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The metastable (at 25 °C) high-temperature phase of BaGe3 (tetragonal CaGe3-type structure, space group I4/mmm, Z = 8, powder XRD) is obtained by hot press sintering of arc melted precursor samples using 1% Ba excess for loss compensation (multi anvil press, 15 GPa, 1300 K).

The hexagonal modification hP8 of EuGe3 is obtained by arc-melting of a stoichiometric mixture of the elements (1% excess of Eu) followed by high-pressure sintering (multianvil press, 12 GPa, 1100 K, 1 h).

Plate-shaped single crystals of tetragonal β-Fe1.00Se are grown from polycrystalline material by chemical vapor transport with AlCl3 as transport additive (evacuated quartz ampoule, temp.

This review provides a detailed overview about the synthesis, properties and applications of all ruthenium-fullerene compounds reported within the last 25 years. The incorporation of ruthenium centers into fullerene compounds by organometallic, covalent or non-covalent bonds has led to a broad range of useful hybrid materials. By this approach novel compounds could be generated that feature the electron-donating and electron-accepting character of ruthenium complexes and fullerenes, respectively. Intramolecular interactions between both units could result in new, combined properties that were studied in the spotlight of emerging applications, such as photovoltaics or catalysis.

The incorporation of metal centers into the backbone of polymers has led to the development of a broad range of organometallic and coordination compounds featuring properties that are relevant for potential applications in diverse areas of research, ranging from energy storage/conversion to bioactive or self-healing materials. In this review, the basic concepts and synthetic strategies leading to these types of materials as well as the scope of available characterization techniques will be summarized and discussed.

A versatile one-step two-component cyclization to build new tetracyclic nitrogen heterocycles is described. Ortho-methylhetarenecarbonitrile components were condensed with aldehydes to access a large library of differently substituted ring systems. The heterocyclic core can be easily modified by variation of the position of the endocyclic nitrogen atom in the o-methylhetarenecarbonitrile substrate. The manner of the nucleophilic attack that leads to the condensation can be triggered by different electron-density distribution in the molecule induced by the position of the nitrogen atom. Taking this into account, there is an electronic preference that leads to either pyridophenanthrolines or the corresponding pyridoazacarbazoles as the main products. We demonstrate the high antitumor potential of some of our synthesized heterocycles, which is strongly dependent on the substitution pattern introduced through the aldehyde component. The position and number of endocyclic nitrogen atoms play an important role regarding cytotoxicity of the studied compounds.

The title triazole derivatives are prepared from thiosemicarbazide and aliphatic aldehydes via formation and intramoleculare cyclization of thiosemicarbazone in good yields.

Bulk high-throughput experiments allow the exploration of unknown alloy systems for novel permanent magnet phases. This multilevel concept is threefold. Search field prioritization is based on physical, technological, and economic aspects to identify promising systems in advance. Efficient synthesis is based on heterogeneous nonequilibrium states to scan the most interesting part of the phase diagram of one alloy system by one sample. An efficient analysis is based on the characteristic domain structure of hard magnetic phases to evaluate the magnetic properties and industrial relevance of the novel phases. The efficiency of the elaborate concept is demonstrated for the well-known ternary system Fe-Nd-B and then applied to discover novel phases for permanent magnets.

Copper(I) and copper(II) complexes were covalently linked to an engineered variant of the transmembrane protein Ferric hydroxamate uptake protein component A (FhuA ΔCVFtev). Copper(I) was incorporated using an N-heterocyclic carbene (NHC) ligand equipped with a maleimide group on the side arm at the imidazole nitrogen. Copper(II) was attached by coordination to a terpyridyl ligand. The spacer length was varied in the back of the ligand framework. These biohybrid catalysts were shown to be active in the Diels–Alder reaction of a chalcone derivative with cyclopentadiene to preferentially give the endo product.

26 Title compounds are prepared and preliminarily screened for their in vitro urease inhibition and antifungal activity.

Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine.

Thyroid hormones (THs) are secreted by the thyroid gland. They control lipid, carbohydrate, and protein metabolism, heart rate, neural development, as well as cardiovascular, renal, and brain functions. The thyroid gland mainly produces l-thyroxine (T4) as a prohormone, and 5'-deiodination of T4 by iodothyronine deiodinases generates the nuclear receptor binding hormone T3. In this Review, we discuss the basic aspects of the chemistry and biology as well as recent advances in the biosynthesis of THs in the thyroid gland, plasma transport, and internalization of THs in their target organs, in addition to the deiodination and various other enzyme-mediated metabolic pathways of THs. We also discuss thyroid hormone receptors and their mechanism of action to regulate gene expression, as well as various thyroid-related disorders and the available treatments.

Solution-phase catalysis using molecular transition metal complexes is an extremely powerful tool for chemical synthesis and a key technology for sustainable manufacturing. However, as the reaction complexity and thermal sensitivity of the catalytic system increase, engineering challenges associated with product separation and catalyst recovery can override the value of the product. This persistent downstream issue often renders industrial exploitation of homogeneous catalysis uneconomical despite impressive batch performance of the catalyst. In this regard, continuous-flow systems that allow steady-state homogeneous turnover in a stationary liquid phase while at the same time effecting integrated product separation at mild process temperatures represent a particularly attractive scenario. While continuous-flow processing is a standard procedure for large volume manufacturing, capitalizing on its potential in the realm of the molecular complexity of organic synthesis is still an emerging area that requires innovative solutions. Here we highlight some recent developments which have succeeded in realizing such systems by the combination of near- and supercritical fluids with homogeneous catalysts in supported liquid phases. The cases discussed exemplify how all three levels of continuous-flow homogeneous catalysis (catalyst system, separation strategy, process scheme) must be matched to locate viable process conditions.

A three-step approach to enantiomerically pure 3-aminoseptanoside derivatives by addition of lithiated methoxyallene to δ-silylated aldopentose-derived nitrones, followed by Bronsted acid mediated cyclization and chemoselective N–O bond scission is presented. For the addition of the methoxyallene anion leading to 3,6-dihydro-1,2-oxazines, excellent syn-diastereoselectivities were observed in the case of d -xylose- and l -arabinose-derived nitrones, whereas the d -ribose analogue provided syn- and anti-configured products in an approximately 2:1 ratio. Subsequent proton-induced reactions provided the corresponding dimethyl ketals as kinetic products, which slowly converted into bicyclic oxepanoides formed in a highly cis-selective manner. The final reductive ring opening was performed in good yields by using an excess of samarium(II) iodide. With a selected compound it was demonstrated that this type of product is a suitable precursor for the preparation of polyfunctionalized oxepanopyrrolidine derivatives.

The scope of a flexible route to unsymmetrically functionalized bipyridines is described. Starting from 1,3-diketones 1a–e, the corresponding β-ketoenamines 2a–e were converted into different β-ketoenamides 3a–g by N-acylation with 2-pyridinecarboxylic acid derivatives. These β-ketoenamides were treated with a mixture of TMSOTf and Hunig’s base to promote the cyclocondensation to 4-hydroxypyridine derivatives. Their immediate O-nonaflation employing nonafluorobutanesulfonyl fluoride provided the expected 4-nonafloxy-substituted bipyridine derivatives 5a–g in moderate to good overall yields. The bipyridyl nonaflates are excellent precursors for palladium-catalyzed reactions as demonstrated by representative Suzuki and Sonogashira couplings. Thus, a library of specifically substituted bipyridine derivatives was generated, showing the versatility of the simple 1,3-diketone-based approach to this important class of ligands.

The two isomeric compounds K1.5(Me2NH2)8.5 [anti-PtII2 (α-PW11O39)2]·28H2O (I) and K1.5(Me2NH2)8.5 [syn-PtII2 (α-PW11O39)2]·18H2O (II) are obtained from an aqueous mixture of K7[α-PW11O39], K2PtCl4, and HCl (pH 4.0, 80 °C, 18—20 h) followed by addition of Me2NH2Cl (15 and 5% yield for (I) and (II), respectively).

A ternary boride Ga 2 Ni 21 B 20 , with modified Zn 2 Ni 21 B 20 -type structure (space group I 4/ mmm , and lattice parameters a = 7.2164(1) A, c = 14.2715(4) A), was synthesized from the constituent elements. Single crystal diffraction data reveal Ni at 8 f site splitting into 16 m position with nearly half occupancy. In this structure, [Ni 6 B 20 ] cages share ligand boron atoms with [Ga 2 B 4 Ni 9 ] hexa-capped square prisms, forming two dimensional layers. Layers are interconnected via Ga−Ni interactions and build up a three-dimensional framework. Quasi-two-dimensional infinite planar nets formed by intercrossed Ni atoms are embedded. Ga 2 Ni 21 B 20 is a metallic Pauli paramagnet, in agreement with electronic structure calculations, resulting in 8.2 states eV −1 f.u −1 at the Fermi level.

Bioactive low-molecular-weight compounds are actively pursued, as an alternative to macromolecules, for biomedical applications such as drug and gene delivery. However, achieving effective biomolecular surface recognition with small molecules is a considerable challenge. We review herein recent progresses that have been made in the identification of bioactive cationic clusters that promote cell penetration and nucleic acid complexation and vectorisation. We further emphasize the emerging use of self-assembly processes, based on supramolecular interactions and/or dynamic covalent chemistry, for generating bioactive cationic clusters. Interestingly, the introduction of molecular and/or supramolecular dynamics endows reversibility to the multivalent recognition processes, thereby paving the way toward the development of "smart" adaptive and responsive devices that emulate the behaviour of natural systems for the dynamic control of bioactivity.

The cyclization of N-acylated indole derivative (I) proceeds readily in the presence of SmI2 and LiBr in water/THF.

γ-Aryl-β-ketoesters can be prepared in one step from aryl bromides and bis(trimethylsilyl) enol ethers using catalytic amounts of Pd(dba)2/t-Bu3P and stoichiometric amounts of Bu3SnF. The wide range of γ-(hetero)aryl-β-ketoesters that can be obtained illustrate the scope and limitations of this novel Hauser-Heck combination. γ-Aryl-β-ketoesters with a 1,3-dioxane acetal in the ortho position can easily be transformed into the hydroxy naphthoate in very good yield. Aqueous formic acid at 65 °C provides optimal conditions for this deprotective aromatization.

The new borides AlNi9B8 (I) and GaNi9B8 (II) are prepared by arc melting of the elements with a 5% excess of Ga for loss compensation followed by annealing (alumina crucibles in evacuated quartz tubes, 920 °C (I) or 895 °C (II), 7 d).

Single crystals of Na39[{Na(H2O)6} Eu12(OH)12(H2O)18Ge2 (GeW10O38)6]·159H2O (I), Na37[{Na(H2O)6} Gd12(OH)6(H2O)24Ge (GeW10O38)6]·129H2O (II), and Na36 [{(H2O)6}Dy12(H2O)24 (GeW10O38)6]·122H2O (III) are prepared by slow crystallization from a solution containing equimolar amounts of LnCl3 (Ln: Eu, Gd, Dy) and Na10[α-GeW9O34] and NaCl at pH 5 (50 °C, 30 min; 23%, 20%, and 21% yield, resp.).

Compounds (IV) and (VII) are characterized in the solid state by single crystal XRD and FTIR spectroscopy, and in solution by UV/VIS and NMR spectroscopy and electrochemical measurements.

Strychnine stands out from the group of classical natural products as one of the first complex compounds to be isolated in pure form and an extreme challenge to be structurally characterized. It has played a central role in natural product total syntheses and the surge in the development of innovative synthetic methods for many decades. Recently, we have accomplished one of the shortest formal total syntheses of strychnine (in ten steps and 14% overall yield or even shorter in eight steps and 10% overall yield). The evolution of a productive synthetic strategy, as well as the synthetic challenges tackled, are described here in detail, including examples of related transformations. The successful synthetic strategy was inspired by the premise that the core structure could be derived from simple aromatic indole precursors by a reductive SmI2 -induced ketyl-aryl coupling. Other key reactions included a diastereoselective reduction and a regioselective elimination protocol. Altogether one of the shortest syntheses of iso-strychnine and hence of strychnine was established.

Multivalent nanoconstructs, extensively used for enhancing the recognition of biomolecular targets, have been recently exploited for enzyme inhibition showing interesting properties such as improvement of inhibitory potency and selectivity. We review herein the recent results highlighting the potential of multivalent nanoconstructs for the inhibition of different enzymes, and the emerging trends in the generation and identification of multivalent clusters as enzyme inhibitors.

This comprehensive report accounts the development of a highly diastereoselective samarium diiodide-induced cascade reaction of substituted indolyl ketones. The complexity-generating transformation with SmI2 allows the diastereoselective generation of three stereogenic centers including one quaternary center in one step. The obtained tetra- or pentacyclic dihydroindole derivatives are structural motifs of many monoterpene indole alkaloids, and their subsequent transformations gave way to one of the shortest approaches towards strychnine (14 % overall yield in ten steps, or 10 % overall yield in eight steps). During the course of this report we discuss the influence of substituents on the cyclization step, plausible mechanistic scenarios for the SmI2 -induced cascade reaction, diastereoselective reductive amination, and regioselective dehydratization protocols towards the pentacyclic core structure of strychnos alkaloids.

Ba[CoSO] is prepared by the reaction of equimolar amounts of BaO, Co, and S (corundum crucible in evacuated silica tubes, 1.

Compounds (III), (VIII), and (XII) are characterized by single crystal XRD, IR spectroscopy, magnetic susceptibility measurements, and electrochemical measurements.

The crystal and electronic structure, chemical bonding, and physical properties of ThPt2 are characterized by powder XRD, magnetic, electrical resistivity and specific heat measurements, and by DFT scalar-relativistic electronic structure calculations.