Yangang Liu

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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)
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)
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)
Via a strategy of asymmetric reductive desymmetrization, chiral cis-epoxy naphthoquinols with multiple contiguous stereocenters and functional groups were synthesized with excellent enantioselectivities (96-99% ee) and diastereoselectivities (8/1-15/1). A combined asymmetric hydrogenation/transfer hydrogenation mechanism was proposed based on experimental(More)
A Pd-catalyzed asymmetric allylic substitution with 1,3-dithianes as acyl anion equivalents has been developed in high yields and excellent enantioselectivities. The reaction was performed on a gram scale, and the corresponding alkylated products were conveniently converted into several biologically active products. This work provides an alternative(More)
A highly enantioselective Pd-catalyzed asymmetric allylic substitution cascade of cyclic N-sulfonylimines with an accompanying asymmetric desymmetrization has been developed for the construction of fused tetrahydroindole derivatives bearing two chiral centers. Mechanistic studies confirmed that the cascade reaction proceeds by initial allylic alkylation and(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)
Asymmetric hydrogenations of a series of β-amino ketones were carried out with a bimetallic complex (RuPHOX-Ru) as the chiral catalyst. Almost all the reactions (performed in a mixed solvent system of toluene and H2O in the presence of KOH) gave quantitative conversions into their respective products with up to 99.9% ee. The RuPHOX-Ru catalyst is stable to(More)
An iridium-catalyzed asymmetric hydrogenation of unfunctionalized exocyclic C=C bonds was performed by using an axially flexible chiral phosphine-oxazoline ligand, providing the desired chiral 1-benzyl-2,3-dihydro-1H-indene products with up to 98 % ee (enantiomeric excess). This represents the first general hydrogenation of unfunctionalized exocyclic(More)