Palladium Catalyzed Annulation of o-Iodo-Anilines with Propargyl Alcohols: Synthesis of Substituted Quinolines.

A palladium catalyzed annulation of o-iodo-anilines with propargyl alcohols for the synthesis of substituted quinolines has been developed. The reaction tolerates diverse functional groups under mild conditions, providing direct access to 2,4-disubstituted quinolines from easily available starting materials. A broad range of 2,4-disubstituted quinolines were efficiently prepared in good to excellent yields.

[A new xanthone from Hypericum lagarocladum].

Repeated silica gel column chromatography, reversed-phase C_(18) column chromatography, Sephadex LH-20 column chromatography, high performance liquid chromatography and semi-preparative medium pressure liquid chromatography were performed to separate and purify the chemical constituents of Hypericum lagarocladum. Spectroscopic methods such as mass spectrometry(MS) and nuclear magnetic resonance(NMR) combined with physicochemical properties were adopted in identifying the structure of the isolated compounds. Ten compounds were isolated from the ethyl acetate fraction of H. lagarocladum and identified as lagarxanthone A(1), 1,7-dihydroxyxanthone(2), 3,4,5-trihydroxyxanthone(3), 2,7-dihydroxy-1-methoxyxanthone(4), 1,3-dihydroxy-7-methoxyxanthone(5), 1,5-dihydroxy-8-methoxyxanthone(6), 3,4-dihydroxy-2-methoxyxanthone(7), 3,4-dihydroxy-5-methoxyxanthone(8), 2,3-dimethoxyxanthone(9), and 2,3,4-trimethoxyxanthone(10). Among them, compound 1 was a new compound, and compounds 2-10 were isolated from this plant for the first time. These ten compounds were tested for glucose uptake in L6 cells, and the results showed that all the compounds had no significant effect on glucose uptake.

Penpolonin A-E, cytotoxic α-pyrone derivatives from Penicillium polonicum.

Five new α-pyrone derivatives, named penpolonin A-E (1-5), together with two known compounds (6-7) were acquired from the endophytic fungus Penicillium polonicum isolated from the roots of Camptotheca acuminata Decne. Their structures were established by combination of NMR and HRESIMS data and the absolute configurations of 1-5 were determined by NMR calculations and comparison of experimental and calculated ECD data. Compounds 3 and 7 exhibited moderate cytotoxicity against Hep-2, TU212 human laryngeal cancer cells with IC50 values ranging from 31.6 to 45.1 µg/ml, compound 4 showed weak cytotoxicity against the Hep-2 and TU212 cell lines with IC50 values of 69.2 and 68.7 µg/ml.

Molybdenum-Mediated Reductive Hydroamination of Vinylcyclopropanes with Nitroarenes: Synthesis of Homoallylamines.

A molybdenum-mediated reductive hydroamination of vinylcyclopropanes with nitroarenes has been developed. A broad range of substituted homoallylamines were prepared in good to excellent yields from readily available starting materials. No noble metal catalysts were used in this reaction, and Mo(CO)6 acted as both catalyst and reductant. This protocol provides an effective method for the selective synthesis of substituted homoallylamines from easily available nitroarenes.

Four new polycyclic polyprenylated acylphloroglucinols from Hypericum wilsonii and their glucose uptake bioactivities.

Wilsonglucinols H-K (1-4), four new polycyclic polyprenylated acylphloroglucinols (PPAPs), and eight known compounds (5-12) were isolated and identified from the aerial parts of Hypericum wilsonii. Their planner structures were confirmed via extensive NMR and HRESIMS data analysis. The absolute configurations of the new compounds were mainly determined by NMR calculation and electronic circular dichroism (ECD) calculation. Compounds 1, 6, 8, and 10 showed glucose uptake activities at 30 µg/mL, in which compound 6 showed the strongest effect and increased the glucose uptake by 2.73 folds.

Copper-catalyzed 1,2-Borylacylation of 1,3-Enynes: synthesis of ß-Alkynyl ketones.

A copper catalyzed 1,2-borylacylation of 1,3-enynes with B2pin2 and acid chlorides has been developed. Using readily available 1,3-enynes, B2pin2 and acid chlorides as substrates, a range of highly functionalized α,α-disubstituted ß-alkynyl ketones were readily prepared under mild conditions in moderate to good yields. The borylacylated products can be easily derivatized to give several valuable structures. Notably, treatment of the products with NaBO3·4H2O provided 1,2-allenyl ketones, which is proposed to proceed via a retro-aldol process of the corresponding homopropargyl alcohols.

New Polyprenylated Acylphloroglucinol Derivatives and Xanthones From Hypericum wilsonii.

Four new polyprenylated acylphloroglucinol derivatives, hyperwilone A-D (1-4), and two new xanthones, wilsonxanthone A (5) and wilsonxanthone B (6), together with eight known compounds were isolated from the aerial parts of Hypericum wilsonii. Their structures were expounded by comprehensive analysis of the 1D and 2D NMR spectra and HRESIMS. The relative configurations and absolute configurations of 1-6 were determined by NMR calculations and comparing their experimental and computed ECD data. All compounds were evaluated for GLUT4 translocation effects in L6 myotubes. Compound 5 showed the strongest GLUT4 translocation effects with 2.57 folds at a concentration of 30 µg/ml.