De Wang

A Phosphine‐Catalyzed Novel Asymmetric [3+2] Cycloaddition of C,N‐Cyclic Azomethine Imines with δ‐Substituted Allenoates

Catalytic asymmetric [3+2] cycloadditions of C,N-cyclic azomethine imines with δ-substituted allenoates have been developed in the presence of (S)-Me-f-KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo- and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ-substituted allenoates have been applied as a δ,γ-C-C bond participated C2 synthon in asymmetric synthesis.

Highly Efficient and Stereoselective Construction of Bispirooxindole Derivatives via a Three‐Component 1,3‐Dipolar Cycloaddition Reaction

A highly regio- and stereoselective synthesis of bispirooxindoles by 1,3-dipolar cycloaddition of in situ generated azomethine ylides from isatin and proline to different electron-deficient alkenes has been developed. The synthesis affords the desired bispiro scaffold compounds in excellent yields with high regioselectivity under mild conditions. The stereochemistry was determined by single-crystal X-ray analysis.

Cu(I)-catalyzed asymmetric chlorination of β-keto esters in the presence of chiral phosphine-schiff base type ligands

Chiral phosphine-Schiff base type ligand L8 prepared from (R)-(-)-2-(diphenylphosphino)-1,1-binaphthyl-2-amine was found to be a fairly effective ligand for Cu(I)-promoted enantioselective chlorination of β-keto esters to give the corresponding products in high yields and with moderate enantioselectivities.

Facile synthesis of 2-pyrazolines and α,β-diamino ketones via regioselective ring-opening of hydrazone-tethered aziridines

A facile strategy to access 2-pyrazolines and α,β-diamino ketones via SN(2)-type ring-opening of N-(aziridin-2-ylethylidene)hydrazines or N-(aziridin-2-ylbutylidene)hydrazines in the presence of Lewis acid or trifluoromethanesulfonic acid (TfOH) is described in this context.