Tang-Lin Liu

Catalytic asymmetric 1,3-dipolar cycloaddition of N-unprotected 2-oxoindolin-3-ylidene derivatives and azomethine ylides for the construction of spirooxindole-pyrrolidines

Asymmetric 1,3-dipolar cycloaddition of N-unprotected 2-oxoindolin-3-ylidene with azomethine ylides for the construction of spirooxindole-pyrrolidines bearing four contiguous stereogenic centers has been achieved with AgOAc/TF-BiphamPhos complexes for the first time. This catalytic system performance well over a broad scope of substrates, providing the synthetically useful adducts in high yields and excellent diastereoselectivities and moderate enantioselectivities.

Stereoselective construction of a 5-aza-spiro[2,4]heptane motif via catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides and ethyl cyclopropylidene acetate.

A direct and facile synthesis of highly functional 5-aza-spiro[2,4]heptanes, a valuable structural motif for drug discovery, is developed via catalytic asymmetric 1,3-dipolar cycloaddition of cyclopropylidene acetate and azomethine ylides for the first time.

A Facile Access to Enantioenriched Isoindolines via One-Pot Sequential Cu(I)-Catalyzed Asymmetric 1,3-Dipolar Cycloaddition/Aromatization

Facile access to enantioenriched isoindolines bearing a quaternary stereogenic center and a tertiary stereogenic center was successfully developed via highly efficient Cu(I)/(S,Rp)-PPFOMe-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylide with quinone derivatives followed by silica-gel-promoted oxidation [corrected] in a one-pot reaction protocol. The present catalytic system exhibited high diastereoselectivity, excellent enantioselectivity, and a broad substrate scope under mild conditions.

Stereoselective Construction of Spiro(butyrolactonepyrrolidines) by Highly Efficient Copper(I)/TF‐BiphamPhos‐Catalyzed Asymmetric 1,3‐Dipolar Cycloaddition

Pyrrole into one: The catalytic asymmetric 1,3-dipolar cycloaddition of cyclic aldimino esters has been accomplished for the first time, enabling facile access to spiro(butyrolactonepyrrolidines) containing one spiro quaternary center and three tertiary stereogenic centers (see scheme). The catalytic system performs well with a broad range of substrates, furnishing synthetically useful adducts in high yields, with excellent diastereo- and enantioselectivities under mild conditions.

Highly Enantioselective Synthesis of Chiral Cyclic Allylic Amines via Rh-Catalyzed Asymmetric Hydrogenation

Highly regioselective and enantioselective asymmetric hydrogenation of cyclic dienamides catalyzed by an Rh-DuanPhos complex has been developed, which provides a readily accessible method for the synthesis of chiral cyclic allylic amines in excellent enantioselectivities (up to 99% ee). The products are valuable chiral building blocks and could be easily transformed to multisubstituted cyclohexane derivatives.

Catalytic asymmetric construction of spiro pyrrolidines with contiguous quaternary centers via 1,3-dipolar cycloaddition of azomethine ylides

Bioactive 5-aza-spiro[2,4]heptanes with high functionality and up to three contiguous all-carbon quaternary stereogenic centers were synthesized by Cu(I)-catalyzed asymmetric endo-selective 1,3-dipolar cycloaddition of azomethine ylides with cyclopropylidene acetates. This synthesis system performs well for a broad scope of substrates. α-unsubstituted/α-substituted azomethine ylides and cyclopropylidene acetates are compatible 1,3-dipoles and dipolarophiles, which afford the spiro heterocycles with contiguous quaternary centers at 2-, 3- and 4-positions of the pyrrolidine ring in good yield (up to 97%) and high diastereoselectivity (95:5–>98:2 d.r) and excellent enantioselectivity (87%–98% ee).

Catalytic Enantioselective Desymmetrization of Meso Cyclic Anhydrides via Iridium-Catalyzed Hydrogenation

A novel method to desymmetrize meso-anhydrides into lactones via asymmetric hydrogenation catalyzed by the Ir-C3*-TunePhos complex has been developed. Various chiral lactones were synthesized with full conversion and excellent enantioselectivity under high reaction temperature.