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The binding properties of electron-rich M4L2 metallacages with different cavity sizes, constructed through coordination-driven self-assembly of extended tetrathiafulvalene (exTTF)-based ligands, are evaluated and show a high size selectivity for different guest molecules.

The dorsal horn (DH) neurons of the spinal cord play a critical role in nociceptive input integration and processing in the central nervous system. Engaged neuronal classes and cell-specific excitability shape nociceptive computation within the DH. The DH hyperexcitability (central sensitisation) has been considered a fundamental mechanism in mediating nociceptive hypersensitivity, with the proven role of Ca2+-permeable AMPA receptors (AMPARs). However, whether and how the DH hyperexcitability relates to changes in action potential (AP) parameters in DH neurons and if Ca2+-permeable AMPARs contribute to these changes remain unknown. We examined the cell-class heterogeneity of APs generated by DH neurons in inflammatory pain conditions to address these. Inflammatory-induced peripheral hypersensitivity increased DH neuronal excitability. We found changes in the AP threshold and amplitude but not kinetics (spike waveform) in DH neurons generating sustained or initial bursts of firing patterns. In contrast, there were no changes in AP parameters in the DH neurons displaying a single spike firing pattern. Genetic knockdown of the molecular mechanism responsible for the upregulation of Ca2+-permeable AMPARs allowed the recovery of cell-specific AP changes in peripheral inflammation. Selective inhibition of Ca2+-permeable AMPARs in the spinal cord alleviated nociceptive hypersensitivity, both thermal and mechanical modalities, in animals with peripheral inflammation. Thus, Ca2+-permeable AMPARs contribute to shaping APs in DH neurons and nociceptive hypersensitivity. This may represent a neuropathological mechanism in the DH circuits, leading to aberrant signal transfer to other nociceptive pathways.

In this work the influence of the characteristics ofthematerial ofthe striker (cumulative jet or projectile), moving at speeds of 2-10 km/s, on the volume of the resulting crater in a metal target, has been studied. The dependence ofthe crater volume in an aluminum alloy target ofCu-Al, W-Cu-Pb-Al composites, and steel St45 for a PTFE-Cu composite, were investigated. The outer diameter and height of the shaped charges were 26 and 28, and 31 and 33 mm, respectively. The mass of the explosive (phlegmatized hexogen) in these charges was 10 and 18 g. A comparison was made between the ratios of the kinetic energy of the striker to the volume of the crater formed for the composites PTFE-Al, PTFE-Cu, Cu-Al, Ni-Al, W-Cu-Pb, and porous materials Cu and Al. It was demonstrated that the chemical interaction of the components of the porous Cu-Al and Ni-Al composites during penetration into the barrier is possible at an impact velocity of at least 2-3 km/s and a porosity of at least 30%.

The influence of the main parameters on the process of obtaining artificial carnallite and its quality has been established. It is shown that to obtain a product with a high content of the carnallite phase and a low content of bischofite and KCl, it is necessary to use magnesium chloride solution with the concentration of 27-30 % and preheated ground potassium chloride. The process should be carried out at the temperature of 80 °C. The formation of synthetic carnallite, close in composition to the enriched one, occurs when the ratio of potassium chloride to magnesium chloride in the initial mixture is equal or close to their stoichiometric ratio in carnallite. With an excess of potassium chloride in the reaction mixture, an increased content of potassium and sodium chlorides in the product is observed, and with its deficiency, the product contains an increased amount of bischofite phase. To reduce the hydrolysis of magnesium chloride during dehydration, a slight excess of potassium chloride should be maintained in the mixture entering the synthesis. It is shown that the most advantageous scheme for producing artificial carnallite provides for incomplete evaporation of desulfurized liquor in the presence of potassium chloride with the return of circulating carnallite liquor to the desulfurization stage.

A convenient methodology for constructing 6,6-difluorospiro[3.3]heptane scaffold – a conformationally restricted isostere of gem-difluorocycloalkanes – is developed. Alarge array of novel 2-mono- and 2,2-bifunctionalized difluorospiro[3.3]heptane building blocks was obtained through the convergent synthesis strategy using a common synthetic precursor – 1,1-bis(bromomethyl)-3,3-difluorocyclobutane. The target compounds and intermediates were prepared by short reaction sequences (6–10 steps) on multigram scale (up to 0.47 kg).

International audience; A M2L2 metalla-macrocycles contructed through coordination driven self-assembly from the Pd(dppf)OTf2 complex (dppf = 1,1′-Bis(diphenylphosphino)ferrocene) and an electron-rich 9-(1,3-dithiol-2-ylidene)fluorene bis-pyridyl ligand is depicted. This molecular tweezer exhibits a cavity able i) to promote dimerization upon oxidation and ii) to bind an electro-deficient substrate with a remarquable association constant. Those properties are compared with those of a previously described regioisomer.

Optimized synthesis of 1-methyltetrazolo[5,1-a]isoindole-derived amides and thioamides was elaborated. Based on 13C NMR spectroscopy and X-Ray diffraction studies data, it was proposed that zwitterionic resonance structures contributed significantly to the structure of these compounds. Geometry optimization was performed in vacuo using m06-2x/cc-pvtz method taking into account polarizing effect of environment (PCM model) and specific intermolecular interactions. Electronic density distribution in these molecules was analyzed using NBO method. Using Δ(HOMOdiene–LUMOdienophile) for amides and thioamides in vacuo and in a protic solvent, possibility of Diels–Alder reaction was evaluated. Energies of π-π conjugation and n→σ* hyperconjugation for the amide derivative were estimated in vacuo, aprotic and protic solvents.

International audience; Phosphorus-containing inherently chiral calix[4]arenes as well as calix[4]arenes substituted with phosphinoferrocene chiral groups at the lower rim are described. Stereoselective synthesis, structure, and catalytic properties of the chiral calixarenes are discussed.

International audience; A M8L2 metalla-cage constructed through coordination-driven self-assembly from a quinonato bis-ruthenium complex and an electron-rich tetrathiafulvalene (TTF) tetrapyridyl ligand is depicted. In this molecular box, both TTF units are highly bent and are separated by a distance as short as 3.48 Å in the solid state. This system offers a unique opportunity to study the electronic interactions occurring between two TTF units facing each other in a conformationally rigid environment.

International audience; The development of methodologies to control on demand and reversibly supramolecular transformations from self-assembled metalla-structures requires the rational design of architectures able to answer to an applied stimulus. While solvent, concentration, guest, light, addition of a chemical have been largely explored to provide these transformations, the case of pH sensitive materials is less described. Herein, we report the first example of a pH-triggered dissociation of a coordination-driven self-assembled interlocked molecular link. It incorporates a pH sensitive benzobisimidazolebased ligand that can be selectively protonated on its bisimidazole moieties. This generates intermolecular electrostatic repulsions that reduces drastically the stability of the interlocked structure, leading to its dissociation without any sign of protonation of the basic pyridine moieties involved in the coordination bonds. Importantly, the dissociation process is reversible through addition of a base.

The Sm-activated orthvanadate nanoparticles with La1-xSmxVO4 (x ≤ 0.3) composition were synthesized by co-precipitation and sol-gel methods. XRD study has shown that synthesized samples are characterized by monoclinic or tetragonal structure as well as their mixture dependently on Sm concentration and methods of synthesis. Influence of method of synthesis on morphology of nanoparticles, their absorption, diffuse reflectance and emission spectra was observed and studied. Luminescence properties and diffuse reflectance spectra of the sol-gel nanoparticles are also depend on Sm concentrations. At least two types of Sm3+ centers were found by emission spectra. These centers have different excitation efficiency by light from the 350–450 nm spectral range. Structures of the centers are discussed taking into account crystal structure, possible defects, morphology of the synthesized nanoparticles and their phase compositions.

1-(Trimethylsilyl)vinyl MIDA boronate — a trifunctional C2 building block — is prepared in only two laboratory steps and 54% overall yield starting from readily available trimethyl(vinyl)silane. The title compound undergoes orthogonal functionalization at either of the groups present in its structure, for example, iodination at the trimethylsilyl moiety, epoxidation at the double bond, and Suzuki–Miyaura coupling at the MIDA boronate.

Eight alkyl triarylstannanecarbodithioates were synthesized starting from the corresponding triarylstannyl chlorides. They were fully characterized by IR and 1 H, 13 C, and 119 Sn NMR spectroscopy and mass spectrometry. Their solid-state structures and geometric parameters were determined and compared to those of other classes of thiocarbonylthio compounds. These new organotin derivatives are efficient reversible chain-transfer agents for reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St) and n-butyl acrylate (BA), with controlled number-average molecular weights and narrow dispersities (Ð

New phosphinoylcarbodithioate RAFT agents bearing dicyclohexyl- and di(piperidin-1-yl)phosphinoyl substituents were prepared, and their activity in RAFT polymerization of styrene and n-butyl acrylate was compared to that of previously reported diphenyl and bis(N,N-diisopropylamino) counterparts. Polymerizations were performed in deuterated solvent with quantitative 31P and 1H NMR monitoring. This approach allowed to study the polymer ω chain-end fidelity as well as RAFT agent transformations during the initialization period. It was also successfully applied for the monitoring of the block copolymerization. RAFT agents with cyclohexyl and piperidin-1-yl substituents bonded to the phosphorus center exhibited a marked improvement in the polymerization control with an optimal compromise between overall kinetics and control over molar masses and dispersities along with a significantly enhanced ω chain-end stability during polymerization.

The synthesis of 2-(methoxymethyl)isoindolin-1-imine derivatives via an unusual Delepine reaction is reported. The substrate substituents’ influence on the reaction course was studied, and a possible reaction mechanism proposed. The structure of 2-(methoxymethyl)isoindolin-1-imine was confirmed by X-ray diffraction analysis.

The Mitsunobu alkylation of 4-tert-butylcalix[4]arene with (S)-(2-diphenylthiophosphinoferrocenyl)methanol followed by desulfuration of the thiophosphine unit using tris(dimethylamino)phosphine afforded enantiomerically pure calixarene mono- and di(ferrocenylphosphine) ligands in high yields. The calixarene mono(ferrocenylphosphine) ligands exhibited good catalytic activity but low atropoenantioselectivity when used in the asymmetric Suzuki–Miyaura coupling reaction of 1-naphthaleneboronic acid and 1-bromo-2-methylnaphthalene. However, the di(ferrocenylphosphine) ligand displayed both good catalytic activity and enantioselectivity (ee values up to 86 %) when employed in the asymmetric Tsuji–Trost allylic alkylation of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate.

For the first time, the tetrazole ring-opening has been observed for tetrazoloisoindoles as an example of azido-tetrazole isomerism. This process was studied in details by HPLC; conditions were found which are optimal for the azido-tetrazole equilibrium. It is shown that the tetrazole ring-opening proceeded with formation of unstable azide intermediate and subsequent extrusion of N2 molecule. Molecular geometry of the tetrazole form and possible unstable azide forms were calculated using M06–2X/cc-pVTZ method in vacuo and taking into account the effect of polarizing environment, and for azide forms – also taking into account specific intermolecular interactions with solvent. Electron density distribution within the tetrazole form was analyzed using Bader’s AIM theory. Resonance structures for azide forms were studied using NBO method. Calculated UV spectra were obtained using CAM-B3LYP/cc-pVTZ methods for all studied molecules.

Two M12 L6 redox-active self-assembled cages constructed from an electron-rich ligand based on the extended tetrathiafulvalene framework (exTTF) and metal complexes with a linear geometry (PdII and AgI ) are depicted. Remarkably, based on a combination of specific structural and electronic features, the polycationic self-assembled AgI coordination cage undergoes a supramolecular transformation upon oxidation into a three-dimensional coordination polymer, that is characterized by X-ray crystallography. This redox-controlled change of the molecular organization results from the drastic conformational modifications accompanying oxidation of the exTTF moiety.

International audience; A facile method for the preparation of enantiomerically pure inherently chiral calix[4]arene phosphonic acid (cR,pR)-7 in four steps starting from the readily available and previously synthesized (cS)-enantiomer of calix[4]arene acetic acid 1 or its methyl ester 2 was developed. The first tests of this unique calixarene Brönsted acid with inherent chirality in organocatalysis of the aza-Diels–Alder reaction of imines with Danishefsky’s diene and epoxide ring opening by benzoic acid were performed. The calixarene phosphonic acid (cR,pR)-7 shows good catalytic activities but with low enantioselectivities in these reactions.

A new series of β-hydroxytriazoles were synthesized and evaluated as Mycobacterium tuberculosis inhibitors. Our strategy implied the synthesis of alkyne precursors through a Barbier reaction between benzaldehydes and propargyl bromide followed by click chemistry to afford substituted β-hydroxyl benzyltriazoles. These compounds are also key intermediates either for oxidation reactions leading to α,β-diketotriazoles or for elimination reactions affording styryl triazoles. Evaluation of all new compounds for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv resulted in compounds with MIC up to 7 μM.

International audience; Two new enantiomerically pure ferrocenyl phenol-thiophosphine compounds have been efficiently synthesized by a one pot procedure from enantiomerically pure alcohol (R)-(diphenylthiophosphinoferrocenyl)methanol 1 by a fully regioselective Friedel-Crafts reaction on phenols after strong acid activation. A mechanistic proposal through O-alkylation followed by rearrangement of the formed oxonium is proposed. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of one of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystal.

The tandem reduction/oxidation of fluorenyl compounds was performed with LiAlH4 under air to afford the corresponding 9-hydroxyfluorenyl derivatives in good yields. This methodology with LiAlH4 is unprecedented and most likely proceeds by an organoaluminium intermediate, and in the proposed mechanism.

C-, N-, and/or O-methylation products were generated from 11H-isoindolo[2,1-a]quinazoline-5-one upon treatment with NaH followed by iodomethane under air, and possible recrystallization from methanol. Two products were fully characterized by NMR and X-ray diffraction analysis. In accordance with the HSAB principle, this soft methylating agent (MeI) leads mainly to the C,C-dimethylated product 11,11-dimethyl-11H-isoindolo[2,1-a]quinazoline-5-one, which was previously not observed, beside the N-methylated product, in a procedure using methyl tosylate as a hard methylating agent of the same substrate in the initial absence of a base. A mechanism is finally proposed for the formation of methyl 2-(3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)benzoate as an oxidation side product.

A series of GEQ analogues bearing pyrrolidinone or pyrrolidine cores were synthesized and evaluated against InhA, essential target for Mycobacterium tuberculosis (M.tb) survival. The compounds were also evaluated against M.tb H37Rv growth. Interestingly, some of the compounds, not efficient as InhA inhibitors, are active against M.tb with MICs up to 1.4 μM. In particular, compound 4b was screened with different M.tb mutated strains in order to identify the cellular target, but without success, suggesting a new possible mode of action.

The preparative methods for the synthesis of imidazolium and pyridinium room temperature task-specific ionic liquids possessing thiacalix[4]arene complexing groups in cationic or anionic fragments of the molecule are described. The cationic imidazolium and pyridinium derivatives of tetrabuthoxythiacalixarene existing in the conformation 1,3-alternate are capable to bind “soft” metal cations due to cooperative cation-π and ion–dipole interactions with spatially contiguous benzene rings and oxygen atoms of the thiacalixarene platform. The cone-shaped imidazolium salts of the tetrahydroxythiacalix[4]arene sulfonic acid can chelate cations of transition metals, lanthanides, and actinides by oxygen and sulfur atoms at the lower rim of macrocycle.

Both enantiomers of inherently chiral dipropoxy-p-tert-butylcalix[4]arene carboxylic acids with AABH substitution patterns have been prepared by the stereoselective reactions of 25,26-dipropoxy-p-tert-butylcalix[4]arene with enantiomerically pure (S)- or (R)-N-(1-phenylethyl)bromoacetamide, separation of the diastereomers by recrystallization, and removal of the chiral auxiliary groups. The absolute configurations of the obtained compounds have been established by X-ray analysis.

International audience; 3-Chloro-2-phenyl-isoindole-1-carbaldehyde has been prepared from N-phenylisoindolinone under Vilsmeier–Hack conditions. This electrophilic isoindole proved to be stable under the basic conditions used in the final treatment (KOH/MeOH), and for weeks under air in the solid state. Nevertheless, the C–Cl bond proved highly sensitive to any treatment with reducing or alkylating agents targeted towards the pendant carbaldehyde group, giving various phthalimide derivatives. This unique reactivity is exploited for the selective synthesis of new aminoisochromanones

Lithium perchlorate has been found to catalyze the conjugate addition of maleimides with 2-aminopyridines and 2-aminothiazoles. The reaction proceeds under mild conditions leading to the corresponding double adducts in good yields. A plausible mechanism of this reaction has been proposed. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications ® to view the free supplemental file.

A novel regio- and diastereospecific ring cleavage of bornane-2,3-dione (camphor quinone) under Bucherer-Bergs reaction conditions has been investigated. The simplicity of this transformation provides a novel and straightforward synthetic pathway to enantiopure derivatives of cyclopentane carboxylic acid as well as functionalized hydantoins in just two steps, starting from inexpensive and easily available camphor.

4-Carboxycamphor, easily obtainable starting from camphor, is used as a versatile precursor in high-yielding syntheses of a wide range of cyclopentanecarboxylic acids using just a few steps. Regioselective bromination of 4-carboxy- and 4-methoxycarbonyl-3-bromocamphors leads to 10-bromomethyl derivatives in good yields. Grob-type fragmentation reactions proceed smoothly for 10-bromocamphor-4-carboxylic acid, 10-bromocamphorquinone-4-carboxylic acid and 3,4-dibromocamphor with the formation of unsaturated cyclopentanecarboxylic acids. Detailed studies of bromination and rearrangement reactions of brominated camphor-4-carboxylic acid and its derivatives, reported herein, highlight the unique chemistry of substituted camphor and offer easy access to a wide range of 2,2-dimethyl-3-methylenecyclopentanecarboxylic acid derivatives.

A novel one-step procedure for the synthesis of 2-substituted-isoindoles and 1-aryl-2-substituted-isoindoles is described. The procedure is based on the reaction of 2-(bromomethyl)benzaldehyde or 2-(bromomethyl)benzophen-one derivatives with primary aromatic or aliphatic amines. Reactions of 1,2-diarylisoindoles with N-phenylmaleimide were studied. Refluxing the reactants in i-PrOH in the presence of triethylamine leads to the formation of Diels–Alder endo-adducts; whilst refluxing in AcOH in the presence of AcONa affords Michael adducts. The structure of the latter was confirmed by X-ray diffraction.

Transient and steady electric currents through a pentyl-cyano-biphenyl nematic liquid crystal cell have been studied under and without external photo-irradiation. The importance of space-charge effects has been demonstrated.

Reaction of ethyl 5-acetyl-3,4-dihydropyridine-1(2 H)-carboxylate with diverse 1,3- N, N-bis-nucleophilesresults in the regioselective formation of the correspondingly substitutedpyrimidines in good yields.

Base- and acid-catalyzed nucleophilic addition of 11H-isoindolo[2,1-a]quinazoline-5-one to aromatic aldehydes and maleimides was investigated. The aldol adducts and condensation products were obtained stereoselectively. Main diastereomers of the Michael adducts were isolated in 74–89% yield, and converted by N-methylation to new stable α-substituted isoindole derivatives, for which 6-methylisoindolo[2,1-a]]quinazoline-5-one stands as the unsubstituted reference. The stability of the latter was monitored in moist aerated CDCl3 solution, and one of the oxidative hydrolysis product was characterized by X-ray diffraction analysis as the corresponding N-arylphthalimide. The reactivity of the unsubstituted 6-methylisoindolo[2,1-a]]quinazoline-5-one was also investigated with acetylenic Michael acceptors. Fully conjugated isoindole derivatives possessing an original pull–push–pull structure were obtained. The conformations and molecular orbitals of the dibenzoylacetylene adduct were studied at the DFT level of theory. Its static quadratic hyperpolarizabilty β0 was also calculated at the ZINDO level.

The reaction of ethyl 5-acetyl-3,4-dihydropyridine-1(2 H)-carboxylate with diverse aliphaticas well as aromatic monosubstituted hydrazines resulted in the regioselectiveformation of N-substituted 3-methylpyrazoles.

Foaming and stabilizing capacities of sodium salts of carboxylic acids (lauric, myristic, palmitic) in the presence of aliphatic alcohols (hexanol, butanol) and inorganic electrolytes was studied.

Based on the spectral studies of 1-aminoisoindole we have observed that in solution the isoindolenine tautomer predominates. In spite of this fact but, taking into account the Curtin–Hammett principle, we undertaken the first study of the Diels–Alder reaction for 1-aminoisoindole as a typical representative of simple isoindoles in isoindoline form. We have studied the interaction of 1-aminoisoindole with maleimide derivates and demonstrated that the products are rearranged 1:2 composition adducts. We have proposed a rearrangement mechanism, detected and identified the intermediate Diels–Alder products containing both endo- and exo adducts.

The reaction of the isoindole–isoindoline isomers of the thieno[3′,2′:5,6]pyrimido[2,1-a]isoindol-6(10H)-one with aldehydes gives new benzylidene thieno[3′,2′:5,6]pyrimido[2,1-a]isoindol-6(10H)-one derivatives. The structures were assessed with NMR, UV spectroscopy and mass spectra.

Formation of R1R2 associates between hexadecylammonium chloride and sodium carboxylates (octanoate, laurate, and palmitate) was studied by IR spectroscopy and chemical methods, and their foaming activity was characterized.

Data on methods for the synthesis of isoindolo[2,1-a]benzimidazole and its derivatives and their chemical characteristics are reviewed. Data from quantum-chemical calculations of certain structures are presented. Possible practical applications of the compounds are indicated.

meso-Substituted symmetrical monomethine cyanine dyes derived from the triazoloisoindole were obtained by reaction of 2-R-5H-[1,2,4]triazolo[5,1-a]isoindoles with acyl chlorides. The meso group can be varied in a wide range enhancing the interest of these dyes like biological probes. Spectral UV–vis properties are reported.

A new range of tin-based reversible addition–fragmentation chain-transfer (RAFT) agents is described and evaluated for the polymerization of acrylamides, methyl acrylate and styrene. These organometallic compounds are highly reactive reversible transfer agents which allow an efficient control of the polymerization of substituted acrylamide monomers, whereas RAFT control for methyl acrylate and styrene polymerization is contaminated by side reactions at prolonged reaction times. 119Sn NMR is shown to be an informative instrument for the monitoring of Sn-RAFT-mediated polymerizations.