Li-Xin Wang

A highly organocatalytic stereoselective double Michael reaction: efficient construction of optically enriched spirocyclic oxindoles

An effective double Michael reaction has been disclosed to access spirocyclic oxindoles in high yields (up to 98%) and excellent enantioselectivities (up to 98% ee).

Asymmetric Michael Addition of α-Substituted Isocyanoacetates with Maleimides Catalyzed by Chiral Tertiary Amine Thiourea

A highly diastereoselective and enantioselective Michael addition of α-substituted isocyanoacetates with maleimides catalyzed by bifunctional tertiary amine thioureas has been developed. Various chiral succinimide derivatives bearing adjacent quaternary and tertiary stereocenters were prepared in excellent yields (up to 98%), diastereoselectivities (up to 99:1), and enantioselectivities (up to 98% ee). The synthetic utility of chiral succinimide derivatives is also demonstrated in the preparation of h5-HT(1d) receptor agonist motifs.

Asymmetric Synthesis of 3,3′-Spirooxindoles Fused with Cyclobutanes through Organocatalytic Formal [2 + 2] Cycloadditions under H-Bond-Directing Dienamine Activation

The first organocatalytic asymmetric synthesis of a spirooxindole skeleton incorporated with a cyclobutane moiety has been successfully developed on the basis of H-bond-directing dienamine activation. Structurally complex spirocyclobutyl oxindoles, which possess four contiguous stereocenters, including one spiro quaternary center, were obtained in good yields (up to 83%) with excellent β,γ-regioselectivity (>19:1) and stereocontrol (up to >19:1 dr and 97% ee).

Enantioselective α-amination of branched aldehydes promoted by simple chiral primary amino acids.

A series of simple chiral primary amino acids were first successfully applied to promote the enantioselective α-amination of branched aldehydes with azadicarboxylates and the desired adducts bearing quaternary stereogenic centers were obtained in excellent yields (up to 99%) and enantioselectivities (up to 97% ee).

Highly enantioselective aldol reaction of acetone with β,γ-unsaturated α-keto esters promoted by simple chiral primary–tertiary diamine catalysts

A series of primary-tertiary diamine catalysts were successfully applied to promote the enantioselective aldol reaction of acetone with β,γ-unsaturated α-keto esters in excellent yields (up to 99%) and enantioselectivities (up to 96% ee).

Organocatalytic direct asymmetric vinylogous Mannich reaction of γ-butenolides with isatin-derived ketimines

The first direct asymmetric vinylogous Mannich reaction of γ-butenolides with isatin-derived ketimines has been effectively realized promoted by a bifunctional quinidine-derived catalyst. A series of chiral 3-aminooxindole derivatives bearing adjacent tertiary and quaternary stereocenters with the butenolide moiety were obtained in excellent yields (up to 97%) and high enantioselectivities (up to 96% ee).

Highly enantioselective direct vinylogous Michael addition of γ-substituted deconjugated butenolides to maleimides catalyzed by chiral squaramides

Highly enantioselective direct vinylogous Michael reactions of γ-aryl-substituted deconjugated butenolides with maleimides, catalyzed by only 1 mol% bifunctional squaramides derived from cinchona alkaloids, were achieved with excellent yields (up to 96%) and enantioselectivities (up to 97% ee). This protocol features a very low catalyst loading, mild reaction conditions and provides a potential and effective method for the construction of optically active chiral butenolides with adjacent quaternary and tertiary stereocenters.

Organocatalytic Asymmetric Annulation between Hydroxymaleimides and Nitrosoarenes: Stereoselective Preparation of Chiral Quaternary N-Hydroxyindolines

An unusual and highly effective asymmetric annulation of nitrosoarenes with hydroxymaleimides catalyzed by a chiral bifunctional amine squaramide catalyst has been disclosed. A wide range of highly fused chiral N-hydroxyindolines with two consecutive quaternary stereocenters and multifunctional groups were directly and effectively prepared in excellent yields (up to >99%) with complete regioselective cyclization and excellent stereoselectivities (up to >99:1 dr and >99% ee). The efficiency and potentials of the new reaction and the target chiral entities were well demonstrated by delicate transformations into a series of new chiral indolines.

Construction of Quaternary Stereocenters: Asymmetric α‐Amination of Branched Aldehydes Catalyzed by Monoimide Substituted Cyclohexane‐1,2‐Diamines

A highly efficient enantioselective α-amination of branched aldehydes catalyzed by chiral imide monosubstituted 1,2-diamine derivatives was reported to afford the quaternary stereogenic centers in excellent yields (up to 99%) and enantioselectivities (up to 97% ee). Chirality 25:668-672, 2013.

An efficient and enantioselective Michael addition of aromatic oximes to α,β‐unsaturated aldehydes promoted by a chiral diamine catalyst derived from α,α‐diphenyl prolinol

Chiral diamine catalysts 11a-e derived from α,α-diphenyl prolinol were prepared and successfully applied to the Michael addition of aromatic oximes to α,β-unsaturated aldehydes in mediocre to good yields (up to 78%) and good to high enantioselectivities (up to 93% ee).