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Crystals of the first sodalite-type zeolite containing an all-iron framework, a ferrolite, Ba8(Fe12O24)Nay(OH)6⋅x H2O, were synthesized using the hydroflux method in nearly quantitative yield. Ba8(Fe12O24)Nay(OH)6⋅x H2O crystallizes in the cubic space group Pm3‾m with a=10.0476(1) A. Slightly distorted FeO4 tetrahedra are linked to form Fe4O4 and Fe6O6 rings, which in turn yield channels and internal cavities that are characteristic of the sodalite structure. Barium, sodium, and hydroxide ions and water molecules are found in the channels and provide charge balance. Magnetic measurements indicate that the ferrolite exhibits magnetic order up to at least 700 K, with the field-cooled and zero-field-cooled curves diverging. Analysis of the 57Fe Mossbauer spectra revealed two spectral components that have equal spectral areas, indicating the presence of two subsets of iron centers in the structure. Dehydrated versions of the ferrolite were also prepared by heating the sample.

New complex manganese vanadate materials were synthesized as high-quality single crystals in multi-millimeter lengths using a high-temperature, high-pressure hydrothermal method. One compound, Mn5(VO4)2(OH)4, was grown from Mn2O3 and V2O5 in 3 M CsOH at 580 °C and 1.5 kbar. Changing the mineralizer to 1 M CsOH/3MCsCl leads to the formation of another product, Mn6O(VO4)2(OH). Both compounds were structurally characterized by single-crystal X-ray diffraction (Mn5(VO4)2(OH)4: C2/m, Z = 2, a = 9.6568(9) A, b = 9.5627(9) A, c = 5.4139(6) A, β = 98.529(8)°; Mn6O(VO4)2(OH): P21/m, Z = 2, a = 8.9363(12) A, b = 6.4678(8) A, c = 10.4478(13) A, β = 99.798(3)°), revealing interesting low-dimensional transition-metal features. Mn5(VO4)2(OH)4 possesses complex honeycomb-type Mn–O layers, built from edge-sharing [MnO6] octahedra in the bc plane, with bridging vanadate groups connecting these layers along the a-axis. Mn6O(VO4)2(OH) presents a more complicated structure with both octahedral [MnO6] and trigonal bipyramidal...

A method for the synthesis of 5,5-difluorosubstituted six-membered nitronates by the coupling of 2-bromo-1,1-difluoroethyl ketones with nitro alkanes is described. The reaction is mediated by 1,8-diazabicycloundec-7-ene and proceeds as a sequence of nitronate anion addition at the carbonyl group and intramolecular nucleophilic substitution of bromine.

Metal-organic frameworks (MOFs) are excellent platforms for engineering luminescence properties as their building blocks, metal ions, linkers, and guest ions or molecules, are all potential sources of light emission. Temperature is one of the most important physical properties affecting the dynamics and viability of natural and engineered systems. Because the luminescence of certain lanthanide-bearing MOFs changes considerably with temperature, in the last few years, these materials have been explored as optical thermometers, especially in temperature sensing based on the intensity ratios of two separate electronic transitions. This review discusses the main concepts and ideas assisting the design of such ratiometric thermometers, and identifies the main challenges presented to this nascent field: develop nanothermometers for bio-applications and nanomedicine; understand the energy transfer mechanisms determining the thermal sensitivity; achieve effective primary thermometers; realize multifunctional nanothermometers; integrate Ln3+ -based thermometers in commercial products.

The bioassay-directed fractionation of the roots of Radermachera boniana Dop. (Bignoniaceae) led to the isolation of 17 naphthalene-based quinones and related derivatives including the new radermacherones A (1), B (2) and C (6), radermaquinone (3), and radermacherol (5). The absolute configuration of 2 was determined through X-ray crystallographic analysis. The isolates 3, hydroxy-β-isonaphthoquinone (4), 6, α-naphthoquinone (8), β-naphthoquinone (9), 3-hydroxy-β-naphthoquinone (10), 4-oxo-β-naphthoquinone (11), 2-acetyl-naphtha[2,3-b]furan-4,9-dione (BBI608) (12), 2-acetyl-7-methoxy-naphtho[2,3-b]furan-4,9-dione(13), stenocarpoquin-one B (14), dehydro-α-isonaphthoquinone (15) and 3-hydroxydehydro-α-isonaphthoquinone (16) showed cytotoxic activity in a cancer cell line panel comprising KB, Col-2, Lu-1 and MCF-7 with IC50 values ranging from 0.15-38.6 µM. Compounds 12 (known as BBI608) and its methoxy derivative, 13 with extended conjugation showed the highest cytotoxicity among the tested compounds with IC50 values ranging from 0.12-3.33 µM, but 13 showed much different cancer cell killing selectivity than 12.

Alkyl carboxylic acids are ubiquitous in all facets of chemical science, from natural products to polymers, and represent an ideal starting material with which to forge new connections. This study demonstrates how the same activating principles used for decades to make simple C–N (amide) bonds from carboxylic acids with loss of water can be used to make C–C bonds through coupling with dialkylzinc reagents and loss of carbon dioxide. This disconnection strategy benefits from the use of a simple, inexpensive nickel catalyst and exhibits a remarkably broad scope across a range of substrates (>70 examples).

Thoreliolides A and B, two new polyisoprenylated benzoylphloroglucinol derivatives with a novel carbon skeleton, together with four known compounds, were isolated from the fruits of Calophyllum thorelii and their structures elucidated using spectroscopic methods. Thoreliolide B showed moderate activity against three cancer cell lines, MCF-7, HeLa and NCI-H460, with IC 50 values of 9.7, 16.6 and 24.2 μg/mL, respectively, using the sulforhodamine B assay.

We report herein a simple, metal- and additive-free, photoinduced borylation of haloarenes, including electron-rich fluoroarenes, as well as arylammonium salts directly to boronic acids. This borylation method has a broad scope and functional group tolerance. We show that it can be further extended to boronic esters and carried out on gram scale as well as under flow conditions.

Studies on selective hydrogenation of dienic and acetylenic hydrocarbons and their derivatives on metal-containing catalysts are reviewed. The review covers publications over a wide period of time and concentrates on the fundamental principles of catalyst operation. The catalysts modified in the surface layer were shown to be promising for selective hydrogenation.

High quality single crystals with sizes up to 2—3 mm/edge of the transition metal vanadates (Va—g) are hydrothermally prepared and their structures are determined by single crystal XRD.

Evaporative co-crystallization of MCl (M: Na, K, Rb, Cs) with BiOCl in aqueous HCl and various molar ratios yields the double salts MxBiyCl(x+3y)·zH2O.

The cyclization of sulfonamides (I) with s-trioxane proceeds with high regioselectivity toward C1 of the naphthalene ring, while cyclization of the 1-bromo derivative (IV) is directed toward C3.

Two new compounds 1 and 2 have been isolated along with a known compound 3 from both Ficus pomifera Wall and Curcuma leucorrhiza Roxb. The compound 1 is a cyclopentane derivative, 5-(3,4,5,6-tetrahydroxyhexan-2ylidene)cyclopentane-1,2,3,4-tetraol; compound 2 is a natural polymer compound and compound 3 is β-sitosterol glucoside. The similarity of compound 1 has been studied by Reversed Phase-High Performance Liquid Chromatography (RP-HPLC). The compounds 2 and 3 have further been identified by comparison with spectral data. The compound 1 has been tested for anti-microbial and antioxidant activities. The isolation of compound 1, 2 and 3 have been reported from different plants of different families-Moraceae and Zingiberaceae for the first time.

A Pfitzinger reaction of isatin with 2-methyl-(4-oxopent-2-yl)dialkyl(diphenyl)phosphine oxides was used to synthesize new derivatives of 4-quinolinecarboxylic acids, containing a phosphine oxide fragment, and screening for antimicrobial activity was performed.

The compound Cr4US8 has been synthesized at 1073 K and its crystal structure has been determined at 100 K. The structure is modulated with a two-fold commensurate supercell. The subcell may be indexed in an orthorhombic cell but weak supercell reflections lead to the monoclinic superspace group P21/c(α0γ)0s with two Cr sites, one U site, and four S sites. The structure comprises a three-dimensional framework of CrS6 octahedra with channels that are partially occupied by U atoms. Each U atom in these channels is coordinated by eight S atoms in a bicapped trigonal-prismatic arrangement. The magnetic behavior of Cr4US8 is complex. At temperatures above ~120 K at all measured fields, there is little difference between field-cooled and zero field-cooled data and χ(T) decreases monotonously with temperature, which is reminiscent of the Curie–Weiss law. At lower temperatures, the temperature dependence of χ(T) is complex and strongly dependent on the magnetic field strength.

3-Thia-1-dethiazephams (II) are synthesized in high regio- and stereoselectivity via iodocyclization reaction of alkene-thioureas (I).

A simple and efficient process for an exclusive mono-Michael addition of active methylene compounds to conjugated esters, nitriles and ketones is developed. An ionic liquid-mediated reaction is carried out at room temperature. A reaction carried out at 60 °C resulted in a double-addition product. A mechanism is proposed and supported by P31 and DOSY NMR analysis of the used ionic liquid.

Melamine trisulfonic acid (MTSA) as a highly efficient heterogeneous solid acid catalyst catalyzes various organic transformations. The great efforts have been made by many scientists to utilize MTSA as a green catalyst for the preparations of N- and O-containing heterocyclic compounds, for the protections of alcohol, phenols, amines and aldehydes and ketones, for the acetylation of alcohols and phenols and for the N-formylation of amines. The superior advantage of this heterogeneous catalyst is that it can be recovered and reused several times without the loss of their efficiency. In this review, preparation and applications of MTSA in organic synthesis are investigated.

α,α-Difluoro-substituted organozinc reagents generated from conventional organozinc compounds and difluorocarbene couple with 1-bromoalkynes affording gem-difluorinated alkynes. The cross-coupling proceeds in the presence of catalytic amounts of copper iodide in dimethylformamide under ligand-free conditions.

This study describes a simple and efficient procedure to synthesize a series of benzene-fluorinated 2,2-dimethyl-2,3-dihydro-1 H -quinolin-4-ones by the PTSA-catalyzed cyclocondensation reaction of the corresponding ortho -alkynylanilines prepared by the Sonogashira reaction of fluoro-substituted 2-iodanilines with 2-methylbut-3-yn-2-ol. The photofluorescent properties (shape of bands, λ ex , λ em , Stokes shift) of the new compounds were investigated. It has been revealed that the 2,3-dihydroquinolinones with different number of fluoro-substituents have almost the same fluorescence properties. The cytotoxicity evaluation of the 2,3-dihydroquinolinones against human myeloma, human mammary adenocarcinoma, human hepatocellular carcinoma HepG2 epithelial tumor cells, normal mouse fibroblasts and Chinese hamster Ag 17 cells was performed. It has been found that the benzo-perfluorinated derivatives of 2,2-dimethyl-2,3-dihydro-1 H -quinolin-4-ones show enhanced cytotoxic effect against the tumor RPMI (human myeloma) cells line compared with the normal cells. Mutagenic and antioxidant properties of the compounds using Salmonella tester strain were studied. It has been shown, that the compounds are well antioxidants.

Hydrogen sulfide (H2S) is now recognized as an important biological molecule that plays diverse roles in various (patho)physiological conditions. Endogenous H2S, or its misregulation, has been associated with a variety of aspects of human health, including diabetes, hypertension, atherosclerosis, inflammation, neurodegeneration, sepsis, and asthma. Motivated by the potential use of H2S-donating molecules as both investigative and therapeutic tools, researchers are developing new types of slow-releasing H2S donor molecules that mimic the slow, continuous H2S release characteristic of enzymatic production. In addition to synthetic H2S donors, many natural products contain functional groups well known to release sulfide. Here we provide an overview of natural products that contain such functional groups, with an emphasis on organic polysulfides, to highlight the diversity of these structures and also to outline possible areas of future research on pharmacologically relevant H2S donors derived from natural products. 1 Introduction 2 Polysulfide-Containing Natural Products 2.1 Linear Polysulfides 2.2 Cyclic Polysulfides 2.3 Epidithiodioxopiperazines 2.4 Enediyne-Containing Trisulfides 3 Leinamycin 4 Other Disulfides and Thiols Implicated in Hydrogen Sulfide Generation 5 Conclusions and Prospects

A unique possibility for a simple strain tolerant inorganic solid is envisioned whereby a set of isolated, one-dimensional (1D) nano objects are embedded in an elastically soft three-dimensional (3D) atomic matrix thus forming an interdimensional hybrid structure (IDHS). We predict theoretically that the concerted rotation of 1D nano objects could allow such IDHSs to tolerate large strain values with impunity. Searching theoretically among the 1:1:1 ABX compounds of I-I-VI composition, we identified, via first-principles thermodynamic theory, RbCuTe, which is a previously unreported but now predicted-to-be-stable compound in the MgSrSi-type structure, in space group Pnma. The predicted structure of RbCuTe consists of ribbons of copper and telluride atoms placed antipolar to one another throughout the lattice with rubidium atoms acting as a matrix. A novel synthetic adaptation utilizing liquid rubidium and vacuum annealing of the mixed elemental reagents in fused silica tubes as well as in situ (performed at the Advanced Photon Source) and ex situ structure determination confirmed the stability and predicted structure of RbCuTe. First-principles calculations then showed that the application of up to ∼30% uniaxial strain on the ground-state structure result in a buildup of internal stress not exceeding 0.5 GPa. The increase in total energy is 15-fold smaller than what is obtained for the same RbCuTe material but in structures having a contiguous set of 3D chemical bonds spanning the entire crystal. Furthermore, electronic structure calculations revealed that the HOMO is a 1D energy band localized on the CuTe ribbons and that the 1D insulating band structure is also resilient to such large strains. This combined theory and experiment study reveals a new type of strain tolerant inorganic material.

Pb2BiS2I3 (I), Sn2BiS2I3 (II), and Sn2BiSI5 (III) are prepared by solid state reaction of stoichiometric amounts of PbS and BiI3 for (I) (silica tube, 500 °C, 72 h; ≈90% yield) and from a 2:1:2:3.15 molar mixture of Sn, Bi, S, and I2 for mainly (II) and minor amounts of (III) (evacuated silica tubes, 500 °C, 24 h).

Detailed in this Communication is the enantioselective synthesis of 1,1-diarylalkanes, a structure found in a range of pharmaceutical drug agents and natural products, through the employment of copper(I) hydride and palladium catalysis. Judicious choice of ligand for both Cu and Pd enabled this hydroarylation protocol to work for an extensive array of aryl bromides and styrenes, including β-substituted vinylarenes and six-membered heterocycles, under relatively mild conditions.

N-Propargylamines are one of the most useful and versatile building blocks in organic synthesis that are successfully transformed into many significant N-heterocycles. Due to high atom economy and shorter synthetic routes, the synthesis of 1,4-oxazepane and 1,4-diazepane cores from N-propargylamines have undergone an explosive growth in recent years. This review gives an overview of new developments in the synthesis of the title compounds from N-propargylamines in recent years. Mechanistic aspects of the reactions are considered and discussed in detail.

A rapid and straightforward synthesis of the new and highly reactive reagent N-methoxy-N-methylcyanoformamide from trimethylsilyl cyanide and N-methoxy-N-methylcarbamoylimidazole, is reported. This reagent enables the one-pot preparation of β-carbonyl Weinreb amides from lithium enolates, one-carbon homologated Weinreb amides, and unsymmetrical ketones in one-pot procedures from various organometallic species.

Promising levels of enantiocontrol are observed in the silanediol-catalyzed addition of silyl ketene acetals to benzopyrylium triflates. This rare example of enantioselective, intermolecular chromenone functionalization with carbonyl-containing nucleophiles has potential applications in the synthesis of bioactive chromanones and tetrahydroxanthones.

Indole (II) and 1-methylindole (VII) react with 1-arylnitrosoethylene leading to intermediate hetero-Diels—Alder cycloadducts, which suffer an 1,2-oxazine ring-opening reaction to form 3-alkylated indoles.

The cyclopenta[b]indole motif is present in several natural and synthetic biologically active compounds, being directly responsible for the biological effects some of them present. We described herein a three step sequence for the synthesis of cyclopenta[b]indoles with a great structural diversity. The method is based on an oxidative Michael addition of suitable indoles on the double bond of Morita–Baylis–Hillman adducts mediated by a hypervalent iodine reagent (IBX) to form β-ketoesters, which were chemoselectively reduced with NaBH4 in THF to give the corresponding β-hydroxy-esters. The diastereoisomeric mixture was then treated with a catalytic amount of triflic acid (20 mol %) to give cyclopenta[b]indoles with overall yields ranging from 8 to 73% (for 2 steps). The acid-catalyzed cyclization step gave the required heterocycles, via an intramolecular Friedel–Crafts reaction, with high diastereoselectivity, where only the trans product was observed. A mechanistic study monitored by ESI-(+)-MS was also c...

A concise, facile and straightforward synthetic protocol has been described for the preparation of 6-amino-1,4dihydropyrano[2,3-c]-pyrazole-5-carbonitrile derivatives by a one-pot, three-component reaction of ethyl acetoacetate, hydrazine hydrate, aryl aldehydes and malononitrile in glycerol as a green and reusable reaction media under catalyst free condition. The corresponding 6-amino-1,4-dihydropyrano[2,3-c]-pyrazole-5-carbonitriles have been obtained with good to excellent yields (86-92%). This protocol is highly efficient due to its mild reaction conditions, operational simplicity, use of inexpensive, eco-friendly and green reaction media, catalyst-free conditions and absence of toxic organic solvents.

Chiral cyclopentyl β-amino esters are formed catalytically by [3+2] cycloaddition reactions of enecarbamates with electrophilic metalloenolcarbenes in high yield with up to 98 % ee and excellent diastereocontrol. Use of β-silyl-substituted enoldiazoacetates with a chiral dirhodium catalyst and trans-β-arylvinylcarbamates are optimal for this transformation, which occurs with hydrogen-bond association between the vinylcarbamate and the intermediate metalloenolcarbene. Reductive conversion of the protected amino esters forms highly functionalized cyclopentyl β-amino acids and 3-aminocyclopentanones.

A method for the palladium-catalyzed arylation of α,β-unsaturated valerolactams is reported. This new protocol provides arylation products in yields up to 95% and is applicable to a wide array of aryl and heteroaryl bromides. The optimization, scope and limitations are described.

An efficient green method for the selective synthesis of new 4,5-disubstituted 1H-1,2,3-triazoloalkylidenes via the β-cyclodextrin-catalyzed three-component reaction between substituted propynals, trimethylsilyl azide and malononitrile in water at room temperature has been developed.

This paper presents an overview of research pertaining to solid acid catalysts for esterification reactions. Prominence has been given to the literatures that have been appeared during the last two decades. A variety of reactions catalyzed by solid acid catalysts have been tabulated according to their broad classification; industrially important reactions have been outlined. Examples, where the use of various solid acid catalysts have led to an improvement in the selectivity of the desired products, have also been discussed. Various catalyzed esterification reactions using different approaches and previous kinetic studies have been reviewed. Types, preparation and synthesis of various solid acid catalysts have been reviewed and discussed. Suggestions have been summarized for their implementation in future work.

A route towards pyrrolo[2,1-a]isoquinolines through a 3CR of 1-aroyl dihydroisoquinolines, activated alkynes and alcohols has been developed.

It was established here that cross-coupling of polyfluorinated 2-iodoanilines with arylacetylenes in MeCN in the presence catalytic amounts of Pd(PPh3)2Cl2, CuI and Et3N produces the corresponding 2-aminotolans although their yields are decreased from 98% to 40% with increasing fluorination of the substrates. It was shown that the 2-aminotolans with six or fewer fluorine atoms in their rings can be heterocyclised by heating in ethanol containing p-TSA to produce the corresponding polyfluorinated indoles. Cyclisation of tolans containing larger numbers of fluorine atoms in their rings proceeds most efficiently in the presence of KOH, resulting in 2-phenylindoles containing the current maximum of eight fluorine atoms.

It has been more than 50 years since the first phospho-aldol reactions of dialkyl phosphites were reported. These efficient P–C bond-forming reactions have become the cornerstone of methods for the synthesis of α-hydroxyphosphonates and, by numerous available substitution reactions, the synthesis of other α- and γ-substituted phosphonates and phosphonic acids. Much of the interest in α- and γ-substituted phosphonates and phosphonic acids has been stimulated by reports of their biological activity, which is often dependent upon their absolute and relative stereochemistry. In this chapter, we review diastereoselective and enantioselective additions of dialkyl phosphites to aldehydes and ketones, otherwise called the phospho-aldol, Pudovik or Abramov reactions.

The development of photoredox reactions of aryloxy-amides for the generation of amidyl radicals and their use in hydroamination–cyclization and N-arylation reactions is reported. Owing to the ease of single-electron-transfer reduction of the aryloxy-amides, the organic dye eosin Y was used as the photoredox catalyst, which results in fully transition-metal-free processes. These transformations exhibit a broad scope, are tolerant to several important functionalities, and have been used in the late-stage modification of complex and high-value N-containing molecules.

Eosin Y, an organic dye, was activated as a photoredox catalyst in the presence of molecular oxygen using visible light and, when it was used in the reaction of aryl ketones and benzyl amines, afforded good yields (52–87%) of 2,4,6-triarylpyridines (21 examples) at ambient temperature. The aryl groups at the 2- and 6-positions are derived from ketones, while benzyl amine plays the dual role of providing an aryl functionality at the 4-position of pyridine as well as being a nitrogen donor.

The garnet-type solid-state electrolyte Li6.85La2.9Ca0.1Zr1.75 Nb0.25O12 is prepared by calcination of LiOH, La2O3, CaCO3, ZrO2, and Nb2O5 in air (900 °C, 10 h) followed by pelletizing and further annealing at 1050 °C (12 h).