Learn More
This study aimed to isolate active compounds from traditional Chinese medicinal Taxillus sutchuenensis to inhibit hepatitis C virus (HCV) NS3 protease activity. Under the guidance of bioassay, 10 compounds were isolated from the EtOAc extract fraction, which were identified as inhibitors of HCV NS3 protease. IC50 values of these compounds were obtained, and(More)
A pincer-Pd complex was utilized in the chemoselective transfer hydrogenation of α,β-unsaturated ketones using n-BuOH as a hydrogen source and solvent. Good to excellent yields were obtained for various substrates even with reducible groups. Based on deuterium-labeling experiments, the reaction mechanism is proposed to occur via a pincer-Pd-hydride(More)
We report the novel chalcone-benzoxaborole hybrids and their structure-activity relationship against Trypanosoma brucei parasites. The 4-NH(2) derivative 29 and 3-OMe derivative 43 were found to have excellent potency. The synergistic 4-NH(2)-3-OMe compound 49 showed an IC(50) of 0.010 μg/mL and resulted in 100% survival and zero parasitemia in a murine(More)
Allylic alcohols were directly used in Pd-catalyzed allylic alkylations of simple ketones under mild reaction conditions. The reaction proceeded smoothly at 20 °C by the concerted action of a Pd catalyst, a pyrrolidine co-catalyst, and a hydrogen-bonding solvent, and does not require any additional reagents. A computational study suggested that methanol(More)
An asymmetric domino reaction was developed utilizing readily available cyclic N-sulfonylimines and simple aldehydes to construct biologically important and synthetically challenging piperidine derivatives consisting of three contiguous stereocenters. trans-Perhydroindolic acid proved to be an efficient organocatalyst in this reaction (up to 89% yield,(More)
C-O bond cleavage of allylic alkyl ether was realized in a Pd-catalyzed hydrogen-bond-activated allylic alkylation using only alcohol solvents. This procedure does not require any additives and proceeds with high regioselectivity. The applicability of this transformation to a variety of functionalized allylic ether substrates was also investigated.(More)
Perhydroindolic acids, the by-products obtained in the industrial production of a trandolapril intermediate, were used as chiral organocatalysts in asymmetric Michael addition reactions of aldehydes to nitroolefins. These proline-like catalysts are unique for their rigid bicyclic structure with two H atoms attached to the bridgehead C atoms lying on the(More)
Catalyzed by a rhodium complex of P-stereogenic diphosphine ligand (R)-2-tert-butylmethylphosphino-3-(di-tert-butylphosphino)quinoxaline ((R)-3H-QuinoxP*), five-membered cyclic α-dehydroamino ketones bearing endocyclic vinyl and endocyclic keto-carbonyl groups were sequentially hydrogenated to give chiral cyclic trans-β-amino alcohols with two contiguous(More)
An asymmetric domino reaction was developed utilizing readily available cyclic α-dehydroamino ketones and aldehydes, which when subjected a 2-iodoxybenzoic acid (IBX)-mediated oxidation gives pyrrolidinone-containing tricyclic derivatives. trans-Perhydroindolic acid proved to be an efficient organocatalyst in this reaction (up to 94% yield, 99% ee, and(More)
Palladium-catalyzed asymmetric allylic alkylation of ketones, via enamines generated in situ as nucleophiles, were carried out smoothly with chiral metallocene-based P,N-ligands. Under the same conditions, however, reactions of aldehydes could hardly be observed. Subsequently, this obstacle was resolved by using chiral metallocene-based P,P-ligands. Both(More)