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An open-air palladium-catalyzed O-glycosylation was developed using glycals and arylboronic acids with base additives at ambient conditions. The novel approach enabled facile access to various

A new methodology of stereoselective C-glycosylation has been developed with 3,4-O-carbonate glycals and boronic acids, catalyzed by 1,2-bis(phenylsulfinyl)ethane palladium(II) acetate under open-air conditions at room temperature. This mild method is simple in operation, wide in substrate range, and tolerant in alcoholic/phenolic hydroxyl and amino groups. High to excellent yields were observed for all substrates tested, with the driving force mainly contributed by decarboxylation. Meanwhile, the high 1,4-trans-selectivity was achieved by steric effects as proposed.

A novel gold-catalyzed C-glycosylation has been developed to gain access to α,(Z)-selective C-vinyl glycosides, starting from readily available glycals and propargylic carboxylate. This reaction involves a tandem intermolecular gold-catalyzed 1,3-acyloxy migration/Ferrier rearrangement with the involvement of allenic ester as the glycosyl acceptor. A wide range of substrate scope with good to excellent yields was achieved with complete diastereoselectivity. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version We thank the Ministry of Education (MOE 2013-T3-1-002), National Research Foundation (NRF2016NRF-NSFC002-005), Nanyang Technological University, Singapore (RG14/16), China Scholarship Council (No. 201508420062), and Youth Talent Development Foundation of China Three Gorges University for their financial support. Dr. Yongxin Li and Dr. Ganguly Rakesh in the division of chemistry and biological chemistry, Nanyang Technological University are also acknowl-edged for X-ray analysis.

we first report the application of 3-acyl-5-hydroxybenzofurans as a scaffold to develop potential drugs for breast cancer. seven novel derivative compounds were synthesized by using a microwave-assisted synthesis method. those compounds exhibited different antiproliferation against human breast cancer mcf-7 cells, with the best activity of ic50=43.08 mu m for compound 1. a quantum mechanics polarized ligand docking (qpld) study was carried out to investigate the binding interactions between these compounds and estrogen receptor alpha (er alpha). the simulation results showed that the trend of receptor-ligand binding interactions was same as that of their antiproliferative activities. a detailed analysis indicated that compound 1 possesses the highest van der waals and hydrogen bond interactions compared to the other six compounds and better inhibitors are achievable by enhancing the hydrogen bond interactions. based on these results, we addressed that 3-acyl-5-hydroxybenzofuran is an attractive scaffold for designing drugs against breast cancer. (c) 2013 elsevier ltd. all rights reserved.

A highly solid-emissive Boron–Fluorine scaffold with two conjugated alkyne groups ( BOPIM-S ) is facilely synthesized, which shows enhanced fluorescent intensity compared to the BOPIM dye without alkyne units. According to X-ray single crystal analysis, the terminal alkyne groups interact with atoms B, F, C and N on neighbouring molecules, producing a rigid rectangular structure, which helps to avoid energy loss via non-irradiative decay. Furthermore, BOPIM-S can undergo copper catalysed alkyne–azide-cycloaddition (CuAAC) chemistry with aromatic azides to produce conjugated molecules with high yields. According to absorption and fluorescent measurements, all these compounds synthesized by CuAAC emit large Stokes shift (over 100 nm) both in solution and in solid state. But the electronic environments of terminal aromatic rings slightly affect their photophysical properties.

Two new thiazole and thiadiazole alkaloids, penicilliumthiamine A and B (2 and 3), were isolated from the culture broth of Penicillium oxalicum, a fungus found in Acrida cinerea. Their structures were elucidated mainly by spectroscopic analysis, total synthesis and X-ray crystallographic analysis. Biological evaluations indicated that compound 1, 3a and 3 exhibit potent cytotoxicity against different cancer cell lines through inhibiting the phosphorylation of AKT/PKB (Ser 473), one of important cancer drugs target.

To develop more effective antitumor steroidal drugs, we synthesized a library including twenty-two novel cytotoxic 2-alkyloxyl substituted (25R)-spirostan-1,4,6-triene-3-ones and corresponding 1,2,3-triazoles through an abnormal monoepoxide ring-opening/elimination and 'click' reactions. After the cytotoxic evaluations against HepG2, Caski and HeLa cell lines, three steroidal triazoles 5b, 5f and 5m in this library were found to possess potent anti-proliferative effects against Caski cells with the half-inhibitory concentrations (IC50) of 9.4-11.8 mu M. The high-efficient and straightforward process was attractive feature for facile preparation of anti-tumor steroidal triazoles. (C) 2015 Elsevier Ltd. All rights reserved.

Three new furostanol saponins (1-3), including a polyhydroxyl saponin, were isolated from the rhizomes of Tupistra chinensis. The structures of these compounds were identified by NMR, MS spectral data and chemical methods.

Two new spirostanols and a new furostanol, reinocarnoside A (1), B (2) and C (3), were isolated from the roots of Reineckia carnea, together with two known compounds, (25S)-1β,3β,4β-trihydroxyspirostan-5β-yl-O-β-D-glucopyranoside (4), kitigenin-5β-O-β-D-glucopyranoside (5). The structures of three new compounds were elucidated by spectroscopic methods including 1-D NMR, 2-D NMR and MS spectrums, and their anticancer activities were evaluated by MTT method.