A TEMPO promoted tandem reaction of 2-aminobenzophenones and benzylamines under electrochemical conditions.

This study describes the efficient synthesis of quinazolines promoted by TEMPO via electro-catalysis with 2-aminobenzophenones and benzylamines. The method exhibited remarkable chemoselectivity under mild reaction conditions. A series of quinazolines could be obtained in moderate to good yields. In addition, control experiments were carried out to verify the reaction mechanism. Furthermore, the synthesis on the gram scale was conducted successfully to give the target product.

Au-Catalyzed Intermolecular [2+2] Cycloadditions between Chloroalkynes and Unactivated Alkenes.

The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.

Iodine-catalyzed direct C-H thiolation of imidazo[1,5-a]quinolines for the synthesis of 3-sulfenylimidazo[1,5-a]quinolines.

An iodine-catalyzed regioselective sulfenylation of imidazo[1,5-a]quinolines was developed under metal- and oxidant-free reaction conditions. Using disulfides or thiophenols as sulfenylating agents, 3-sulfenylimidazo[1,5-a]quinoline derivatives were obtained in good to excellent yields with broad functional group tolerance. A multi-component reaction to generate 1-sulfenylated imidazo[1,5-a]pyridines is also described. Preliminary biological evaluation showed that some of the 3-sulfenylated imidazo[1,5-a]quinolines had significant anticancer activity.

Copper-Promoted Double Oxidative C-H Amination Cascade for the Synthesis of Imidazo[1,5-a]quinolines.

A copper-promoted cascade reaction of 2-methylazaarenes and benzylamines has been developed via sequential double oxidative C(sp(3))-H aminations. This protocol provides straightforward access to imidazo[1,5-a]quinoline derivatives without employing prefunctionalized substrates.

Synthesis, biological evaluation and molecular docking of calix[4]arene-based ß-diketo derivatives as HIV-1 integrase inhibitors.

In this publication, we design and report the synthesis of calix[4]arene-based ß-diketo derivatives as novel HIV-1 integrase (IN) inhibitors. The target compounds were obtained using Claisen condensation, and their structures were characterized by NMR and ESI-MS. Preliminary bioassays showed that calix[4]arene-based ß-diketo derivatives inhibit strand transfer (ST) with IC50 values between 5.9 and 21.2 µM. Docking studies revealed the predominant binding modes that were distinct from the binding modes of raltegravir, which suggests a novel binding region in the IN active site. Moreover, these compounds are predicted not to interact with some of the key amino acids (GLN148 and ASN155) implicated in viral resistance. Therefore, this series of compounds can further be investigated for a possible chemotype to circumvent resistance to clinical HIV-1 IN inhibitors.

Design and synthesis of novel ß-diketo derivatives as HIV-1 integrase inhibitors.

A series of novel ß-diketo derivatives which combined the virtues of 1,3-diketo, 1,2,3-triazole and polyhydroxylated aromatics moieties, were designed and synthesized as potential HIV-1 integrase (IN) inhibitors and evaluated their inhibition to the strand transfer process of HIV-1 integrase. The result indicates that 3,4,5-trihydroxylated aromatic derivatives exhibit good inhibition to HIV-1 integrase, but dihydroxylated aromatic derivatives and corresponding methoxy aromatic derivatives appear little inhibition to HIV-1 integrase.

Design, practical synthesis, and biological evaluation of novel 6-(pyrazolylmethyl)-4-quinoline-3-carboxylic acid derivatives as HIV-1 integrase inhibitors.

A series of novel 6-(pyrazolylmethyl)-4-oxo-4-quinoline-3-carboxylic acid derivatives bearing different substituents on the N-position of quinoline ring were designed and synthesized as potential HIV-1 integrase (IN) inhibitors, based on the structurally related GS-9137 scaffold. The structures of all new compounds were confirmed by 1H-NMR, 13C-NMR and ESI (or HRMS) spectra. Detailed synthetic protocols and the anti-IN activity studies are also presented.

Simultaneous removal of methylene blue and Pb2+ from aqueous solution by adsorption on facile modified lignosulfonate.

In this paper, simultaneous removal of methylene blue (MB) and Pb2+ from the binary component system by an easily prepared cross-linked lignosulfonate bio-adsorbent (CLLS) was described. CLLS was characterized by FTIR, SEM/EDS and TGA. The influences of pH, temperature, contact time and initial MB and Pb2+ concentrations on the adsorption performance were investigated. The results demonstrated a good ability of CLLS to remove MB and Pb2+ simultaneously. Using of 1.0 g L-1 loading, removal efficiency of MB and Pb2+ reached 98.0% and 97.8%, respectively, in the MB (100 mg.L-1)-Pb2+ (50 mg.L-1) system. Moreover, the adsorption isotherms and adsorption kinetics indicated that the results were fitting well with the Langmuir and pseudo-second-order model, respectively, for both MB and Pb2+. Based on the Langmuir model, the maximum adsorption capacity of MB and Pb2+ reached 132.6 and 64.9 mg g-1, respectively, in the MB-Pb2+ system, which was much lower than that in the single component system (358.4 mg g-1 100.9 mg g-1 for MB and Pb2+, respectively). Hence, simultaneous adsorption of MB and Pb2+ onto CLLS was an antagonistic adsorption. In addition, an apart-sequential adsorption method was used to study the action of adsorption sites on CLLS for MB and/or Pb2+ with the help of an efficient self-made apparatus. Rudimental results showed that there would be three different kinds of adsorption sites on CLLS: MB-site, Pb2+-site and MB/Pb2+- shared sites. Furthermore, in the MB (100 mg.L-1)-Pb2+(50.0 mg.L-1) system, the simultaneous removal efficiency of MB and Pb2+ still maintained 91.8% and 85.0%, respectively, after 6 cycles.

A free radical alkylation of quinones with olefins.

We demonstrated herein an Fe(iii)-mediated radical alkylation of quinones. A wide range of bioactive molecules with quinone motifs can be rapidly synthesized by using readily available and inexpensive NaBH4/NaBD4 with alkenes at room temperature under open flask conditions.

Silver-catalyzed stereoselective formation of glycosides using glycosyl ynenoates as donors.

A silver-catalyzed glycosylation reaction employing readily accessible and stable glycosyl ynenoates is developed. This reaction is mostly high yielding and exhibits varying levels of stereoinversion at the anomeric position. Compared to established and versatile Yu's gold catalysis, this chemistry features the use of substantially cheaper AgNTf2.

Recent Advances in the Development of Small-Molecular Inhibitors Target HIV Integrase-LEDGF/p75 Interaction.

Lens epithelium-derived growth factor (LEDGF/p75) plays an essential role in the HIV-1 replication. It acts by tethering integrase (IN) into the host cellular chromatin. Due to its significance of the IN-LEDGF/p75 interaction affords a novel therapeutic approach for the design of new classes of antiretroviral agents. To date, many small molecules have been found to be the inhibitors of INLEDGF/ p75 interaction. This review summarizes recent advances in the development of potential structure-based IN-LEDGF/p75 interaction inhibitors. The work will be helpful to shed light on the antiretroviral drug development pipeline in the next future.

Development of calixarenes, cyclodextrins and fullerenes as new platforms for anti-HIV drug design: an overview.

The research and development of calixarenes, cyclodextrins and fullerenes, which constitute the major classes of supramolecular organic host compounds, have been quite rapidly developing, increasingly active and newly rising highlight interdisciplinary fields. Numerous efforts have been directed toward such molecules as new platforms for anti- HIV drug design. This work briefly reviewed the recent development of calixarenes, cyclodextrins and fullerenes as new chemical entities of distinct anti-HIV activities. It is hoped that this review will serve as a stimulant for new thoughts in the quest for rational designs of more active and less toxic biological molecules as anti-HIV drugs.