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Natural products have historically been, and continue to be, an invaluable source for the discovery of various therapeutic agents. Oridonin, a natural diterpenoid widely applied in traditional Chinese medicines, exhibits a broad range of biological effects including anticancer and anti-inflammatory activities. To further improve its potency, aqueous solubility and bioavailability, the oridonin template serves as an exciting platform for drug discovery to yield better candidates with unique targets and enhanced drug properties. A number of oridonin derivatives (e.g. HAO472) have been designed and synthesized, and have contributed to substantial progress in the identification of new agents and relevant molecular mechanistic studies toward the treatment of human cancers and other diseases. This review summarizes the recent advances in medicinal chemistry on the explorations of novel oridonin analogues as potential anticancer therapeutics, and provides a detailed discussion of future directions for the development and progression of this class of molecules into the clinic.

Six new dicyclic polyprenylated acylphloroglucinol derivatives, hyperhenones A-F (1-6), together with twelve known analogues, were isolated from the aerial parts of Hypericum heniyi. Their structures were elucidated based on the comprehensive MS and NMR spectroscopic data. The inhibitory activities of these isolates on four human tumor cell lines were assayed, and compounds 5, 7, and 10 showed significant inhibitory effects with the IC50 1.3-8.8 mu M. (C) 2015 Elsevier Ltd. All rights reserved.

Hypercohin K (1), the first polycyclic polyprenylated acylphloroglucinol possessing a unique spiro-fused cyclopropane ring, together with hyphenrone L (2) representing the most complex congeners featured with a hexacyclic core, was isolated from Hypericum cohaerens. The structure of 1 was elucidated by extensive MS and NMR spectroscopic data. The absolute configuration was defined by comparison of the experimental and calculated ECD. Compound 1 was evaluated for the inhibitory activities against acetylcholinesterase and four human tumor cell lines. (C) 2015 Elsevier Ltd. All rights reserved.

Photochromic diarylethenes were deemed to be one of the most promising molecular building blocks for photoresponsive materials. This review gives a brief summary to the recent progress of studies of diatylethenes in supramolecular systems, focusing on their applications in biological systems, photoresponsive mechanical materials and photoresponsive chemosensors. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Starting from 2-benzylidenebenzofuran-3-ones the synthesis of chiral dihydropyran-fused benzofurans is elaborated.

Stilbenes react with the hypervalent iodine compound (II) as nitrogen source to give intermediate imines which undergo iron catalyzed conversion into various benzamides in the presence of air.

A Cu(I)-catalyzed direct intermolecular oxyamination of electron deficient alkenes is disclosed. This process is characterized by difunctionalization of a variety of α,β-unsaturated ketones with easily available N-acyloxyamine reagents as both amine and oxygen donors, which delivers ester derivatives of β-amino alcohols in good yields as well as with high regioselectivity. Control studies suggested the involvement of alkyl radical species on the way of product formation.

Reported is the first oxy-trifluoromethylation of allylamines with carbon dioxide (CO2 ) using copper catalysis, thus leading to important CF3 -containing 2-oxazolidones. It is also the first time CO2 , a nontoxic and easily available greenhouse gas, has been used to tune the difunctionalization of alkenes from amino- to oxy-trifluoromethylation. Of particular note, this multicomponent reaction is highly chemo-, regio-, and diastereoselective under redox-neutral and mild reaction conditions. Moreover, these reactions feature good functional-group tolerance, broad substrate scope, easy scalability and facile product diversification. The important products could also be formed with either spirocycles or two adjacent tetrasubstituted carbon centers.

The title compound (II), a key intermediate for the synthesis of the anti-psychotic drug olanzapine, is prepared by intramolecular cyclocondensation of [(nitrophenyl)amino]thiophenecarbonitrile (I) using tin powder and HCl a reducing system.

A AgF/TFA-promoted highly efficient synthesis of a wide range of α-haloketones from haloalkynes is described. The reactions are conducted under convenient conditions and provide products in moderate to excellent yields, with broad substrate scope, including a variety of aromatic chloroalkynes and bromoalkynes.

One-dimensional nonlinear optical edge states of a single atomic membrane of MoS2 epitaxially grown by chemical vapor deposition are observed by second harmonic generation measurements.

A chiral iridium(I) N-heterocyclic carbene complex was reported for the first time as the catalyst in the highly enantioselective intramolecular allylic amination reaction. The current method provides facile access to biologically important enantioenriched indolopiperazinones and piperazinones in good yields (74-91 %) and excellent enantioselectivities (92-99 % ee). Preliminary mechanistic investigations reveal that the C-H activation occurs at the position ortho to the N-aryl group of the ligand.

Mechanochromic organic materials are a typical class of stimuli materials that has response to external physical stimuli such as shearing, grinding, and compressing etc. Organic compounds with mechanochromic characters in solid forms have attracted significant attention in the past decades due to their potential applications in sensors and memory devices. Diamond anvil cell is an emerging technology that can provide isotropic pressure in a tiny place. Thus a new stimuli method can be applied in investigating optical variation of mechanochromic materials. In this review, we focus on mechanoluminescence systems that are responsive to isotropic compression under high pressure and summarize the recent advances on organic materials studied by the diamond anvil cell.

An expeditious synthesis of norwogonin, isoscutellarein, and herbacetin, has been accomplished by a strategy featuring a borylation of sterically hindered aryl iodide and a one-pot oxidation to generate the C-3 and C-8 OH groups. The total synthesis gives excellent yields and conventional flash column chromatography is not needed for purification.

A zinc-catalyzed oxidative reaction of ynamides with phenols and thiophenols under mild reaction conditions has been developed, which provides various α-aryloxy amides and α-arylthio amides in moderate to good yields, respectively. Importantly, high chemoselectivity is achieved by such a non-noble metal-catalyzed alkyne oxidation.

The coupling of multi-step reactions catalyzed by a heterogeneous catalyst is an important path to accomplish some unconventional chemical transformations. Since the starting materials generated from previous steps were adsorbed on the catalyst, the activation energy of following steps was largely decreased, and thus the reaction conditions were more mild and environmental friendly. Catalyzed by a multifunctional Cu–Pd/γ-Al2O3 catalyst, the transfer hydrogenation and successive cyclization coupling reaction from o-nitroaniline and alcohol to afford benzimidazole derivatives in high yield was realized. The catalyst could be reused several times without loss of activity. The synergies of reforming hydrogenation of Cu–Pd bimetal and support acidity of γ-Al2O3 were responsible for this catalytic transformation.

A metal-free TBHP-mediated radical alkylation of enol acetates with alcohols is described. This method provides a new route to a variety of β-hydroxy-ketones in moderate to good yields.

A stereoselective Koenigs-Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).

The enantioselective N-heterocyclic carbene-catalyzed [2 + 4] cyclocondensation of α-chloroaldehydes and saccharine-derived 1-azadienes was developed, giving the corresponding saccharine-derived dihydropyridinones in good yields with exclusive cis-selectivities and excellent enantioselectivities.

A novel gold-catalyzed intermolecular ynamide amination-initiated aza-Nazarov cyclization has been developed, allowing the facile and efficient synthesis of various 2-aminopyrroles in moderate to good yields. Furthermore, a mechanistic rationale for this tandem sequence, especially for the observed high regioselectivity, is also well supported by DFT (density functional theory) computations. The high flexibility, broad substrate scope, and mild nature of this reaction render it a viable alternative for the construction of 2-aminopyrroles.

Multiple-bonded iron-oxo and -nitrido species have been identified or proposed as key intermediates in a range of important chemical transformations. The reported model complexes feature various coordination geometries and distinct electronic structures, and therefore exhibit diverse reactivity. The present contribution highlights the synergy from both experimental and theoretical standpoints to elucidate their different bonding situations and delineate their common mechanistic features in hydrogen-atom abstraction processes. Our analysis reveals that a radical centered on the abstracting atom E (E=O, N), which is generated via homolysis of covalent Fe−E bonds upon approaching the transition state, is an intrinsic C−H cleaving agent. The iron-oxo species is predicted to be more reactive than its nitride congener, in general, because the O−H bond formed in the H-atom transfer process is often stronger than the corresponding N−H bond.

N-Containing tricyclic compounds, especially the tricyclic N-heterocycles, are important structural motifs that possess significant potential in organic chemistry for their momentous applications in natural and man-made bioactive molecules. Gold catalysis, which exhibits specific catalytic properties in terms of both high reactivity and selectivity for various organic transformations, has proven to be a powerful tool for the straightforward synthesis of cyclic compounds, especially the polycyclic molecules. Currently, several approaches towards polycycle synthesis have been developed via gold-catalyzed transformations of readily available ynamides. In this review, we will focus on the recent advances in the gold-catalyzed construction of N-containing tricycles based on ynamides by highlighting their specificity and applicability, and the mechanistic rationale is presented where possible.

A practical and efficient method for the preparation of 1,5-benzothiazepinone derivatives in good yields has been developed using tetrabutylammonium fluoride (TBAF) as a catalyst. This study not only expands the previous work on the substrate scope and also provides more understanding of the chemistry of such drug scaffolds.

Methods for trifluoromethylthiolation are very limited. To tackle this problem, a mild and efficient approach to the 2-trifluoromethylthiolation of glycals has been developed. This protocol employed N-trifluoromethylthiosaccharin as the trifluoromethylthiolating reagent, TMSCl as the activator, and DBU as the base, affording 2-trifluoromethylthioglycals in good yields. These trifluoromethylthiolated carbohydrates may benefit the development of carbohydrate-based drugs.

A novel and atom economical copper-catalyzed diesterification of 1,3-dienes has been developed; the available allylic diester derivatives, which are the important intermediates for the synthesis of natural products, were attained with moderate to good yields. Preliminary mechanistic study suggests that allylic radical might be involved in this transformation.

A novel and convergent approach to tetrasubstituted benzofurans was developed from ortho-bromo aryl fluorides and keto-amides via one-pot SNAr displacement and subsequent Cu(I) catalyzed C–O coupling on the ortho-bromide. The scope of this methodology was demonstrated on several similar substrates.

Nanometal materials play very important roles in solar-to-chemical energy conversion due to their unique catalytic and optical characteristics. They have found wide applications from semiconductor photocatalysis to rapidly growing surface plasmon-mediated heterogeneous catalysis. The recent research achievements of nanometals are reviewed here, with regard to applications in semiconductor photocatalysis, plasmonic photocatalysis, and plasmonic photo-thermocatalysis. As the first important topic discussed here, the latest progress in the design of nanometal cocatalysts and their applications in semiconductor photocatalysis are introduced. Then, plasmonic photocatalysis and plasmonic photo-thermocatalysis are discussed. A better understanding of electron-driven and temperature-driven catalytic behaviors over plasmonic nanometals is helpful to bridge the present gap between the communities of photocatalysis and conventional catalysis controlled by temperature. The objective here is to provide instructive information on how to take the advantages of the unique functions of nanometals in different types of catalytic processes to improve the efficiency of solar-energy utilization for more practical artificial photosynthesis.

An efficient Pd(OAc) 2 /Cu(Xantphos)I system for Sonogashira coupling is disclosed. Aryl bromides/iodides and electron-poor aryl chlorides were suitable for this reaction. The experimental results suggest that Cu(Xantphos)I plays a unique role in which the phosphine ligand coordinates with copper.

The crystal structure, magnetic properties and magnetocaloric effect (MCE) of GdCoC2 have been studied. The compound crystallizes in an orthorhombic CeNiC2-type structure which belongs to the Amm2 space group. A giant reversible MCE is observed in GdCoC2 accompanied by a second-order paramagnetic to ferromagnetic (PM–FM) phase transition around the Curie temperature ∼15 K. For the magnetic field change of 0–5 T, the maximum values of the magnetic entropy change (−ΔSmaxM), relative cooling power (RCP), and refrigerant capacity (RC) are 28.4 J kg−1 K−1, 566 J kg−1 and 369 J kg−1, respectively. The present results indicate that GdCoC2 is a promising candidate for low temperature magnetic refrigeration.

The 3-butenyloxycarbonyl group can be introduced into carbohydrates such as (I) under mild conditions.

The title compounds are prepared by a reactive flux method involving K2Q2 (Q: S, Se) as the flux, Ga2Se3, Ge or Si, and Q in the molar ratio of 2.25:0.375:0.5:1.75 (evacuated silica tubes, 750 °C, 3 d; ≈80% yield).

Luminescence of porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) is sensitive to the type and concentration of chemical species in the surrounding environment, because these materials combine the advantages of the highly regular porous structures and various luminescence mechanisms, as well as diversified host-guest interactions. In the past few years, luminescent MOFs have attracted more and more attention for chemical sensing of gas-phase analytes, including common gases and vapors of solids/liquids. While liquid-phase and gas-phase luminescence sensing by MOFs share similar mechanisms such as host-guest electron and/or energy transfer, exiplex formation, and guest-perturbing of excited-state energy level and radiation pathways, via various types of host-guest interactions, gas-phase sensing has its unique advantages and challenges, such as easy utilization of encapsulated guest luminophores and difficulty for accurate measurement of the intensity change. This review summarizes recent progresses by using luminescent MOFs as reusable sensing materials for detection of gases and vapors of solids/liquids especially for O2, highlighting various strategies for improving the sensitivity, selectivity, stability, and accuracy, reducing the materials cost, and developing related devices.

A new type of sulfoxide, 4-(2-(2-(methylsulfinyl) ethyl)-4-nitrophenyl)- morpholine (I), was designed and prepared in good yield. Upon the combination of I and bis(trichloromethyl)carbonate, the Swern oxidation of primary and secondary alcohols was significantly promoted under mild conditions, which afforded the corresponding aldehydes or ketones in good yields. It is noteworthy that the reoxidation of the isolated by-product sulfide V could be further recycled in Swern oxidation.

Two novel monoterpenoid indole alkaloids (MIAs) with a third nitrogen atom, winchinines A (1) and B (2), along with three known ones (3–5) were isolated from the twigs and leaves of Winchia calophylla. Compound 1 is the first natural MIA possessing a 6/5/6/5/6/5 hexacyclic ring system with an oxazolidinone unit. Compound 2 is an unprecedented cyano-substituted aspidosperma-type alkaloid. Their structures with absolute configurations were elucidated by means of NMR spectroscopy, single crystal X-ray diffraction, and electronic circular dichroism data analyses.

We report the asymmetric vinylogous Mannich reactions (VMRs) of N-Boc-2-tert-(butyldimethylsilyloxy)pyrrole (TBSOP) with N-tert-butanesulfinylimines. The reaction is highly anti-diastereoselective and shows good generality for the direct construction of a variety of vicinal anti-diamine motifs that are found in a number of biologically active alkaloids and medicinal agents. A VMR adduct was elaborated in six steps into the 1-aminopyrrolizidine alkaloid (+)-absouline, which constitutes the second and also the most efficient total synthesis of the natural enantiomer of the title alkaloid.

The bifunctional N-heterocyclic carbene catalyzed [3 + 4] annulation of enals and 5-alkenyl thiazolones was developed, giving the corresponding thiazole-fused e-lactones in high yields with excellent diastereoselectivties and enantioselectivities. The thiazole-fused e-lactone could be isomerized to the spirocyclic thiazolone–cyclopentanone without erosion of enantioselectivity.

A Pd-catalyzed/N-heterocycle-directed C(sp(3) )-H olefination has been developed. The monoprotected amino acid ligand (MPAA) is found to significantly promote Pd-catalyzed C(sp(3) )-H olefination for the first time. Cu(OAc)2 instead of Ag(+) salts are used as the terminal oxidant. This reaction provides a useful method for the synthesis of alkylated pyrazoles.

A reductive coupling of aldehydes with alkenes provides secondary alcohols through a direct hydride transfer pathway.

A practical ortho C–H olefination of phenyl acetic acid derivatives was achieved with a 1,2,3-triazole auxiliary directing group. Good to excellent yields were achieved with O2 as terminal oxidant. Other bidentate directing groups, such as 8-aminoquinoline, gave poor reactivity under this aerobic condition, highlighting the unique reactivity of triazole in promoting C–H activation.

A novel strategy to synthesize 1,3-enynes has been successfully developed based on Cu(I)-catalyzed cross-coupling of α-diazo phosphonates and alkynes with a subsequent Horner–Wadsworth–Emmons (HWE) type reaction. This method provides straightforward access to conjugated enynes with high efficiency, good stereoselectivity and excellent functional group compatibility. Copper(I) carbene migratory insertion plays a crucial role in this transformation.

Elastomer posts (PDMS, 0.5—1.75 mm diameter) are dip-coated with liquid Ga (34 °C, 8.3 kPa preload pressure to break the oxide layer) followed by solidifying the Ga layer and formation of a new oxide layer on the Ga droplet in air.

We cover the achievements and thought process that have emerged as a result of the recent use of iron salts as catalysts for the oxidative coupling, addition, and functionalization on constructing C−C bonds, C−N bonds, C−O bonds, C−S bonds, and C−P bonds. These transformations concomitantly require a stoichiometric oxidant to activate the catalyst: The low-cost and ubiquity of peroxides is often used as a result of their high oxidative reactivity, resulting in the widespread utilizations of iron catalysis through the initiation of radical processes. Here, we summarize the formation of diverse chemical bonds by using iron oxidative catalysis strategies, including 1) the oxidative coupling strategy and 2) the oxidative addition and functionalization strategy. The oxidative coupling strategy focuses on the formation of one chemical bond in a single reaction, whereas the oxidative addition and functionalization strategy includes the transformations that construct at least two chemical bonds.