Xin-Yan Wu

Organocatalyzed Enantioselective Mannich Reaction of Pyrazoleamides with Isatin-Derived Ketimines

The first organocatalytic enantioselective Mannich reaction of pyrazoleamides with isatin-derived N-Boc ketimines has been developed to afford 2-oxindole-based chiral β-amino amides in good yields (84-97%) with excellent diastereo- and enantioselectivities (up to 99:1 dr and >99% ee).

Construction of Benzo[c]carbazoles and Their Antitumor Derivatives through the Diels–Alder Reaction of 2-Alkenylindoles and Arynes

The direct assembly of benzo[c]carbazole derivatives via the Diels-Alder reaction of arynes and easily accessible 2-alkenylidoles was reported. By employing different aryne precursor loads, 6,7-dihydrobenzo[c]carbazoles or aryl-substituted 7,11b-dihydrobenzo[c]carbazoles could be controllably generated in good to excellent yields under a nitrogen atmosphere. On the other hand, when the reaction was conducted under oxygen, oxidated/aromatized product benzo[c]carbazoles could be generated directly with high selectivity and efficiency in a one-step manner. Interestingly, the benzo[c]carbazole-5-carboxamide amidation derivatives of the above products showed good antitumor activities. The inhibitory effect of these molecules against cancer cells was also described.

Asymmetric hydroarylation of norbornene derivatives catalyzed by palladium complexes of chiral quinolinyl-oxazolines

Abstract Chiral quinolinyl-oxazolines were found to be efficient ligands in the enantioselective palladium-catalyzed Heck-type hydroarylation of norbornene and its derivatives. The ligands with a medium sized alkyl group on the oxazoline ring provided higher enantioselectivities. The presence of electron-donating substituents on the aryl iodide increased the selectivity and the yield of the reactions. The configuration of (−)-exo-2-phenylbicyclo[2.2.1]heptane has been assigned as (1R,2R).

Chiral 1,2,3,4-tetrahydroquinolinyl-oxazoline ligands for Ru-catalyzed asymmetric transfer hydrogenation of ketones

Abstract Chiral 1,2,3,4-tetrahydroquinolinyl-oxazoline compounds have been synthesized from 8-quinolinecarboxylic acid and enantiomerically pure amino alcohols using a convenient procedure. Asymmetric transfer hydrogenation of aryl ketones with the catalyst prepared in situ from [Ru( p -cymene)Cl 2 ] 2 and ligands 2 in 2-propanol in the presence of KOH, afforded the corresponding secondary alcohols in reasonable yields and up to 83% e.e.

Enantioselective Heck-type hydroarylation of norbornene with phenyl iodide catalyzed by palladium/quinolinyl-oxazolines

Abstract Enantioselective Heck-type hydroarylation of norbornene with phenyl iodide catalyzed by the palladium complex of quinolinyl-oxazolines is described. Using DMSO as the solvent and HCOOH/Et 3 N as the hydride source, exo -2-phenybicyclo[2.2.1]heptane is produced in reasonable yields and up to 74% ee.

Chiral quinolinyl-oxazolines as ligands for copper(I)-catalyzed asymmetric cyclopropanation

Abstract Chiral quinolinyl-oxazoline compounds have been synthesized from enantiomerically pure amino alcohols and 8-quinoline-carboxylic acid using a convenient procedure. Asymmetric cyclopropanation of styrene with diazoacetates in the presence of 1 mol% of CuOTf and quinolinyl-oxazolines gave 2-phenylcyclopropane carboxylates in moderate enantiomeric excesses.

Enantioselective Synthesis of 3-Alkynyl-3-hydroxyindolin-2-ones by Copper-Catalyzed Asymmetric Addition of Terminal Alkynes to Isatins

A highly efficient copper-catalyzed asymmetric addition of terminal alkynes to isatins has been developed. In the presence of a catalytic amount of copper iodide and a chiral phosphine ligand, the reaction gave the corresponding chiral 3-alkynyl-3-hydroxyindolin-2-ones in high yields with high enantioselectivity. This methodology has a broad substrate scope, and the synthetic utility of the present protocol was further demonstrated by the transformation of chiral alkynylation products.

Chiral pyridinyl-oxazolines as ligands for copper(I)-catalyzed asymmetric cyclopropanation

New chiral ligands containing oxazoline unit and pyridine separated by a methylene group 3 have been synthesized from enantiomerically pure amino alcohols and 2-picoline using a convenient procedure. Comparative investigation of ligands 3 with chiral conjugate pyridinyl-oxazoline ligands 2 and quinolinyl-oxazoline ligands 1 in copper(I)-catalyzed asymmetric cyclopropanation of styrene with diazoacetates was described.

Highly enantioselective direct allylic alkylation of butenolides with Morita–Baylis–Hillman carbonates catalyzed by chiral squaramide-phosphine

An efficient asymmetric vinylogous allylic alkylation of β,γ-butenolides with Morita–Baylis–Hillman carbonates has been developed. With a chiral cyclohexane-based squaramide-phosphine catalyst 5e, optically active γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary chiral centers have been constructed in good-to-excellent yields (up to 98%) and excellent stereoselectivities (87 : 13–99 : 1 dr, 96–99% ee).

Pd(0)-catalyzed benzylation of indole through η3-benzyl palladium intermediate

Abstract An efficient method has been developed for the Pd(0)-catalyzed benzylation of indoles, which occurred with exclusive regioselectivity. When this reaction was performed in the presence of Pd(PPh3)4, it provided access to a broad range of substituted indoles bearing diarylmethanes at their 3-position in 90%–99% yields under mild conditions.