Controllable Phosphine-Catalyzed Three-Component Domino Reaction of Activated Alkenes with Morita-Baylis-Hillman (MBH) Carbonates: Divergent Synthesis of Densely Functionalized Cyclopentanes and Diquinanes.

An unexpected phosphine-catalyzed controllable three-component domino reaction involving [1 + 2 + 2] annulation and [1 + 2 + 2]/[3 + 2] sequential annulation reaction of 2-arylmethylidene cyanoacetates/malononitriles with Morita-Baylis-Hillman (MBH) carbonates has been developed. A broad range of densely functionalized cyclopentanes and diquinanes bearing five or four consecutive stereogenic centers, including two all-carbon quaternary stereocenters, were smoothly acquired in moderate to excellent yields under mild reaction conditions from readily available materials. Moreover, this divergent transformation enables the simultaneous generation of three or four new C-C bonds and one or two carbocyclic rings in only one step.

Base-Controlled Chemodivergent [4 + 1] and [2 + 1]/[4 + 2] Annulations of -Aminochalcones with Bromocrotonates.

Controlling the selectivity of reactions is a significantly attractive strategy in synthetic organic chemistry. Herein, an efficient base-controlled chemodivergent domino reaction between -aminochalcones and bromocrotonates has been developed. A series of -2,3-disubstituted indolines and cyclopropane-fused tetrahydroquinolines were obtained via two pathways with a broad substrate scope in moderate to excellent yields under transition-metal-free conditions.

C-Doped LiVO Honeycombs Derived from the Biomass Template Strategy for Superior Lithium Storage.

LiVO as a prospective anode for lithium-ion batteries has drawn considerable focus based on its superior ion transfer capability and relatively elevated specific capacity. Nevertheless, the inherent low electrical conductivity and sluggish reaction kinetics hindered its commercial application. Herein, C-doped LiVO honeycombs (C-doped LiVO HCs) are designed via introducing low-cost and scalable biomass carbon as a template, and the influence of the structure on the lithium storage property is systematically studied.

Highly Regio- and Diastereoselective Phosphine-Catalyzed [2 + 4] Annulation of Benzofuran-Derived Azadienes with Allyl Carbonates: Access to Spiro[benzofuran-cyclohexanes].

A novel highly regio- and diastereoselective phosphine-catalyzed [2 + 4] annulation of benzofuran-derived azadienes (BDAs) with acidic hydrogen-tethered allyl carbonates has been developed ingeniously. A range of functionalized spiro[benzofuran-cyclohexane] derivatives with two consecutive stereocenters were smoothly obtained in moderate to excellent yields under mild reaction conditions from readily available materials. Moreover, this method is a practical and scalable strategy that creates the core structural motif of the fungistatic drug, griseofulvin.

Stereoselective Synthesis of -Glycosides with Borate Acceptors.

Borate esters have been applied widely as coupling partners in organic synthesis. However, the direct utilization of borate acceptors in -glycosylation with glycal donors remains underexplored. Herein, we describe a novel -glycosylation resulting in the formation of 2,3-unsaturated -glycosides and 2-deoxy -glycosides mediated by palladium and copper catalysis, respectively.

Synthesis and inhibitory activity of euparin derivatives as potential dual inhibitors against α-glucosidase and protein tyrosine phosphatase 1B (PTP1B).

Diabetes mellitus is a serious threat to human life and health. The α-glucosidase and protein tyrosine phosphatase 1B (PTP1B) were important targets for the treatment of type 2 diabetes mellitus. In this paper, euparin, a natural product from Eupatorium chinense possessed extensive pharmacological activities, was selected as the lead compound.

Stereoselective Synthesis of 2-Deoxy Glycosides via Iron Catalysis.

An Fe-catalyzed 2-deoxy glycosylation method was developed from 3,4--carbonate glycals directly at room temperature. This novel approach enabled facile access to alkyl and aryl 2-deoxy glycosides in high yields with exclusive α-stereoselectivity, tolerating various alcohols, phenols, and glycals. The synthetic utility and advantage of this strategy have been demonstrated by the modification of six natural products and the construction of a tetrasaccharide.

Stereoselective O-Glycosylation of Glycals with Arylboronic Acids Using Air as the Oxygen Source.

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 -glycosides in high yields, with exclusive 1,4--stereoselectivity tolerating reactive hydroxyl/amino groups. Mechanistic studies indicated that chemo-/stereoselectivity arose from the coordination between palladium and phenols generated by oxidizing arylboronic acids, followed by an intramolecular attack.

Coordination effect enabled palladium-catalyzed regioselective -alkylation of 2-pyridones.

A novel tactic for the regioselective -alkylation of 2-pyridones has been realized through palladium catalysis in moderate to high yields. The coordination effect between palladium and nitrogen on the pyridine ring plays a versatile role.

Direct N-Glycosylation of Amides/Amines with Glycal Donors.

Direct N-glycosylation between glycals and amides/amines was achieved with exclusive stereoselectivity in moderate to high yields. Various amides, amines, and 3,4--carbonate-glycals were tolerated, and unique β--glycosides were obtained. The strategy was based on palladium-catalyzed decarboxylative allylation, and the high 1,4-cis-selectivity was proposed because of the hydrogen bonding effect.

Open-Air Stereoselective Construction of -Aryl Glycosides.

A new methodology of stereoselective -glycosylation has been developed with 3,4--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.

Trametenolic acid B protects against cerebral ischemia and reperfusion injury through modulation of microRNA-10a and PI3K/Akt/mTOR signaling pathways.

Trametenolic acid B (TAB) was a lanostane-type triterpenoid isolated from the trametes lactinea (Berk.) Pat. We have previously reported that extract from trametes lactinea (Berk.

Odorless Isocyanide Chemistry: One-Pot Synthesis of Heterocycles via the Passerini and Postmodification Tandem Reaction Based on the in Situ Capture of Isocyanides.

This paper reports the tandem reaction strategy of the Passerini/Staudinger/aza-Wittig reaction based on the in situ capture of isocyanides. According to this strategy, isocyanides are synthesized in situ and immediately work as the substrate for the Passerini reaction and postmodification tandem reaction in one pot. In addition, two types of new compounds, 5-oxo-3,5-dihydrobenzo[ e][1,4]oxazepines and 6-oxo-5,6-dihydro-2 H-1,4-oxazines, were synthesized using the tandem reaction strategy that includes five-step transformations in one pot.

Diastereoselective Synthesis of C-Vinyl Glycosides via Gold(I)-Catalyzed Tandem 1,3-Acyloxy Migration/Ferrier Rearrangement.

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.

Design, synthesis and biological evaluation of bisabolangelone oxime derivatives as potassium-competitive acid blockers (P-CABs).

With the aim of searching novel P-CABs, seven bisabolangelone oxime derivatives were designed, synthesized, characterized and evaluated the H(+),K(+)-ATPase inhibitory activities guided by computer aided drug design methods. The binding free energy calculations were in good agreement with the experiment results with the correlation coefficient R of -0.9104 between ΔGbind and pIC50 of ligands.

Cytotoxic 1,3-Thiazole and 1,2,4-Thiadiazole Alkaloids from Penicillium oxalicum: Structural Elucidation and Total Synthesis.

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.

Computational insights into the interaction mechanism of triazolyl substituted tetrahydrobenzofuran derivatives with H(+),K(+)-ATPase at different pH.

The interaction mechanism of triazolyl substituted tetrahydrobenzofuran derivatives (compound 1 (N, N-Dipropyl-1-(2-phenyl-4,5,6,7-tetrahydrobenzofuran-4-yl)-1H-1,2,3-triazole-4-methanamine) and 2 (1-(2-Phenyl-4,5,6,7-tetrahydrobenzofuran-4-yl)-4-(morpholin-4-ylmethyl)-1H-1,2,3-triazole)) with H(+),K(+)-ATPase at different pH were studied by induced-fit docking, QM/MM optimization and MM/GBSA binding free energy calculations of two forms (neutral and protonated form) of compounds. The inhibition activity of compound 1 is measured and almost unchanged at different pH, while the activity of compound 2 increases significantly with pH value decreased. This phenomenon could be explained by their protonated form percentages and the calculated binding free energies of protonated and neutral mixture of compounds at different pH.

Synthesis and cytotoxic activities of 2-substituted (25R)-spirostan-1,4,6-triene-3-ones via ring-opening/elimination and 'click' strategy.

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.

Effect of Culture Conditions on Metabolite Production of Xylaria sp.

Seeking a strategy for triggering the cryptic natural product biosynthesis to yield novel compounds in the plant-associated fungus Xylaria sp., the effect of culture conditions on metabolite production was investigated. A shift in the production of five known cytochalasin-type analogues 1-5 to six new α-pyrone derivatives, xylapyrones A-F (compounds 6-11), from a solid to a liquid medium was observed.

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

In this publication, we design and report the synthesis of calix[4]arene-based β-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 β-diketo derivatives inhibit strand transfer (ST) with IC50 values between 5.