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A convenient approach to 2-(1-ethoxyalkoxy)-3-cyanoquinolines (in up to 50% yields) has been developed. The approach comprises functionalization of quinolines with acetals of cyanopropargylic alcohols (KOH/H2O/MeCN, 55-60 °C) followed by their transformation to furo[3,4-b]quinolinones (in up to 98% yields) via the sequential removal of acetal protection and intramolecular cyclization/hydration (7% aqueous HCl, acetone, 20-25 °C).

The paper deals with a comparative study of equilibrium and kinetics of phenol adsorption from aqueous solutions by means of commercial activated carbons and semi-cokes, differing in the nature of feedstock, production technology and structural characteristics. The main adsorption parameters are calculated with the usage of Langmuir and Dubinin–Radushkevich equations. The change in the characteristics of the structure and state of the surface of semi-coke P2 as a result of modification is estimated. It was found that phenol adsorption kinetics is described by a pseudo-second-order model. The adsorption rate constants and the coefficient of external diffusion mass transfer are calculated. It is proved that phenol extraction from aqueous solutions presents a mixed-diffusion nature, and the process rate is limited by external mass transfer for 13 min for SKD-515 and 22 min for ABG. To increase the adsorption capacity, the oxidative modification of the semi-coke P2 was carried out. Considering the economic and technological aspects, ABG semi-coke is recognized as a promising sorbent for phenol extraction from aqueous media.

Catalyst systems based on gold nanoparticles introduced into the matrices of mesoporous metal–organic frameworks of the MIL type based on trivalent metal ions (Al, Fe) manifest activity in the regioselective hydroamination of phenylacetylene with aniline according to the Markovnikov rule. The activity of the synthesized gold-containing systems significantly depends on the nature of organic and inorganic building units, metal ions, and organic linkers, which form the framework, as well as on the catalyst preparation procedure.

The reaction of quinolines with CF3-ynones resulted in the formation of 1,3-oxazinoquinolines. Subsequent treatment of the reaction mixture with a base initiated deep structural transformation of p...

The conformational isomerism and orbital interactions of N-(2-bromo-2-phenylethenyl)-N,N-bis(trimethylsilyl)amine and N-(2-bromo-2-trimethylsilylethenyl)-N,N-bis(trimethylsilyl) amine were examined using NMR technique and quantum-chemical calculations. The IR criterion characterizing σ→σ* hyperconjugation is considered, and the linear dependence of σC–H→σ*C–X (X = F, Cl, Br) interaction energy on the polarizability of X is discussed.

We studied trichloroethylene (TCE) adsorption from aqueous solutions in equilibrium conditions by activated carbons (AC). They differ in raw materials, porous structure characteristics and chemical state of the surface. TCE adsorption isotherms were found to have a concave shape, which is characteristic of a sorbent—sorbate weak interaction. It can be a result from electrostatic repulsion of organic matter molecule from polar groups on carbon surface and adsorbed water molecules. The basic parameters of adsorption were calculated by the Dubinin–Radushkevich equation. We determined that for AG-OV-1 and SKD-515 in the coordinates of the Dubinin–Radushkevich equation, there are two linear plots suggesting adsorption in pores of different sizes or reorientation of adsorbate molecules on the activated carbon surface. The efficiency of TCE removal by the activated carbons was evaluated. To reduce the TCE to the maximum allowable, the lowest sorbent consumption was observed for AC with the highest values of surface area and micropore volume. However, the high cost and hydrophobicity of these adsorbents make it impractical to use them in adsorption columns with a fixed layer. We offered an adsorbent that reasonably combines extraction efficiency, ease of operation and economic feasibility.

Arylcyanoacetylenes trigger the assembly of dihydropyrimido[1,2-a]quinolin-3-ones in good to excellent yields on the platform of quinolines in the presence of KOH in aqueous media at room temperature. This green on-water methodology provides a simple one-pot access to a novel family of the pharmaceutically prospective compounds.

A new mechanism of the dipole-induced dipole polarizability effect by the example of 1-halogensilatranes is proposed. The mechanism involves a through-space interaction between the dipole moment μ of the core and the dipole Δμ which is induced on the halogen and, in turn, induces an extra dipole ΔΔμ on the transannular bond Si ← N to make it stronger. This effect explains for the first time the previously discovered contradiction for 1-halogensilatranes where an inverse dependence in the linear correlations between the Si ← N bond length, δ15N, δ1H(CH2N) chemical shifts, and the inductive constant σ are observed. For example, the length of the Si ← N coordination bond is shorter in 1-chlorosilatranе than in 1-fluorosilatrane due to the fact that the polarizability effect is stronger than the inductive effect in the case of the Cl atom.

Currently, the chemistry of organofluorine compounds is a leading and rapidly developing area of organic chemistry. Fluorine present in a molecule largely determines its specific chemical and biological properties. This thematic issue covers the trends of organofluorine chemistry that have been actively developed in Russia the last 15 – 20 years. The review describes nucleophilic substitution and heterocyclization reactions involving fluorinated arenes and quinones and skeletal cationoid rearrangements in the polyfluoroarene series. The transformations involving CF3-substituted carbocations and radical cations are considered. Heterocyclization and oxidative addition reactions of trifluoroacetamide derivatives and transformations of the organic moiety in polyfluorinated organoboranes and borates with retention of the carbon – boron bond are discussed. Particular attention is devoted to catalytic olefination using freons as an efficient synthetic route to fluorinated compounds. The application of unsymmetrical fluorine-containing N-heterocyclic carbene ligands as catalysts for olefin metathesis is demonstrated. A variety of classes of organofluorine compounds are considered, in particular, polyfluorinated arenes and 1,2-diaminobenzenes, 1-halo-2-trifluoroacetylacetylenes, α-fluoronitro compounds, fluorinated heterocycles, 2-hydrazinylidene-1,3-dicarbonyl derivatives, imines and silanes. The potential practical applications of organofluorine compounds in fundamental organic chemistry, materials science and biomedicine are outlined. The bibliography includes 1019 references.

DFT and MP2 computations have been performed on the fluorosilanes bearing 8-mercaptoquinoline moiety C 9 H 6 NSCH 2 SiF n Me 3−n (n = 1–3). The IR spectroscopy data show the existence of intramolecular N → Si interaction in C 9 H 6 NSCH 2 SiF 3 . Intramolecular N → Si interaction stimulates the formation of intramolecular F⋯H hydrogen bond. Bader's Quantum Theory of Atoms-in-Molecules (QTAIM) is used to investigate physical nature of these bonds. The influence of the replacement of equatorial fluorine atoms by a methyl group in the SiF 3 fragment (retaining the N → Si –F ax fragment) on intramolecular interactions was studied.

A convenient method for the synthesis of high-boiling-point α-(trifluoromethyl)styrenes was proposed. The regioselective synthesis of a series of ethyl 5-aryl-5-(trifluoromethyl)-4,5- dihydroisoxazole-3-carboxylates was conducted by the reaction of ethyl nitroacetate with α-(trifluoromethyl)styrenes in the presence of 1,4-diazabicyclo[2.2.2]octane as a catalyst. The effect of the resulting compounds on seed germination and root formation was studied.

A highly efficient stereoselective synthesis of CF3-oxazinoquinolines was elaborated using the reaction of CF3-ynones with quinolines in water. It was demonstrated that under these green conditions, the reaction proceeds up to 20 times faster to provide target compounds in almost quantitative yields. Moreover, this method is devoid of any chromatographic purification to give CF3-oxazinoquinolines with complete diastereoselectivity. The presented eco-friendly approach was found much more efficient than standard reactions in organic solvents. The synthetic utility of the prepared CF3-oxazinoquinolines was demonstrated.

3-Arylpropynenitriles are readily annulated with phenanthridine in the KOH/H2O/MeCN system at room temperature to afford 4-aryl-1,13b dihydropyrimido[1,2-f]phenanthridin-2-ones. The moderate yield of the products can be rationalized by the anionic oligomerization of an intermediate zwitterion adduct of the reactants. The reaction represents a single-stage access to a new family of pharmaceutically prospective compounds.

Background: Hypoxia renders tumor cells refractory to treatment. One way to overcome this problem is the design of drug delivery systems that contain the antitumor agent within an oxygen supply medium. Objective: to evaluate whether the perfluorocarbon liquids (capable of retaining up to 50% v/v amounts of O2 gas) can be tools for delivery of photosensitizers to hypoxic tumors. Method: We synthesized a series of compounds in which fluoroaliphatic or fluoroaromatic moieties were conjugated to the porphyrin ring in meso-positions. Two derivatives were tested as the solutions prepared either from a dimethylformamide stock (‘free’ formulation) or from a perfluorocarbon emulsion in which the photosensitizer is entrapped in the oxygenated medium. Results: In the emulsion the hydrophobic photosensitizer and the gas transporting liquid represented a biocompatible composition. Free formulations or perfluorocarbon emulsions of fluorinated porphyrins evoked little-to-null dark cytotoxicity. In contrast, each formulation triggered cell death upon light activation. Photodamage in the presence of fluorinated porphyrins was achievable not only at normoxic (20.9% O2 v/v) conditions but also in hypoxia (0.5% O2). With new compounds dissolved in the medium the cell photodamage in hypoxia was negligible whereas a significant photodamage was achieved with the emulsions of fluorinated porphyrins. The derivative with the fluoroalkyl substituent was more potent than its structurally close analog carrying the fluoroaryl moiety. Conclusion: Our new fluorinated porphyrin derivatives, especially their emulsions in which the photosensitizer and the oxygenated medium are coupled into one phase, can be perspective for photoelimination of hypoxic tumor cells.

Metal- and solvent-free reaction of quinolines with two molecules of aryltrifluoroacetylacetylenes afforded 3-arylethynyl-3-trifluoromethyl-1,3-oxazinoquinolines in up to 92% yields. The formation of a zwitterionic intermediate in the first step triggered a multistep domino reaction. This one-pot synthesis opens an easy access to novel quinoline derivatives bearing trifluoromethyl, acetylene and ketone functions, thus providing a powerful tool for drug design.

Metal-free reaction between quinolines, aryltrifluoroacetylacetylenes and water at -18 °C-rt in MeCN resulted in stereoselective assembly of trifluoromethylated oxazinoquinolines with up to 99% yield that was essentially in contrast to a similar reaction with pyridines. The annulation proceeded via the 1,3-dipolar adducts of quinolines with trifluoroacetylacetylenes followed by intramolecular cyclization involving the trifluoroacetyl group and a molecule of water.

The reaction of 2-methylquinoline with 3-phenylprop-2-ynenitrile in the presence of water (0—25 °C, 20 mol.% KOH, 5 equiv. H2O) is accompanied by the loss of aromaticity of the quinoline nucleus and results in double functionalization of the molecule at the nitrogen atom and the methyl group. Two 2-cyano-1-phenylethenyl groups were introduced into the molecule to form (2E,4E)-4-{1-[(Z)-2-cyano-1-phenylethenyl]quinolin-2(1H)-ylidene}-3-phenylbut-2-enenitrile in 59—67% yield. This reaction is stereoselective: the N-2-cyano-1-phenylethenyl-substituent has the Z-configuration, while the 1,3-diene moiety at the methyl group has the E,E-configuration. (2E)-3-Phenyl-4-(quinolin-2-yl)but-2-enenitrile that formed as a by-product (0—24% yields) is formally the addition product of the methyl group of the quinoline substrate at the acetylenic bond.

A new mechanism of the dipole—induced dipole polarization interaction was considered to explain an anomalous increase in the +I effect in a 1-phenylsilatrane molecule with the pentacoordinated Si atom. The interaction through the space between the silatrane cage having a high dipole moment and easily polarizable aromatic phenyl substituent induces dipole that adds the influence of the inductive effect along the bonds, which is characteristic of usual silatranes. The high inductive constant σI calculated for 1-phenylsilatrane on the basis of chemical shifts δC of aromatic carbon atoms was interpreted as a superelectronodonor effect in silatranes. However, the polarization effect through the space leads to a substantial change in the chemical shifts δC for the phenyl group in the direction that formally corresponds to the enhancement of the +I effect transmitted via the bonds. It is shown for the first time that the inductive effect in silatranes is not constant and varies according to the polarizability of the substituent at the Si atom.

The article is focused on the recently developed methodology for the efficient synthesis of diverse highly unsaturated previously unknown highly functionalized enamines, which comprises the mild transition-metal free hydrative ringopening of pyridines and imidazoles proceeding via zwitterionic adducts of these heterocycles with electron-deficient acetylenes. The synthesized compounds are of high synthetic and pharmaceutical value being promising intermediates for drug design.

4-Nitrophenyl)(2-phenylquinolin-3-yl)methanone has been synthesized in one step by simultaneous double C2/C3 functionalization of the pyridine ring of quinoline molecule by the action of p-nitrobenzoyl( phenyl)acetylene in aqueous potassium hydroxide.

2-Methylquinoline reacts with 1-(het)aryl-3-phenylprop-2-yn-1-ones under mild transition metal-free conditions (55–60 °C, 20 mol% KOH, H2O, MeCN) to afford 2-{5’-(het)aryl[1,1’ : 3’,1”]terphenyl-4’-yl}quinolines in up to 35% yield. The reaction likely proceeds via the intermediate 1,3-dipole followed by the double nucleophilic vinylation of the methyl group with two molecules of ynone and subsequent elimination of (het)arenecarboxylic acid.

The nucleophilic addition of imidazole derivatives to trifluoromethylated acetylenes was studied. Unpredictable regioselectivity of the reaction was observed to yield both β- and α-addition products. The reaction is 100% stereoselective to give the corresponding adducts as a Z -isomers only. The observed regioselectivity is discussed in terms of polarization of triple bond using experimental and calculated data.

The dependence of the apparent density of oligomethylsiloxane–filler systems on the size of the microspheres and their bulk density was established. The acid–base method was used to determine the acid–base properties of the surface of fillers and to assess the interaction at the phase boundary.

Reactions of CuCl2 with 1-(N-indolylmethyl)and 1-(N-carbazolylmethyl)silatranes (L) afforded new complexes CuCl2•L. Quantum chemical calculations of these complexes and a CuII complex with 1-(N-pyrrolylmethyl)silatrane showed that the Cu atom is coordinated to both the equatorial O atom of the silatranyl group and the π-system of the ligandś heterocycle.

The expected one-pot multiple functionalization of hydroxyquinolines and quinolones with acylacetylenes (20 mol% KOH, 5 equiv. H2O, MeCN, 55–60 °C), which, according to the previous finding, might involve the addition of OH and NH-functions to the triple bond and insertion of acylacetylenes into the quinoline scaffold, retains mainly on the formation of chalcone-quinoline ensembles in up 99% yield. The higher functionalized quinolines can be obtained in a synthetically acceptable yield, when the above ensembles are treated with the second molecule of acylacetylenes. Thus, the further insertion of second molecule of the acetylenes into the quinoline scaffold occurs as a much slower process indicating a strong adverse substituent effect of the remote chalcone moiety., Graphical abstract Image 1, Highlights • One-pot multiple functionalization of hydroxyquinolines and quinolones by acylacetylenes afforded to chalcone-quinoline ensembles. • The reaction proceeded in a short time with excellent product yields. • Broad scope of the reaction. • Deeper functionalization of primary adducts by second molecule of acylcetylene as well as by reducing the chalcone moiety to allyl alcohol.

Transition metal-free one-pot reaction of quinolines with acylarylacetylenes and water proceeds in the presence of KOH (55–60 °C, MeCN, 48 h) to afford 2-aryl-3-acylquinolines in up to 66% yield. Here, a formal replacement of the acetylene moiety by the aryl and acyl substituents in the quinoline scaffold takes place. In fact, it has been proved experimentally that the reaction involves the ring cleavage, accompanied by the rearrangement and insertion of the electron-deficient acetylene moiety to form a dihydroquinoline intermediate with an aldehyde functional group in position 4. This intermediate gives the corresponding doubly functionalized quinolines.

The metal-free regioselective C-2–H functionalization of 1-substituted imidazoles has been effected by a cascade reaction with aromatic or heteroaromatic aldehydes and acylacetylenes under mild conditions (55–60 °C, MeCN) to give (imidazol-2-yl)methyl-1,3-propanediones in 22–77 %, mainly 40–70 % yields.

Functionalized imidazoles are well known due to their pharmaceutical importance. It is not occasional that many popular medications such as metronidazole (antibiotic) [1], dacarbazine (antitumor drug) [2], cimetidine (histamine H2 receptor antagonist) [3], as well as best sold losartan and olmesartan (anti-hypertensive agents) and ondanserton (anti-vomiting drug), are imidazole derivatives [4]. Therefore, search for new methods for functionalization of imidazole ring remains one of the priority problems of modern organic synthesis. It is related to the general problem of C–H functionalization, which now attracts increasing attention of synthetic chemists [5]. In most cases such functionalization is achieved by reactions catalyzed by transition metal compounds which often have fairly complicated structure. For example, aryl substituents are introduced into the 2-position of imidazole ring via cross-coupling reactions catalyzed by palladium and copper complexes [6–9]. 1-Methylimidazole was converted into 2-{1-[diethyl(methyl)silyloxy]methyl}1-methylimidazoles in 32–92% yield in the presence of Ir4(CO)12, carbonyl compounds, and diethyl(methyl)silane [10]. However, even traces of transition metals (sometimes very toxic) in substances for pharmaceutical purposes are strongly undesirable [11]. In this communication we report the first example of noncatalytic regioselective C–H functionalization of imidazole ring with an alkoxy enone system via three-component condensation of 1-methylimidazole (1) with 1,3-diphenylprop-2-yn-1-one (2) and isobutyraldehyde (3). The product of this reaction was 3-[2-methyl-1-(1-methyl-1H-imidazol-2-yl)propoxy]1,3-diphenylprop-2-en-1-one (4) which was isolated in 69% yield as a 3 : 2 mixture of E and Z isomers (Scheme 1). The reaction was complete in 10 days at room temperature under solvent-free conditions. The progress of the reaction was monitored by IR spectroscopy, following the disappearance of the C≡C stretching band at 2198 cm. Raising the temperature to 55– 60°C shortened the reaction time to 21 h, but the yield of 4 decreased to 32%, and the isomer ratio essentially changed in favor of the E isomer (E/Z 9 : 1). It may be presumed that the Z isomer is the kinetically controlled product which is converted into more thermodynamically stable E isomer at elevated temperature. Thus, the reaction time may be shortened by more than an order of magnitude, and the E isomer can be obtained with high selectivity at the expense of the yield. The structure of 4 was proved by IR and H, C, and N NMR spectra. The H NMR spectrum of 4 ISSN 1070-4280, Russian Journal of Organic Chemistry, 2016, Vol. 52, No. 4, pp. 602–604. © Pleiades Publishing, Ltd., 2016. Original Russian Text © B.A. Trofimov, L.P. Nikitina, L.V. Andriyankova, K.V. Belyaeva, A.V. Afonin, A.G. Mal’kina, 2016, published in Zhurnal Organicheskoi Khimii, 2016, Vol. 52, No. 4, pp. 614–616.

The facile (55-60 oC) reductive functionalization of phenanthridine with acylacetylenes and water in MeCN led to the stereoselective formation of N-(Z)-acylethenyl-6-hydroxydihydrophenanthridines in 24-57% yield. This functionalization contrasts with the reactions of pyridines and quinolines with the same reagents wherein either ring opening (for pyridines) or diverse functionalizations (for quinolines) of the azine ring occurs. The functionalized dihydrophenanthridines thus obtained represent a new prospective family of precursors and building blocks for biochemistry and drug discovery.

1,3-Diphenylprop-2-yn-1-one is inserted into 3-substituted imidazo[4,5-b]pyridines upon refluxing in MeCN in the presence of equimolar amount of water to afford pyrido[2,3-b][1,4]diazocin-9-ones in up to 61% yield.