Reaction 5-(Arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with L-Proline and Aldehydes

Boiling in toluene of 5-(arylmethylidene)pyrimidine-2,4,6(1H,3H,5H)-triones with L-proline and aldehyde led to the formation of previously unknown substituted 1′-arylhexahydro-1H-spiro[pyrimidine-5,2′-pyrrolysine]-2,4,6(1H,3Н,5Н)-triones.     

Thermal Rearrangements of 3<Emphasis Type="Italic">H</Emphasis>- and 4<Emphasis Type="Italic">H</Emphasis>-Pyrazoles Prepared by Reactions of 9-Diazofluoren with Methyl Tetrolate and Methyl 3-Phenylpropiolate

9-Diazofluoren adds in Et₂O at 20°C to methyltetrolate in keeping with Auwers rule and nonregioselectively adds to methyl-3-phenylpropiolate with the formation of spirocyclic 3H-pyrazoles. The methyltetrolate adduct at boiling in toluene converts into methyl 3a-methyl-3aH-dibenzo[e,g]indazole-3-carboxylate, at 190°C in benzene, into methyl 3-methyl-2H-dibenzo[e,g]indazole-2-carboxylate, and at 160°C in methanol, into 3-methyl-2H-dibenzo[e,g]indazole. Auwers adduct of methyl 3-phenylpropiolate at boiling in benzene gives cyclopropene derivative and at boiling in methanol isomerizes into methyl 3a-phenyl-3aHdibenzo[e,g]indazole-3-carboxylate. Anti-Auwers adduct at boiling in benzene isomerizes into methyl 2-phenylpyrazolo[1,5-f]phenanthridine-3-carboxylate.     

Synthesis of Block Copolymers of Styrene with <Emphasis Type="Italic">D</Emphasis>,<Emphasis Type="Italic">L</Emphasis>-Lactide by the Sequential Controlled Cationic Polymerization and Ring-Opening Anionic Polymerization

The cationic polymerization of styrene initiated by the system 2-chloro-2-phenylpropane–TiCl₄–pyridine is studied in a mixture CH₂Cl₂–n-hexane at a temperature of –80°С. It is shown that under these conditions polymerization occurs via the living mechanism at [monomer]: [initiator] ≤ 100. The method of preparing polystyrenes with terminal primary hydroxyl groups (M_n = 4000–10000 g/mol) by the sequential controlled cationic polymerization of styrene and the in situ alkylation of 4-phenoxy-1-butanol by polystyrene macrocations is proposed. The resulting functionalized polystyrenes are used as macroinitiators of anionic-coordination ring-opening polymerization of D,L-lactide in the presence of tin bis(2-ethyl hexanoate) [Sn(Oct)₂] in toluene at 80°С. Copolymers polystyrene-block-poly(D,L-lactide) with the controlled length of the poly(D,L-lactide) block (M_n = 10000–17000 g/mol) and a relatively low molecular-weight distribution (M_w/M_n = 1.6–1.8) are synthesized. Formation of the block copolymers is confirmed by ¹Н NMR spectroscopy, gel-permeation chromatography, and atomic force microscopy.     

Synthesis and the structure of 1,2-bis(6-acetyl-2-methylbenzo[<Emphasis Type="Italic">b</Emphasis>]thiophen-3-yl)cyclopentene

New 1,2-dihetarylethene containing two 6-acetyl-2-methylbenzo[b]thiophene moieties linked by the cyclopentene bridge was synthesized. In a toluene solution, this compound exhibits photochromic properties. The X-ray diffraction study showed that the crystal structure also has properties characteristic of photochromic compounds, viz., the anti-parallel conformation of the molecule and the distance between the reaction centers equal to 3.729 Å.     

<Emphasis Type="Italic">CrMAPK3</Emphasis> regulates the expression of iron-deficiency-responsive genes in <Emphasis Type="Italic">Chlamydomonas reinhardtii</Emphasis>

Background

Under iron-deficient conditions, Chlamydomonas exhibits high affinity for iron absorption. Nevertheless, the response, transmission, and regulation of downstream gene expression in algae cells have not to be investigated. Considering that the MAPK pathway is essential for abiotic stress responses, we determined whether this pathway is involved in iron deficiency signal transduction in Chlamydomonas.

Results

Arabidopsis MAPK gene sequences were used as entry data to search for homologous genes in Chlamydomonas reinhardtii genome database to investigate the functions of mitogen-activated protein kinase (MAPK) gene family in C. reinhardtii under iron-free conditions. Results revealed 16 C. reinhardtii MAPK genes labeled CrMAPK2–CrMAPK17 with TXY conserved domains and low homology to MAPK in yeast, Arabidopsis, and humans. The expression levels of these genes were then analyzed through qRT-PCR and exposure to high salt (150 mM NaCl), low nitrogen, or iron-free conditions. The expression levels of these genes were also subjected to adverse stress conditions. The mRNA levels of CrMAPK2, CrMAPK3, CrMAPK4, CrMAPK5, CrMAPK6, CrMAPK8, CrMAPK9, and CrMAPK11 were remarkably upregulated under iron-deficient stress. The increase in CrMAPK3 expression was 43-fold greater than that in the control. An RNA interference vector was constructed and transformed into C. reinhardtii 2A38, an algal strain with an exogenous FOX1:ARS chimeric gene, to silence CrMAPK3. After this gene was silenced, the mRNA levels and ARS activities of FOX1:ARS chimeric gene and endogenous CrFOX1 were decreased. The mRNA levels of iron-responsive genes, such as CrNRAMP2, CrATX1, CrFTR1, and CrFEA1, were also remarkably reduced.

Conclusion

CrMAPK3 regulates the expression of iron-deficiency-responsive genes in C. reinhardtii.

     

Cycloaminomethylation of dihydric phenols catalyzed by <Emphasis Type="Italic">d</Emphasis>- and <Emphasis Type="Italic">f</Emphasis>-metal compounds

An efficient method has been developed for the synthesis of 7,16,25-triaryl-7,8,16,17,25,26-hexahydro-6H,15H,24H-tribenzo[f,m,t][1,5,8,12,15,19,3,10,17]hexaoxatriazacyclohenicosines, 3,8-diaryl-2,3,4,7,8,9-hexahydrobenzo[1,2-e:4,3-e′]bis[1,3]oxazines, 3,9-bis(chlorophenyl)-3,4,9,10-tetrahydro-2H,8H-benzo[1,2-e:3,4-e′]bis[1,3]oxazines, and 2,9-bis(chlorophenyl)-1,2,3,8,9,10-hexahydrobenzo[1,2-e:6,5-e′]bis-[1,3]oxazines via cycloaminomethylation of pyrocatechol, resorcinol, and hydroquinone with N,N-bis(methoxymethyl) anilines in the presence of samarium catalysts.     

Alkylation of 2-(methylsulfanyl)-6-polyfluoroalkylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-ones with haloalkanes

The alkylation of ambident anions of 2-(methylsulfanyl)-6-(polyfluoroalkyl)pyrimidin-4(3H)-ones with 4-bromobutyl acetate leads to concurrent formation of O- and N-(4-acetoxybutyl) derivatives. Polar aprotic solvents favor formation of the O-isomer, and weakly polar dioxane favors N-alkylation. The reaction of 2-(methylsulfanyl)-6-(trifluoromethyl)pyrimidin-4(3H)-one with an equimolar amount of 1,2-dibromoethane in polar acetonitrile gives a mixture of N,N-, O,O-, and N,O-bridged bis-pyrimidines, as well as N- and O-[2-(methylsulfanyl)ethyl] derivatives, whereas in the presence of 10 equiv of 1,2-dibromoethane the N,O-isomer is formed as the only product. The reaction in weakly polar tetrahydrofuran yields N,N- and N,O-bispyrimidines.     

Crystalline inclusion complexes of diterpenoid isosteviol with aromatic compounds

Crystalline inclusion complexes of diterpenoid isosteviol (ent-16-ketobeyeran-19-oic acid) with individual benzene, o-, m-, p-xylenes, ethylbenzene, isopropylbenzene, o-and m-nitoranilins, benzaldehyde, styrene and naphthalene are obtained and characterized by single crystal X-ray diffraction. As determined by GC and ¹H NMR spectroscopy, isosteviol selectively includes toluene from the equimolar benzene-toluene mixture, o-xylene from a commercial mixture of xylenes, o-and m-nitroanilins from their mixture with p-nitroanilin, and also styrene from styrene-ethylbenzene and styrene-isopropylbenzene mixtures thus yielding crystalline inclusion complexes.     

Preparation of stereochemically pure <Emphasis Type="Italic">E</Emphasis>- and <Emphasis Type="Italic">Z</Emphasis>-alkenoic acids and their methyl esters from bicyclo[<Emphasis Type="Italic">n</Emphasis>.1.0]alkan-1-ols. Application in the synthesis of insect pheromones

Oxidative cleavage of exo- and endo-alkyl- and hydroxyalkyl-substituted bicyclo[n.1.0]alkan-1-ols with (diacetoxy-λ³-iodanyl)benzene gave the corresponding methyl alkenoates exclusively with E or Z configuration of the double bond. This reaction was used as the key stage in the syntheses of stereoisomerically pure components of pest insect pheromones: (E)-dodec-9-en-1-yl acetate (European pine shoot moth Rhyacionia buoliana), (Z)-tetradec-11-en-1-yl acetate (European oak leafroller Tortrix viridana), and (3E,8Z,11Z)-tetradeca-3,8,11-trien-1-yl acetate (tomato leafminer Tuta absoluta).     

Limiting activity coefficients of hydrocarbons in phenol

Temperature dependence of the limiting activity coefficients of saturated (n-hexane, n-heptane, n-octane, and cyclohexane) and aromatic (benzene, toluene, ethylbenzene, o-xylene) hydrocarbons in phenol was studied in the temperature range 308–348 K by the headspace analysis method.     

Synthesis of oxo derivatives of <Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">p</Emphasis>-tolysulfonyl)hexahydrocycloalka[<Emphasis Type="Italic">b</Emphasis>]indoles

Hydroxymercuration-demercuration of N-p-tolysulfonyl-4,4a,9,9a-tetrahydro-3H-carbazoles and N-p-tolyl(or methyl)sulfonyl-1,3a,4,8b-tetrahydrocyclopenta[b]indoles leads to the formation of the corresponding N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-2-ols and N-p-tolyl(or methyl)sulfonyl-1,2,3,3a,4,8b-hexahydrocyclopenta[b]indol-2-ols. The latter are oxidized to 2-oxo derivatives with potassium dichromate. The oxidation of 2-methoxy-8-methyl-N-p-tolylsulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-ol under analogous conditions gives 2-methoxy-8-methyl-N-p-tolysulfonyl-2,3,4,4a,9,9a-hexahydro-1H-carbazol-1-one.     

Three-component heterocyclization of 5-(arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with aldehydes and amino acids

Previously unknown substituted 4-aryl-2,7,9-triazaspiro[4.5]decane-6,8,10-triones were synthesized in 50–70% yield by heating 5-(arylmethylidene)barbituric acids with N-methyl- or N-phenylglycine and para-formaldehyde or 4-methoxybenzaldehyde in boiling toluene for 14 h.     

Influence of mixed common solvent on the co-assembled morphology of PS-<Emphasis Type="Italic">b</Emphasis>-PEO and CdS quantum dots

The hybrid structures of polystyrene-b-poly(ethylene oxide) (PS-b-PEO) block copolymer and inorganic nanoparticles with good stability and biocompatibility have potential applications in drug delivery and bioimaging. Spherical co-assemblies of PS₁₂₀-b-PEO₃₁₈ and oleylamine-capped CdS quantum dots (QDs) are produced successfully in this work by adding water to a mixed common solvent, such as N,N-dimethylmethanamide (DMF)/chloroform, DMF/tetrahydrofuran (THF), or DMF/toluene. The energy dispersive X-ray (EDX) spectrum indicates that QDs are located at the interface between the core and shell of the spherical co-assemblies. The co-assembly process during water addition is traced by transmission electron microscopy (TEM) and turbidity measurement. Spherical co-assemblies are formed through budding from bilayers of the block copolymer and QDs. The morphology of the co-assemblies is related to the miscibility of the QD-dispersing solvents with water and the morphology changes from a spherical to a vesicle-like structure with DMF/toluene. Increasing THF content in the mixed solvent causes morphological transitions from spherical co-assemblies to multi-branched cylinders and micelles where QDs are located in the central core. Increasing chloroform content yields vesicle-like structures with protruding rods on the surface. The mechanism of the morphological transitions is also discussed in detail.     

Stereochemistry of dihydroxylation of <Emphasis Type="Italic">N</Emphasis>-arylbicyclo[2.2.1]-hept-5-ene-<Emphasis Type="Italic">endo</Emphasis>- and -<Emphasis Type="Italic">exo</Emphasis>-2,3-dicarboximides

Stereochemistry of the oxidation of N-arylbicyclo[2.2.1]hept-5-ene-endo-and-exo-2,3-dicarboximides at the double bond with peroxyacetic acid generated in situ in the presence of sulfuric acid and with an anhydrous dioxane solution of peroxyacetic acid was studied. In both cases, the reaction was stereospecific, regardless of the substituent in the N-aryl group and configuration of the imide ring, but the reaction direction depended on the presence of water in the system. In the first case, the corresponding trans-5,6-dihydroxy derivatives were formed, while in the second, exo-5,6-epoxy derivatives. The oxidation of N-arylbicyclo[2.2.1]-hept-5-ene-endo-and-exo-2,3-dicarboximides with a solution of potassium permanganate in aqueous acetone gave the corresponding N-aryl-cis-5,6-dihydroxybicyclo[2.2.1]heptane-endo-and-exo-2,3-dicarboximides. The exo,cis,exo and exo,cis,endo configurations of the synthesized compounds were determined by ¹H NMR spectroscopy.     

Synthesis and structure of bis(1,2-diaminoethane) copper(II) bis(<Emphasis Type="Italic">o</Emphasis>-hydroxybenzoate) monohydrate and <Emphasis Type="Italic">trans</Emphasis>-diaquabis(1,2-diaminoethane)copper(II) bis(<Emphasis Type="Italic">o</Emphasis>-aminobenzoate)

X-ray structural analysis has been performed for two complex compounds: Cu(en)₂(o-HB)₂H₂O (I) (a = 16.873(4) Å, b = 8.713(2) Å, c = 14.803(3) Å, β = 91.15(2)°, V = 2175.8(8) ų, C2/c, Z = 4, R(F) = 0.0263, 1516 reflections with I > 3σ (I)) and [Cu(en)₂(OH₂)₂]²⁺(o-AB^?)₂ (II) (a = 7.488(5) Å, b = 22.122(8) Å, c = 7.856(5) Å, β = 118.77(2)°, V = 1140.7(11) ų, P2₁/n, Z = 2, R(F) = 0.0432, 1684 reflections with I > 3σ(I)) synthesized under identical conditions (en is ethylenediamine, o-HB is o-hydroxybenzoate, and o-AB is o-aminobenzoate). Although the compounds were assumed to have similar structures and the Cu-Lig bond lengths and the cis and trans angles are acceptable for an octahedral structure, the geometric parameters of o-HB suggest that the copper atom has a plane square environment.     

Peculiarities of the reaction of alkali metal bis(trimethylsilyl)amides with halobenzenes

Lithium and sodium bis(trimethylsilyl)amides react with fluoro-, bromo-, and chlorobenzenes in THF or toluene to give a mixture of N,N-bis(trimethylsilyl)aniline and N,2-bis(trimethylsilyl)aniline. The latter compound is resulted from 1,3-shift of the trimethylsilyl group from nitrogen to ortho-carbon atom of the benzene ring. Effects of the solvent, halogen, and alkali metal nature as well as the reaction conditions on the ratio of isomers were examined. Reaction of iodobenzene with sodium bis(trimethylsilyl)amide in THF produces N,N-bis(trimethylsilyl)aniline and 2-iodo-N,N-bis(trimethylsilyl)aniline, while in toluene a mixture of three products, two indicated above and N,N-bis(trimethylsilyl)benzylamine, was obtained.     

1,3-Dipolar cycloaddition of 3-phenylamino-5-phenylimino-1,2,4-dithiazole to 1-acyl-2-phenylacetylenes—A new route to functionalized 1,3-thiazole derivatives

3-Phenylamino-5-phenylimino-1,2,4-dithiazole reacted with 1-acyl-2-phenylacetylenes in ethanol or toluene on heating (78–80°C, 1 h) in chemo- and regioselective fashion to give previously unknown N-[5-acyl-3,4-diphenyl-1,3-thiazol-2(3H)-ylidene]-N′-phenylthioureas (yield 57–60%). The structure of N-[5-benzoyl-3,4-diphenyl-1,3-thiazol-2(3H)-ylidene]-N′-phenylthiourea was proved by X-ray analysis.     

Graphene oxide promoted synthesis of <Emphasis Type="Italic">p</Emphasis>-phenylenediamine antioxidants

Three p-phenylenediamine antioxidants (p-phenylenediamine-N,N,N′,N′-tetrapropionic acid tetramethyl ester, p-phenylenediamine-N,N,N′-tripropionic acid trimethyl ester, and p-phenylenediamine-N, N′-dipropionic acid dimethyl ester) were successfully synthesized via atom-economic aza-Michael addition of pphenylenediamine to methyl acrylate p-romoted by graphene oxide in water. The synthesized compounds were characterized by NMR, ESI-MS spectra, and elemental analyses. The effects of the solvent and graphene oxide on the reaction were investigated.     

Crystal structures of a family of layered coordination polymers containing divalent metal ions (Mn<Superscript>2+</Superscript>, Co<Superscript>2+</Superscript>, Ni<Superscript>2+</Superscript> and Zn<Superscript>2+</Superscript>) and the 3-amino 4-methyl benzoate ion

The syntheses and crystal structures of the layered coordination polymers M(C₈H₈NO₂)₂ [M = Mn (1), Co (2), Ni (3) and Zn (4)] are described. These isostructural compounds contain centrosymmetric trans-MN₂O₄ octahedra as parts of infinite sheets; the ligand bonds to three adjacent metal ions in μ³-N,O,O′ mode from both its carboxylate O atoms and its amine N atom. In each case, weak intra-sheet N–H?O and C–H?O hydrogen bonds may help to consolidate the structure. Crystal data: 1, C₁₆H₁₆MnN₂O₄, M _r = 355.25, monoclinic, P2₁/c (No. 14), a = 10.6534(2) Å, b = 4.3990(1) Å, c = 15.5733(5) Å, β = 95.1827(10)°, V = 726.85(3) ų, Z = 2, R(F) = 0.026, wR(F ²) = 0.067. 2, C₁₆H₁₆CoN₂O₄, M _r = 359.24, monoclinic, P2₁/c (No. 14), a = 10.6131(10) Å, b = 4.3374(4) Å, c = 15.3556(17) Å, β = 95.473(4)°, V = 703.65(12) ų, Z = 2, R(F) = 0.041, wR(F ²) = 0.091. 3, C₁₆H₁₆N₂NiO₄, M _r = 359.02, monoclinic, P2₁/c (No. 14), a = 10.6374(4) Å, b = 4.2964(2) Å, c = 15.2827(8) Å, β = 95.9744(14)°, V = 694.66(6) ų, Z = 2, R(F) = 0.028, wR(F ²) = 0.070. 4, C₁₆H₁₆N₂O₄Zn, M _r = 365.68, monoclinic, P2₁/c (No. 14), a = 10.6385(5) Å, b = 4.2967(3) Å, c = 15.2844(8) Å, β = 95.941(3)°, V = 694.89(7) ų, Z = 2, R(F) = 0.038, wR(F ²) = 0.107.     

Cyclization of trifluoro-<Emphasis Type="Italic">N</Emphasis>-(prop-2-yn-1-yl)methanesulfonamides to <Emphasis Type="Italic">N</Emphasis>-(hydroxymethyl)-1,2,3-triazoles

Three-component heterocyclizations of trifluoro-N-(prop-2-yn-1-yl)methanesulfonamide, trifluoro-N-pheny-N-(prop-2-yn-1-yl)methanesulfonamide, and trifluoro-N,N-di(prop-2-yn-1-yl)methanesulfonamide with formaldehyde and sodium azide afforded N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-, N-{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}-N-phenyl-, and N,N-bis{[2-(hydroxymethyl)-2H-1,2,3-triazol-4-yl]methyl}trifluoromethanesulfonamides as the major products together with minor 1-(hydroxymethyl)-1H-1,2,3-triazole isomers.