

A catalytic enantioselective three-component Ugi reaction was developed. SPINOL-derived phosphoric acid with bulky 2,4,6-tricyclohexylphenyl groups at the 6,6′ positions was found to be the best catalyst to afford α-amino amide derivatives in good to excellent yields (62% to 99%) and enantiocontrol (81% to >99% enantiomeric excess). This asymmetric reaction was applicable well to an array of aliphatic aldehydes. The gram-scale synthesis, modification of dapsone, and enantioselective synthesis of ( R )-Lacosamide underline the general utility of this methodology. Influence of dihedral angles and substituents of the chiral phosphoric acids on the enantioselectivity was also discussed in this article.

Asymmetric hydrogenolysis of racemic 3-substitued-3-hydroxy-isoindolin-1-ones employing SPINOL-derived chiral phosphoric acid

The asymmetric hydrogenolysis of racemic 3-substitued-3-hydroxyisoindolin-1-ones has been developed employing SPINOL-derived phosphoric acid and a high steric demand Hantzsch ester as the hydrogen source. The corresponding products are obtained in good yields and up to 93% enantioselectivities.

Inside Cover: Asymmetric Catalysis on the Nanoscale: The Organocatalytic Approach to Helicenes (Angew. Chem. Int. Ed. 20/2014)

The asymmetric synthesis of helicenes by a Fischer indolization catalyzed by a SPINOL-derived phosphoric acid is reported by B. List et al. in their Communication on page 5202 ff. The catalyst is designed for long-range control and bears extended π-surfaces at the 3,3′-position. It creates a chiral nanometer-sized pocket, which enables π–π stacking interactions between the substituents and the reactive intermediate. A variety of (di)azahelicenes were obtained with good to excellent yields and enentioselectivities.

Asymmetric catalysis on the nanoscale: the organocatalytic approach to helicenes.

The first asymmetric organocatalytic synthesis of helicenes is reported. A novel SPINOL-derived phosphoric acid, bearing extended π-substituents, catalyzes the asymmetric synthesis of helicenes through an enantioselective Fischer indole reaction. A variety of azahelicenes and diazahelicenes could be obtained with good to excellent yields and enantioselectivities.