Shu-Wen Duan

An organocatalytic Michael-aldol cascade: formal [3+2] annulation to construct enantioenriched spirocyclic oxindole derivatives

An efficient organocatalytic Michael-aldol cascade reaction for the asymmetric synthesis of spirocyclic oxindole derivatives fused with tetrahydrothiophenes has been developed through a formal [3+2] annulation strategy.

Enantioselective Michael Reactions of β, β-Disubstituted Nitroalkenes: A New Approach to β2,2-Amino Acids with Hetero-Quaternary Stereocenters

An atom-economic organocatalytic asymmetric Michael reaction of alpha,beta,beta-trisubstituted olefins has been successfully developed. The reaction exhibits excellent enantioselectivities under low loading of catalysts, and the conjugate addition products are valuable for the synthesis of novel beta(2,2)-amino acids and beta-peptides.

Room temperature synthesis of isoquino[2,1-a][3,1]oxazine and isoquino[2,1-a]pyrimidine derivatives via visible light photoredox catalysis

A novel and efficient construction of isoquino[2,1-a][3,1]oxazine and isoquino[2,1-a]pyrimidine frameworks has been realized by means of visible light photocatalytic reactions using air as the oxidant at room temperature. This strategy offers a direct and rapid access to two kinds of biologically important fused heterocycles in good to excellent yields.

Facile synthesis of enantioenriched Cγ-tetrasubstituted α-amino acid derivatives via an asymmetric nucleophilic addition/protonation cascade.

An asymmetric nucleophilic addition/protonation reaction of 3-substituted oxindoles and ethyl 2-phthalimidoacrylate has been described. This strategy can give direct access to C(γ)-tetrasubstituted α-amino acid derivatives bearing 1,3-nonadjacent stereocenters with up to 98% yield, 94:6 dr, and >99% ee. Dual activation is proposed in the transition state, and the opposite enantiomers can be obtained simply by changing cinchonidine-derived catalyst to the cinchonine analogue.

Enantioselective Conjugate Addition of Oximes to Trisubstituted β-Nitroacrylates: An Organocatalytic Approach to β2,2-Amino Acid Derivatives

A highly enantioselective organocatalytic intermolecular conjugate addition of oximes to β-nitroacrylates has been developed. The highly functionalized adducts obtained are valuable precursors for asymmetric synthesis, as demonstrated by the synthesis of β(2,2)-amino acids and oxazolidin-2-ones.

Aerobic oxidative C–B bond cleavage of arylboronic acids mediated by methylhydrazines

The aerobic oxidative C–B bond cleavage and ipso-hydroxylation of arylboronic acids mediated by methylhydrazine have been developed under metal-free conditions. This transformation affords structurally diverse phenols in good to excellent yields (26 examples, 71–99%).

Organocatalytic Conjugate Additions of Acetylacetone to 3-Ylideneoxindoles: A Direct Access to Highly Enantioenriched Oxindole Derivatives

A highly enantioselective organocatalytic conjugate addition of acetylacetone to 3-ylideneoxindoles is described. This method provides polysubstituted oxindoles in good to excellent enantioselectivities and high isolated yields.