Wenzhong Huang

Silver-Catalyzed Radical Arylphosphorylation of Unactivated Alkenes: Synthesis of 3-Phosphonoalkyl Indolines

A silver-catalyzed phosphorylation/cyclization cascade of N-allyl anilines was developed, allowing direct access to 3-phosphonoalkyl indolines, which were previously obtainable only via tedious procedures under harsh/toxic conditions. The unactivated double bond serves as the radical acceptor, whereas H-phosphonates or -phosphine oxides act as the radical precursor. This protocol features simple operation, broad substrate scope, and great exo selectivity, and a gram-scale synthesis could be readily carried out.

Butyrolactones derivatives from the fermentation products of a plant entophytic fungus Penicillium oxalicum

Two new butyrolactone derivatives, terrelactones A and B (1 and 2), together with four known butyrolactone derivatives (3–6), were isolated from the fermentation products of the fungus Penicillium oxalicum 0403. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of 1 and 2 were evaluated. The results showed that compounds 1 and 2 exhibited high anti-TMV activity with inhibition rates of 25.5% and 27.4%, respectively. The inhibition rate is close to that of positive control (28.9%).

Catalyst-free synthesis of 3-(1-arylsulfonylalkyl)indoles via three-component reaction of indoles, carbonyls, and arenesulfinic acids

ABSTRACT A catalyst-free three-component reaction of indoles, carbonyls, and arenesulfinic acids performed at room temperature provides direct access to biologically important 3-(1-arylsulfonylalkyl)indoles. This process features mild conditions, low cost, broad substrate scope, and high yields, and mechanistically bis(indolyl)methanes were identified as the key intermediates. GRAPHICAL ABSTRACT

Isolation of Xanthones from the Fermentation Products of the Endophytic Fungus of Phomopsis amygdali

Two new xanthones, 4,5-dihydroxy-3-(2-hydroxyethyl)-1-methoxy-8-methoxycarbonylxanthone (1) and 1,8-dihydroxy-4-(2-hydroxyethyl)-3-methoxyxanthone (2), and seven known xanthones (3–9) were isolated from the fermentation products of a Phomopsis species fungus. Compounds 1, 2, and 7 were tested for their cytotoxicity against five human tumor cell lines. Compound 1 showed cytotoxicity against A549 and PC3 cells with IC50 values of 2.6 and 2.4 μM, respectively. The other compounds also showed moderate cytotoxicity for some tested cell lines with IC50 values between 5.2–9.2 μM.

Three-Component Reactions of Ketene Dithioacetals, Aldehydes, and Arenesulfinic Acids: Facile Synthesis of Allylic Sulfones

Abstract A facile and efficient synthesis of allylic sulfones via sulfuric acid–mediated three-component reactions of easily available ketene dithioacetals, aldehydes, and arenesulfinic acids is presented. The reaction features low cost and good yields. GRAPHICAL ABSTRACT

Two new phenolic constituents from Clematis connata DC.

Two new phenolic compounds, 3,4-dihydroxyphenethyl 5-hydroxy-4-oxopentanoate (1) and 3-(4-hydroxy-2,5-dimethoxyphenyl)-3-oxopropyl acetate (2), together with fifteen known compounds, 3 to 17, were isolated from the dried whole plants of Clematis connata DC. Their structures were elucidated by extensive spectral analysis, especially 2D NMR techniques. Compounds 1 to 5 were evaluated for their in vitro cytotoxicities against acute promyelocytic leukemia HL-60, hepatocellular carcinoma Hep-G2, oropharyngeal epidermoid carcinoma KB and breast cancer cells MDA-MB-231. Compounds 1 and 3 exhibited the most potential with IC50 values of 0.63 and 1.27 mu M against MDA-MB-231 and HepG2, respectively. The antibacterial activities experiment of all the isolated compounds showed that only Compounds 3 to 5 exhibited weak activities against Staphylococcus aureus, methcillin-resistant S. aureus and beta-lactamase positive S. aureus, and Compound 9 and 17 showed weak activities against S. aureus.

Two new biphenyls from the stems of Garcinia tetralata

Abstract Two new biphenyls (1 and 2) and three known xanthones (3–5) were isolated from the ethanol extract of the stems of Garcinia tetralata. Structural elucidations of 1–2 were elucidated by spectroscopic methods including extensive 1D- and 2D-nuclear magnetic resonance spectroscopy techniques. Compounds 1–2 showed anti-rotavirus activities with SI above 10.

Br2- or HBr-catalyzed synthesis of asymmetric 3,3-di(indolyl)indolin-2-ones

Abstract Under the catalysis of 1 mol% of Br2 or HBr at room temperature, indoles undergo a rapid reaction with 3-hydroxy-3-(indol-3-yl)indolin-2-ones to give asymmetric 3,3-di(indol-3-yl)indolin-2-ones with high efficiency and wide substrate scope. This is a rare example of Br2 acting as a Lewis acid catalyst. Theoretical calculations suggest that both the catalytic activity of the catalysts and the stability of reaction intermediates are responsible for the high efficiency of this reaction.