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Cross-coupling of N-tosylhydrazones with chromium Fischer carbene complexes under catalyst-free conditions has been developed. This protocol employs stable carbene complexes and reactive diazo compounds, which are in situ generated from N-tosylhydrazones. Through hydrolysis of the initially formed methyl enolate products, the diarylethanone derivatives could be obtained in moderate to good yields.

Three new isomeric monoterpene indole alkaloids, naucleofficines I-III (1-3, resp.) were isolated from the stems (with bark) of Nauclea officinalis. Their structures were elucidated on the basis of spectroscopic methods and single-crystal diffraction analyses. The cytotoxic activities of 1-3 against human colon cancer, human gastric cancer, and human hepatoma cells were also investigated.

The photochemical behavior of methyl-substituted aromatic γ,δ-epoxy ketones was investigated by irradiation with a 500 W high-pressure mercury lamp in benzene which led to the formation of 4-methyleneisochromanols through δ-hydrogen abstraction–epoxy rearrangement–1,5-biradical cyclization reactions.

This Perspective provides a contemporary understanding of the shape evolution of colloidal metal nanocrystals under thermodynamically and kinetically controlled conditions. It has been extremely challenging to investigate this subject in the setting of one-pot synthesis because both the type and number of seeds involved would be changed whenever the experimental conditions are altered, making it essentially impossible to draw conclusions when comparing the outcomes of two syntheses conducted under different conditions. Because of the uncertainty about seeds, most of the mechanistic insights reported in literature for one-pot syntheses of metal nanocrystals with different shapes are either incomplete or ambiguous, and some of them might be misleading or even wrong. Recently, with the use of well-defined seeds for such syntheses, it became possible to separate growth from nucleation and therefore investigate the explicit role(s) played by a specific thermodynamic or kinetic parameter in directing the evolution of colloidal metal nanocrystals into a specific shape. Starting from single-crystal seeds enclosed by a mix of {100}, {111}, and {110} facets, for example, one can obtain colloidal nanocrystals with diversified shapes by adjusting various thermodynamic or kinetic parameters. The mechanistic insights learnt from these studies can also be extended to account for the products of conventional one-pot syntheses that involve self-nucleation only. The knowledge can be further applied to many other types of seeds with twin defects or stacking faults, making it an exciting time to design and synthesize colloidal metal nanocrystals with the shapes sought for a variety of fundamental studies and technologically important applications.

A novel and facile oxyazidation of alkenes under metal-free and mild conditions has been reported. A remarkable feature of the developed procedure is consecutive construction of C-O and C-N bonds in one step. The process allows quick and selective assembly of alkyl azide from readily available starting materials, where N-hydroxyphthalimide was used as an oxygen-radical precursor and TMSN3 as the N3 source. A range of aromatic alkenes bearing synthetically useful functional groups was tolerated.

2H-Chromene is an important structural motif that exists in natural products and non-natural compounds possessing interesting biological activities. In this investigation, a highly efficient approach toward 2H-chromenes has been developed based on palladium-catalyzed coupling of N-tosylhydrazones and β-bromostyrenes. The mechanism of this reaction is proposed that involves the formation of vinyl palladium by carbene migratory insertion and the intramolecular nucleophilic substitution.

Arylalkynes can be selectively converted into α-diketones under copper catalysis, and also into vinyl acetates under metal-free conditions, using PhI(O-Ac)2 as oxidant.

isolation, structure and cytotoxicity of oxyphyllumflavone A and B, the first naturally occurring flavones possessing a six-membered 6-methyl-α-pyrone ring

Three new isocoumarins, caudacoumarins A-C (I), are isolated along with two known ones from the bark of Lindera caudata.

A novel approach to 1,3-dienes having one double bond in a carbocyclic or oxacyclic ring by Pd-catalyzed coupling of α-diazoketones and lactones with vinyl boronic acids is presented.

This method has good functional group tolerance and provides a novel alternative for the efficient synthesis of highly substituted furan derivatives.

A new method for the arylative cyclization of o-alkynylphenols with aryldiazonium salts via dual photoredox/gold catalysis is described. The reaction proceeds smoothly at room temperature in the absence of base and/or additives and offers an efficient approach to benzofuran derivatives. The scope of the transformation is wide, and the limitations are discussed. The reaction is proposed to proceed through a photoredox-promoted generation of a vinylgold(III) intermediate that undergoes reductive elimination to provide the heterocyclic coupling adduct.

Oxadiazinoisoquinolinones are obtained in the presence of Na2CO3, while (isoquinolinoolinyloxy)acetamides are produced when Cs2CO3 is used as the base.

Ferrocene and its derivatives are commonly used electrochemically responsive materials. Ferrocene derivatives have attracted much attention due to their high chemical stability, characteristic electrochemical response and high liquid crystallinity. Azobenzene and its derivatives are important light responsive materials and possess outstanding photochemical properties due to the presence of an azo bond which can isomerize reversibly between trans- and cis-forms under different illumination conditions. These kinds of compounds have been designed for information storage devices, molecular switches, molecular devices and so on. By combining a ferrocene group with an azobenzene group, novel functional materials with outstanding properties of both ferrocene and azobenzene can be obtained. These novel functional materials can be used for wide range of applications like high density information storage, ion recognition, DNA detection, etc. This review summarizes recent progress in ferrocene- and azobenzene-based photoelectric responsive materials, including their synthesis, properties and applications.

A highly enantioselective Michael addition of pyrazolin-5-ones with β-CF3-β-disubstituted nitroalkenes catalyzed by bifunctional squaramide has been developed. Various chiral β-CF3-β-5-hydroxy-pyrazolin-3-yl-disubstituted nitroalkane derivatives bearing all-carbon quaternary stereocenter were prepared in good yields (up to 88%) and excellent enantioselectivities (up to 97% ee).

The tandem intramolecular cyclization-thiolation of trienes affords trifluoromethylthiolated benzolactams and -benzolactones, respectively.

Broensted acid Tf2NH catalyzes Friedel—Crafts type head-to-tail hydroalkenylation and hydroarylation of vinylarenes [(I), (III), (V), and (VII)] under mild reaction conditions providing a readily scalable, metal-free, and practical access to bioactive trans-1,3-diaryl-1-butenes [(II), (IV), and (IX)] and cyclic analogues [(VI) and (VIII)] and 1,1-diarylalkanes (XI), resp., in high regioselectivity.

A highly diastereoselective dearomatization of indoles via palladium-catalyzed decarboxylative alkynyl termination was developed. This protocol provides dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing congested stereocenters, which led to operationally simple conditions, short time, and broad substrate scope. Additionally, this reaction system could be scaled to gram quantities in a satisfactory yield and diastereoselectivity.

In this study, a concise and atom-economical TfOH-mediated [2 + 2 + 2] cycloaddition of ynamides with two discrete nitriles is developed to synthesize multi-substituted 4-aminopyrimidine. A variety of functional groups and sterically and electronically diverse reaction partners are tolerated. The products were obtained in good to excellent yields.

We present a metal-free [2 + 2 + 2] cycloaddition of ynamides with nitriles that enables highly efficient access to 2,4-diaminopyridines. This catalytic protocol is more environmentally friendly and allows for a concomitant construction of C–C and C–N bonds between ynamides and nitriles, exhibiting excellent chemoselectivity, regioselectivity, and wide functional groups tolerance.

The reactions of p-toluenesulfonylmethyl isocyanide (TosMIC) with α-bromocarbonyl compounds leading efficiently to α-sulfonated ketones, esters, and amides were reported, in which an explicit new role of TosMIC as the sulfonylating agent was uncovered for the first time. Mechanistic study by control experiments and DFT calculations suggested that the reaction is initiated by Cu(OTf)2-catalyzed hydration of TosMIC to form a formamide intermediate, which undergoes facile C–S bond cleavage under the mediation of a Cs2CO3 additive.

A CuTC-promoted C–N cross-coupling of 1,2-di(pyrimidin-2-yl) disulfides with N-heterocyclic compounds including indoles, triazole benzotriazole, and benzoimidazole by C–S cleavage of the disulfides is reported.

A series of new magnesium copper pnictide intermetallics, A2Mg3Cu9Pn7 (A = Sr, Eu; Pn = P, As) and Eu5Mg2.39Cu16.61As12, were synthesized through high temperature flux reactions. By the single-crystal X-ray diffraction technique, their structures were accurately determined. Sr2Mg3Cu9P7, Eu2Mg3Cu9P7, Sr2Mg3Cu9As7 and Eu2Mg3Cu9As7 crystallize in the Zr2Fe12P7 structure type (S.G. P, no. 174) with cell parameters: a = 9.7736(19)/9.7417(7)/10.0550(10) A/10.0410(8) A, c = 3.9280(16)/3.9008(5)/4.0544(9)/4.0364(6) A, respectively, while Eu5Mg2.39Cu16.61As12 adopts the Zr5Co19P12 structure type (S.G. P2m, no. 189) with cell parameters of a = 13.2521(6) A and c = 4.0910(3) A. These compounds can be viewed as an extensive branch of the ternary RE−M−Pn system (RE = rare-earth elements; M = transition metals; Pn = pnictogen) with the metal-to-nonmetal ratio being close or equal to 2 : 1. Interestingly, with the divalent alkaline-earth cations being introduced, these metal-rich phases exhibit electron deficiency according to the DFT calculations. Eu2Mg3Cu9As7 is metallic based on the resistivity measurement, consistent with theoretical prediction, and the magnetic susceptibility data of Eu2Mg3Cu9As7 confirmed the divalent oxidation state and weak ferromagnetic coupling for the europium cations.

Luminescence property of low-concentration Eu2+-doped SrAlSi4N7:Ce3+ yellow phosphor is reported in this paper. Three optical centers Ce1, Ce2, and Eu2 are observed in the phosphor. Deconvolution of emission spectrum confirms the three centers to be green (530 nm), yellow (580 nm), and red (630 nm), respectively. This property promises considerable improvement of color-rendering property of a white light-emitting diode (wLED). For example, color-rendering index (CRI) of wLED fabricated by combining a blue LED chip and SrAlSi4N7:0.05Ce3+,0.01Eu2+ phosphor reaches 88. A competitive energy transfer process between Ce1–Ce2 and Ce1–Eu2 is confirmed based on Inokuti–Hirayama formula. Ratio of energy transfer rate between Ce1–Ce2 and Ce1–Eu2 (WCe1–Eu2/WCe1–Ce2) is calculated to be 2.0. This result reveals the effect of Eu2+ concentration on quantity of green and red components in SrAlSi4N7:Ce3+,Eu2+ phosphor.

A metal-free alkyl radical induced addition/cyclization reaction of acrylamide has been developed. The process involved C(sp3)–H bond cleavage, alkylation of the double bond, and intramolecular cyclization, which provides a new method for the synthesis of 4-substituted isoquinoline-1,3(2H,4H)-dione derivatives. In addition, the product can be easily transformed into tetrahydrofuro[2,3-c]isoquinolin-5(2H)-one derivatives in moderate yield.

A new method for the synthesis of di- and trisubstituted pyrroles via copper-catalyzed cyclization of ethyl allenoates with activated isocyanides has been developed. In contrast to related annulation reactions previously reported, this new process features a skeletal rearrangement in which the aryl sulfonyl moiety, which functions as the electron-withdrawing group in the α-carbon of the isocyanide, was found to migrate to the γ-carbon of the starting allenoate in the final product for the first time.

Two new compounds, 11,11′-dimer of scopoletin ( 1 ) and 11- O - β -glucopyranosylhamaudol ( 2 ), together with seven known compounds were isolated and identified from the whole grass of Cicuta virosa . The chemical structures of the isolated compounds were elucidated using different spectroscopic methods. In addition, the chemical constituents were evaluated for multidrug resistance reversing activity towards doxorubicin-resistant K562/A02 cells. Compounds 1 , 8 , and 9 were endowed with remarkable MDR reversing effects.

A transition-metal-free approach was disclosed for intermolecular aryl C–N bonds formation between phenols and cyclic anilines via cross-dehydrogenative coupling (CDC) amination that was mediated by visible light, wherein K2S2O8 served as an external oxidant. The salient features of this protocol include circumventing the requirement for prefunctionalized starting materials and achieving single regioselectivity of amination adducts at room temperature.

Electrochemical capacitors (i.e. supercapacitors) include electrochemical double-layer capacitors that depend on the charge storage of ion adsorption and pseudo-capacitors that are based on charge storage involving fast surface redox reactions. The energy storage capacities of supercapacitors are several orders of magnitude higher than those of conventional dielectric capacitors, but are much lower than those of secondary batteries. They typically have high power density, long cyclic stability and high safety, and thus can be considered as an alternative or complement to rechargeable batteries in applications that require high power delivery or fast energy harvesting. This article reviews the latest progress in supercapacitors in charge storage mechanisms, electrode materials, electrolyte materials, systems, characterization methods, and applications. In particular, the newly developed charge storage mechanism for intercalative pseudocapacitive behaviour, which bridges the gap between battery behaviour and conventional pseudocapacitive behaviour, is also clarified for comparison. Finally, the prospects and challenges associated with supercapacitors in practical applications are also discussed.

A series of 1,4-disubstituted 1,2,3-triazoles containing formyl was synthesized from a variety of readily available nitrobenzaldehydes and alkynes via a convenient one-pot, click-SNAr reaction with moderate to excellent yields. The reactions were easily carried out in hexamethyl phosphoramide in the absence of a base at 60 °C.

The scalable procedure provides tryptamine derivatives in high yields and with high enantioselectivities.

The mechanism-oriented reaction design for the divergent synthesis of chiral molecules from simple starting materials is highly desirable. In this work, aromatic amide-derived nonbiarylatropisomer/silver (silver/Xing-Phos) complex was used to catalyze the Michael addition of glycine aldimino esters to chalcones and successfully applied to the subsequent cyclocondensation to afford substituted cis-Δ(1)-pyrroline derivatives with up to 98 % ee. Besides the inherent performance of the chiral Ag/Xing-Phos catalyst system, it was found that the workup of such reactions played an important role for the stereoselective construction of stereodivergent Δ(1)-pyrrolines, in which an epimerization of the cis-Δ(1)-pyrrolines to the trans-isomers during was revealed.

By combining Pb2+ with ds-block elements, a new double phosphate PbCd(PO3)4 has been synthesized for the first time. It crystallizes in space group P21/n of the monoclinic system with unit cell parameters of a = 7.1191 (14) A, b = 9.0871 (18) A, c = 14.681 (3) A, β = 91.40 (3)° and Z = 4. Its structure contains [ PO 3 ] 1 ∞ chains running along the a direction, which are further bridged by isolated [CdO6] triangular prisms to generate a 3D framework with Pb2+ cations filling in the cavities. Based on UV-vis-NIR spectroscopy measurement, PbCd(PO3)4 has a large band gap of 4.85 (2) eV, which is consistent with the density functional theory (DFT) study. In addition, the DSC curve demonstrates that PbCd(PO3)4 melts congruently at 727 °C. Additionally, the title compound displays a UV-photocatalytic activity to decompose RhB under 500 W mercury lamp (λ = 256 nm) radiation about 0.62 times that of P25 (TiO2).

The title compound (I), called perovskiaol, exhibits significant cytotoxic activity inhibiting NB4, A549 as well as HepG2 cells.

A photo-induced catalyst-free three-component reaction of N-(2-iodoaryl)acrylamide, sulfur dioxide, and hydrazine is reported. Under ultraviolet irradiation, diverse (2-oxoindolin-3-yl)methanesulfonohydrazides are generated in moderate to good yields. During the process, the sulfonyl group can be easily incorporated via insertion of sulfur dioxide in the absence of any metals or photo-redox catalysts under mild conditions. A plausible mechanism is proposed, which involves 5-exo radical cyclization and subsequent insertion of sulfur dioxide.

Recent advances in photoinduced trifluoromethylation and difluoroalkylation under photocatalysis are summarized. Most of the photoredox reactions proceed efficiently under mild conditions with simple operation. Various fluorinated reagents are developed and applied in different transformations. Usually, the photocatalyst in a photocatalytic cycle is initially stimulated to the excited state in the presence of visible light, which then provides an electron to the fluorinated reagent to release a CF3 radical or CF2 radical. The subsequent radical addition to an unsaturated bond with further transformations would produce the corresponding fluorinated products. Alkenes, alkynes, isocyanides, and arenes are frequently employed as substrates for access to fluorochemicals. The advantages of trifluoromethylation and difluoroalkylation under photocatalysis including mild reaction conditions, good functional group tolerance, and experimental ease will make the approaches attractive for further applications.

A mild approach for direct C2 sulfonylation of heteroaromatic N-oxides with sulfonyl hydrazides affording 2-sulfonyl quinolines/pyridines has been developed. A variety of heteroaromatic N-oxides and sulfonyl hydrazides participate effectively in this transformation which uses hypoiodites (generated in situ from NaI and TBHP) as a means of substrate activators. In this reaction, the N-oxide plays a dual role, acting as a traceless directing group as well as a source of oxygen atom.

Three novel furan-2-carboxylic acid derivatives are isolated from the leaves of Nicotiana tabacum together with two known compounds.

The highly diastereoselective and enantioselective title reaction of aryl substituted cyclopropyl ketones with mercaptoacetaldehyde is described.

The study of gas phase ion-molecule reactions by state-of-the-art mass spectrometric experiments in conjunction with quantum chemistry calculations offers an opportunity to clarify the elementary steps and mechanistic details of bond activation and conversion processes. In the past few decades, a considerable number of publications have been devoted to the ion-molecule reactions of metal clusters, the experimentally and theoretically tractable models for the active phase of condensed phase systems. The focus of this perspective concerns progress on activation and transformation of important inorganic and organic molecules by negatively charged metal clusters. The metal cluster anions cover bare metal clusters as well as ligated systems with oxygen, carbon, and nitrogen, among others. The following important issues have been summarized and discussed: (i) dependence of chemical reactivity and selectivity on cluster structures and sizes, metals and metal oxidation states, odd-even electron numbers, etc. and (ii) effects of doping, ligation, and pre-adsorption on the reactivity of metal clusters toward rather inert molecules.

An unprecedented diarylheptanoid derivative with 6/5/5 fused rings, diocollettines A (1), together with five known compounds (2-6) were isolated from the rhizomes of Dioscorea collettii. The structures were elucidated by extensive NMR spectroscopic analysis, together with HR-ESI-MS techniques. The absolute configuration of compound 1 was unambiguously confirmed by comparison of experimental data with calculated electronic circular dichroism (ECD) spectra and single-crystal X-ray diffraction analysis. Compound 1 exhibited moderate cytotoxicity against NCL-H460. (C) 2016 Elsevier Ltd. All rights reserved.

Two new ternary copper-containing arsenides, Sr2Cu3As3 and Eu2Cu3As3, were synthesized through Pb-flux reactions. In combination with theoretical calculations, the crystal structures of these compounds were determined through single-crystal X-ray diffraction. Both compounds crystallize in the orthorhombic space group Cmcm (no.63) with the cell parameters a = 4.2465(6)/4.1866(5) A, b = 17.604(3)/17.486(2) A, and c = 4.2552(6)/4.2096(5) A for the Sr- and Eu-containing compounds, respectively. Temperature-dependent magnetic susceptibility measurements suggest that both ferromagnetic and antiferromagnetic coupling exists in the structure of Eu2Cu3As3 for the Eu 4f states. According to DFT calculations, these compounds are metallic, and the Cu 3d orbitals make significant contributions to the states around the Fermi level.

Here we report that an excess amount of aldehyde, in particular, aliphatic aldehyde, without any additives, efficiently facilitates the oxidation of aminal intermediates to quinazolinones in pure water.

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

A metal-free and cost-effective protocol for UV light-mediated difunctionalization of alkenes with CF3SO2Na was developed. This strategy realized the direct formation of Csp3–CF3 and C–C bonds through a proposed tandem radical cyclization process, which produced a variety of phenanthrene and anthrone derivatives in moderate yields.

Asymmetric hydrogenation of various α-substituted acrylic acids was carried out using RuPHOX–Ru as a chiral catalyst under 5 bar H2, affording the corresponding chiral α-substituted propanic acids in up to 99% yield and 99.9% ee. The reaction could be performed on a gram-scale with a relatively low catalyst loading (up to 5000 S/C), and the resulting product (97%, 99.3% ee) can be used as a key intermediate to construct bioactive chiral molecules. The asymmetric protocol was successfully applied to an asymmetric synthesis of dihydroartemisinic acid, a key intermediate required for the industrial synthesis of the antimalarial drug artemisinin.