Divergent Synthesis of Chalcogenylated Quinolin-2-ones and Spiro[4,5]trienones via Intramolecular Cyclization of N-Aryl­propynamides Mediated by Diselenides/Disulfides and PhICl2

The reaction of N-arylpropynamides with (dichloroiodo)benzene (PhICl2) and diselenides/disulfides resulted in a divergent synthesis of chalcogenylated quinolinones and spiro[4.5]trienes through intramolecular electrophilic cyclization and chalcogenylation. The chalcogenyl functional group was introduced by an electrophilic reactive organosulfenyl chloride or selenenyl chloride species, generated in situ from the reaction of disulfides/diselenides and PhICl2. Notably, the divergent cyclization pathways were determined by the substituent type on the aniline ring in N-arylpropynamide substrates. Substrates bearing a fluoro, methoxy or trifluoromethoxy group at the para-position of the aniline underwent an alternative spiralization pathway to give the 3-chalcogenylated spiro[4,5]trienones.

Synthesis of 4-Substituted-1,2-Dihydroquinolines by Means of Gold-Catalyzed Intramolecular Hydroarylation Reaction of N-Ethoxycarbonyl-N-Propargylanilines

An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-N-propargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-meta-substituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning.

The assessment of the environmental hazard of isomers of 1,2,4-triazole phenolic derivatives for natural ecosystems

Its necessary to synthesize homologues of compounds frequently used in practice and to analyze their biological activity in laboratory experiments using screening tests that provide an integral assessment of biological responses to assess the effect of anthropogenic xenobiotics with different structures on ecosystems adjacent to agricultural complexes. We analyzed alcohol solutions of 2-(1H-1,2,4-triazolyl-methyl)phenol (ortho-isomer) and 4-(1H-1,2,4-triazolyl-methyl)phenol (para-isomer) in three concentrations: 0,0001; 0,001; 0.01 mg/ml using the Allium-test. The solvent was 0,1% isopropyl alcohol; the test object was Allium fistulosum L. The duration of the experiment was 5 days. Triazolide solutions significantly inhibited seed germination at all investigated concentrations. However, no significant differences were found between the isomers and the studied concentrations. Both isomers inhibited root growth at all concentrations tested. The toxicity of a triazolide containing an OH group in the para-position didnt change over the selected concentration range. For its ortho-isomer, toxicity increased with increasing concentration, reaching the toxicity of its homologue at a dose of 0,01 mg/ml. Both tested compounds significantly inhibited the proliferation of meristem cells as compared to the control. At the same time, no differences were observed in the effect of homologues with the OH-group in the para- and ortho-position on the value of the mitotic index. However, we found a paradoxical reaction: both homologues showed maximum cytotoxicity at a minimum concentration of 0,0001 mg/ml, and cytotoxicity decreased with increasing concentration compared to control. A triazolid containing an OH group in the para-position caused a block at the metaphase and anaphase stages at the lowest concentration. The specificity of its action disappeared with an increase in concentration, which was expressed in a general prophase and metaphase block. Its ortho-isomer inhibited cell division at all concentrations at the prophase stage. Both compounds are mutagenic. The number of chromosomal aberrations depended on both the structure of the compounds and their concentration. The para-homologue is less mutagenic than ortho. In the ortho-homologue, mutagenicity decreased slightly with increasing concentration. The highest mutagenicity was found for the ortho-homologue at its lowest concentration. The paper discusses possible mechanisms of action of isomers and their negative impact on plant organisms in ecosystems.

Electron attachment to microhydrated 4-nitro- and 4-bromo-thiophenol

We investigate the effect of microhydration on electron attachment to thiophenols with halogen (Br) and nitro (NO2) functional groups in the para position. We focus on the formation of anions...

Synthesis, characterization and third order nonlinear optical properties of trans-A2B-tpye cobalt corroles

A series of trans-A2B cobalt corroles, represented as [Cor(p-RPh)2(p-NO2Ph)]Co(PPh3) (1-5), where Cor is trianion of corrole, R is a CN, F, CH3, C(CH3)3 or PhCH2O on the para-position of the...

Synthesis of Galectin Inhibitors by Regioselective 3′-O-Sulfation of Vanillin Lactosides Obtained under Phase Transfer Catalysis

Vanillin-based lactoside derivatives were synthetized using phase-transfer catalyzed reactions from per-O-acetylated lactosyl bromide. The aldehyde group of the vanillin moiety was then modified to generate a series of related analogs having variable functionalities in the para- position of the aromatic residue. The corresponding unprotected lactosides, obtained by Zemplén transesterification, were regioselectively 3′-O-sulfated using tin chemistry activation followed by treatment with sulfur trioxide-trimethylamine complex (Men3N-SO3). Additional derivatives were also prepared from the vanillin’s aldehyde using a Knoevenagel reaction to provide extended α, β-unsaturated carboxylic acid which was next reduced to the saturated counterpart.

Theoretical study of the mechanism of chromogenic chemodosimeters in the detection of sulfhydryl (SH–) and hydroxyl (OH–) anions

Sulfide (S2−) is a biologically and environmentally important anion. Exposure to the sulfide anion can cause chronic, respiratory diseases and irritations in the skin and mucous membranes. The protonated HS− or H2S forms are more toxic than the S2− itself. A derivative of the family of 2,4,6-triaryl-pyrylium cations bearing an amine in the para position of the 4-aryl group is sensitive for detecting sulfide anions in solution. Through DFT calculations, performed at level B3LYP/6-31+G(d) in gas phase, these authors present the thermodynamic stability of the interaction of chemodosimeters derived from the pyrilium and thiopirilium cation with hydroxyl (OH–) and sulfhydryl (SH–) anions.

Development of methods for monitoring organic objects using arsenated sorbents

The paper considers the use of arsenic organic compounds as selective sorbents for the separation and analysis of complex organic mixtures. Based on the chromatographic factors of polarity, it was found that the studied sorbents range is characterized by high hydroxyl selectivity of the analyzed sorbates separation, due to the arsenyl oxygen presence in the structure of their molecule, which has an unshielded electron pair. It is shown that the functional substituents in the structure of the arsenic sorbents molecule have a direct effect on the chromatographic factors of polarity, the values of which increase when the functional substituents in the the phenyl ring (para-position) are introduced into the structure of the molecule. It was found that relatively low values of the chromatographic polarity factor (x) are observed for benzene, which also increases in the para-position of the ring. Based on the five-dimensional space and projection on the plane corresponding to the chromatographic factors of polarity, arsenic sorbents with extreme characteristics that have higher chromatographic factors of polarity (y) in comparison with known analogues were identified. Based on the conducted research, it was found that arsenic sorbents show high separation selectivity of aliphatic alcohols from hydrocarbons. Thus, when developing specific methods for the analysis of complex alcohol-hydrocarbon mixtures, we propose to use arsenic compounds as selective sorbents intended for the separation and analysis of substances capable of forming intermolecular hydrogen bonds under gas-liquid chromatography. At the same time, their retention times are higher than similar characteristics of non-polar compounds. This allows you to separate the analyzed components with close retention times.