Directed Aminomethylation of Pyrrole,Indole, and Carbazole with <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>,<Emphasis Type="Italic">N′</Emphasis>-Tetramethylmethanediamine

Catalytic aminomethylation of pyrrole and indole with N,N,N′,N′-tetramethylmethanediamine in the presence of 5 mol % of ZrOCl₂·8H₂O proceeds selectively at the positions 2, 5 of pyrrole and 1, 3 of indole. Carbazole under the same conditions affords 3-formyl-9-aminomethyl derivative. The reaction in the presence of 5 mol % of K₂CO₃ occurs as monoaminomethylation: for pyrrole at the position 2, for indole at the position 3, and for carbazole at the nitrogen atom of the substrate. Water-soluble 1,1′-(1H-pyrrole-2,5-diyl)bis(N,N-dimethylmethanamine) exhibits a fungistatic activity with respect to phytopathogenic fungi Rhizoctonia solani.     

1,3-Diamino-2-Hydroxypropane-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-Tetraacetic Acid: Crystal and Molecular Structures

The synthesis, IR spectroscopic study, and X-ray diffraction analysis (CIF file CCDC no. 1574078) are carried out for 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (I). The structural units of a crystal of compound I are (H_4.5HPdta)^0.5– anions, (H_5.5HPdta)^0.5+ cations, and molecules of water of crystallization joined by a branched network of hydrogen bonds: strong intermolecular O–H…O and intramolecular N–H…O bonds.     

Pseudo-Polymorphs of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis(4-nitrophenyl)-2,6-Pyridinedicarboxamide

Three pseudo-polymorphs of N, N′-bis(4-nitrophenyl)-2,6-pyridinedicarboxamide 1 were characterized by X-ray crystallography. The C–H ⋅s O hydrogen bond was found to contribute significantly to the assembly of this host. With the variation of the guest, the host changed the molecular conformation and the supramolecular synthons. In all three cases concerned, the solvent guests were bonded through direct host-guest interaction and accommodated in the voids formed by the assembly of the host.     

Complex formation of magnesium and calcium ions with trimethylenediamine-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>’,<Emphasis Type="Italic">N</Emphasis>’-tetraacetic acid

Stability constants and heat effects of the formation reactions of magnesium and calcium trimethylenediaminetetraacetates at 298.15 K and ionic strength of 0.1, 0.5, and 1.0 (mol/L KNO₃) have been determined by means of potentiometry and calorimetry. Standard thermodynamic parameters (log K⁰, Δ_rG⁰, Δ_rH⁰, and Δ_rS⁰) of the studied equilibriums have been determined.     

<Emphasis Type="Italic">β</Emphasis>-Chloro-<Emphasis Type="Italic">α</Emphasis>,<Emphasis Type="Italic">β</Emphasis>-unsaturated carbonyls as convenient precursors of highly substituted benzenes

The Diels–Alder reactions of three β-chloro-α,β-unsaturated carbonyl compounds 1–3 with different dienes were carried out to afford highly functionalized cyclohexenes 4–9, bearing quaternary centers, in good yields. These cycloadducts (CAs) undergo dehydrochlorination with subsequent aromatization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene DBU to produce new substituted benzenes 11–14. Compound 10 is the product of lactonization and removal of an HCl molecule from compound 7. All products were characterized by NMR, IR, elementary analysis and some of them by MS. Structure assignments of isomers were carried out on the basis of NMR chemical shifts and coupling constants using 1D, 2D and heteronOe NMR techniques.     

Thermophysical properties of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimеthylacetamide mixtures with <Emphasis Type="Italic">n</Emphasis>-butanol

The refraction, dielectric, viscosity, density, data of the binary mixtures of N,N-dimethylacetamide (DMA) with n-butanol at 308.15 and 313.15 K. The measured parameters used to obtain derived properties like Bruggeman factor, molar refraction and excess static dielectric constant, excess inverse relaxation time, excess molar volume and excess viscosity, excess molar refraction. The variation in magnitude with composition and temperature of these quantities has been used to discuss the type, strength and nature of binary interactions. Results confirm that there are strong hydrogen-bond interactions between unlike molecules of DMA+ n-butanol mixtures and that 1: 1 complexes are formed and strength of intermolecular interaction increases with temperature.     

A Lemieux–Johnson oxidation of shikimic acid derivatives: facile entry to small library of protected (2<Emphasis Type="Italic">S</Emphasis>,3<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">R</Emphasis>)-2,3,4,7-tetrahydroxy-6-oxoheptanals

The Lemieux–Johnson oxidation was employed for the cleavage of the carbon–carbon double bond of shikimic acid derivatives. Through this procedure, a series of the sixteen novel (2S,3S,4R)-2,3,4,7-tetrahydroxy-6-oxoheptanals bearing three contiguous stereocentres have been synthesized in excellent yields.     

Spectroscopic and electrical characterization of <Emphasis Type="Italic">α</Emphasis>,<Emphasis Type="Italic">γ</Emphasis>-bisdiphenylene-<Emphasis Type="Italic">β</Emphasis>-phenylallyl radical as an organic semiconductor

The semiconductor properties of the earliest known stable radical, α,γ-bisdiphenylene-β-phenylallyl radical (Koelsch radical, 1^?) were assessed using spectroscopic and electrical techniques. This radical undergoes reversible redox processes, and it has low redox potentials. In addition, 1^? possesses long wavelength absorption bands, owing to the existence of a singly-occupied molecular orbital whose energy level lies between those of the HOMO and LUMO. A spin-coated thin-film of 1^? displays photocurrent and an electron mobility of 6.3 × 10^?7 cm² V^?1 s^?1 on a trially-fabricated organic field effect transistor.     

<Emphasis Type="Italic">N</Emphasis>′-tetrazolylmethoxyl derivatives of <Emphasis Type="Italic">N</Emphasis>-methyldiazene <Emphasis Type="Italic">N</Emphasis>-oxides

A preparation method was developed for previously unknown tetrazole derivatives containing in the 1, 2, and/or 5 positions of the tetrazole ring N-methyldiazene-N-oxide-N′-oxymethyl groups.     

Allylic oxidation of 19<Emphasis Type="Italic">β</Emphasis>,28-epoxy-a-neo-5<Emphasis Type="Italic">β</Emphasis>-methyl-25-nor-18<Emphasis Type="Italic">α</Emphasis>-olean-9-ene

Allylic oxidation of 19β,28-epoxy-A-neo-5β-methyl-25-nor-18α-olean-9-ene by ozone produced 19β,28-epoxy-A-neo-5β-methyl-25-nor-18α-olean-9-en-1-one.     

Converting dipyrrinones to lactim ethers to fluorescent <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-difluoroboryl derivatives

A high-yield straightforward conversion of lactams to lactim ethers is shown by the conversion of (10H)-dipyrrin-1-ones to (11H)-dipyrrin-1-ol methyl and ethyl ethers in 90% yield from heating in neat trimethyl or triethyl phosphite at 160°C. Unlike the parent dipyrrinones, which form intermolecularly hydrogen-bonded dimers in CHCl₃, their lactim ethers are shown to be monomeric by vapor pressure osmometry. The latter react with boron trifluoride etherate to N,N′-bridged BF₂ derivatives that exhibit strong fluorescence (φ_F 0.6–0.8) near 535 nm. X-Ray crystal structures were obtained of the lactim ethyl ether of kryptopyrromethenone and the BF₂ derivative of the lactim ethyl ether 2,3-diethyl-7,8-dimethyl-(10H)-dipyrrin-1-one. Correspondence: David A. Lightner, Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020 USA.     

Oxidation of reaction products of <Emphasis Type="Italic">p</Emphasis>-aryl-<Emphasis Type="Italic">С</Emphasis>,<Emphasis Type="Italic">С</Emphasis>-disubstituted nitrones and dimethyl 3-methylenecyclopropane-1,2-dicarboxylate

Oxidation with 2,3-dichloro-4,5-dicyanobenzoquinone of 2,4-dihydro-1Н-azeto[1,2-a]quinoline-3,4 -dicarboxylates obtained in the reaction of N-aryl-С,С-disubstituted nitrones with Feist’s acid ester resulted in the formation of 2-vinylquinoline-3,4-dicarboxylates in good yields.     

Synthesis and electrochemical Reduction of 2,2′-diaryl-5,5,5′,5′-tetramethyl-3,3′-bi(pyrrol-3-ylidene)-4,4′(5<Emphasis Type="Italic">H</Emphasis>,5′<Emphasis Type="Italic">H</Emphasis>)-dione 1,1′-dioxides

2,2′-Diaryl-5,5,5′,5′-tetramethyl-3,3′-bi(pyrrol-3-ylidene)-4,4′(5H,5′H)-dione 1,1′-dioxides containing a carboxy, alkoxycarbonyl, or carbamoyl group in the para position of one or both benzene rings were synthesized. These compounds may be regarded as cyclic dinitrones with conjugated C=C bond. Mild aminolysis of carboxy groups in the title compounds may be used to introduce dinitrone fragments into oligonucleotide or polypeptide structures. Electrochemical reduction of the resulting amides involves reversible oneelectron transfer in the first step at a near-zero potential, which makes it possible to use the title compounds as electrochemically active labels in applied bioorganic electrochemistry.     

Structural and crystal chemistry analysis of (4<Emphasis Type="Italic">E</Emphasis>)- and (4<Emphasis Type="Italic">Z</Emphasis>)-6,6′,7,7′-tetrahydro-5H,5′H-4,4′-<Emphasis Type="Italic">bis</Emphasis>-1-benzothiophenes

(4E)-6,6′,7,7′-tetrahydro-5H,5′H-4,4′-bis-1-benzothiophene and (4Z)-6,6′,7,7′-tetrahydro-5H,5′H-4,4′-bis-1-benzothiophene are studied by means of X-ray diffraction. The intermolecular interaction energy is calculated and the structural subclass of each compound is derived. These compounds have been found to have similar full crystal energies and packing efficiencies. The observed pseudosymmetry effects are described.     

Recognition of <Emphasis Type="Italic">R</Emphasis>- and <Emphasis Type="Italic">S</Emphasis>-Isomers of α-Alanine by Chiral Nanotubes

DFT PBE/3ζ study of relative stability of the R- and S-isomers of α-alanine in open carbon nanotubes with chirality indices (5,5), P,M-(5,1) and P,M-(5,2) has shown that the encapsulated molecule of the amino acid notably changes its geometrical and electronic characteristics. Besides, for the clusters α-alanine@nano (5,2) the most stable are practically degenerate in energy adducts S-alanine@P-(5,2) and R-alanine@М-(5,2). All this indicates the ability of chiral nanotubes to recognize encapsulated molecules of the R- and S-isomers.     

1,7′-dimethyl-2′-propyl-1<Emphasis Type="Italic">H</Emphasis>,3′<Emphasis Type="Italic">H</Emphasis>-2,5′-bibenzo[<Emphasis Type="Italic">d</Emphasis>]imidazole as a corrosion inhibitor of mild steel in 1 M HCl

Inhibition effect of imidazole derivative 1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole (DPBI) against mild steel corrosion in 1 M HCl solutions was evaluated using the conventional mass loss method, potentiodynamic polarization, linear polarization, and electrochemical impedance spectroscopy. The mass loss results showed that DPBI is an excellent corrosion inhibitor; electrochemical polarizations data revealed the mixed mode of inhibition; and the results of electrochemical impedance spectroscopy showed that the change in the impedance parameters, charge transfer resistance, and double layer capacitance with the change in the concentration of the inhibitor is due to the adsorption of the molecule leading to the formation of a protective layer on the surface of mild steel. The inhibition action of this compound was assumed to occur via adsorption on the steel surface through the active centers of the molecule.     

Unusual transformation of (1<Emphasis Type="Italic">R</Emphasis>,1′<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-1-(3-diisopropylamino-3-oxopropyl)-2-(1-hydroxyethyl)cyclopropane in the course of the cyclopropylcarbinyl rearrangement

The cyclopropylcarbinyl rearrangement of (1R,1′ S,2S)-1-(3-diisopropylamino-3-oxo-propyl)-2-(1-hydroxyethyl)cyclopropane and the participation of the amide moiety in the intramolecular process smoothly affords the (2′ E,5S)- N,N-diisopropyl-N-[5-(but-2′-enyl)tetra-hydrofuran-2-yridene ] ammonium salt.     

3α,14α,22<Emphasis Type="Italic">R</Emphasis>,25-Tetrahydroxy-5β(<Emphasis Type="Italic">H</Emphasis>)-cholest-7-en-6-one,a phytoecdysteroid from <Emphasis Type="Italic">Acanthophyllum gypsophiloides</Emphasis> possessing anti-inflammatory and analgesic activities

A representative of the ecdysteroid series, 3α,14α,22R,25-tetrahydroxy-5β(H)-cholest-7- en-6-one, possessing anti-inflammatory and analgesic activities, was isolated from a water—ethanol extract of the aerial part of Acanthophyllum gypsophiloides Regel after chromatographic removal of non-polar components.     

Theoretical and experimental NMR studies of the Swern oxidation of methyl 6<Emphasis Type="Italic">α</Emphasis>,7<Emphasis Type="Italic">β</Emphasis>-dihydroxyvouacapan-17<Emphasis Type="Italic">β</Emphasis>-oate

This work describes the synthesis of new derivatives of 6α,7β-dihydroxyvouacapan-17β-oic acid (1) employing the Swern method for the oxidation of C-6 and C-7 of methyl 6α,7β-di-hydroxyvouacapan-17β-oate (2) and the formation of methyl 6,7-dioxovouacapan-17β-oate (3). NMR structural studies associated with theoretical calculations of reaction intermediates and products are also reported. The mixture of methyl 7β-hydroxy-6-oxovouacapan-17β-oate (4; 21%) and methyl 6α-hydroxy-7-oxovouacapan-17β-oate (5; 79%) was the product from the first step of the oxidation of 2. The lower energy of 5, calculated by HF/6-31G* and DFT/BLYP/6-31G* methods, reinforces the thermodynamic control proposed for the reaction. After further Swern oxidation of the mixture of 4 and 5, the isomeric form methyl 6-hydroxy-7-oxovouacap-5-en-17β-oate (6) was obtained. Theoretical calculations indicate a lower energy for the mono-enol 6 than the 1,2-diketo 3 and the other mono-enol methyl 7-hydroxy-6-oxovouacap-7-en-17β-oate (7).