Synthesis and Characterization of the Poly-(2-Methoxycyanurate) of 1,1′-Bis-(4-Hydroxyphenyl)-cyclohexane

The poly-(2-methoxycyanurate) of l, l′-bis-(4-hydroxyphenyl)-cyclohexane (PMCBC) was synthesized by the interfacial poly-condensation technique. The polymer was fractionated by preparative gel permeation chromatography (GPC). The fractions were characterized by viscometry, osmometry, and GPC techniques. The viscosity-molecular weight relationship was established in pure solvent and in different binary solvent mixtures. The unperturbed dimensions, (〈R²〉₀/M)^1/2, and the solvent-polymer interaction parameter, B, were computed by applying the two-parameter theories of the excluded-volume effect.     

1-(4-Nitrophenoxycarbonyl)-7-pyridin-4-yl indolizine: a new versatile fluorescent building block. Application to the synthesis of a series of fluorescent β-cyclodextrins

The synthesis of a series of new fluorescent building blocks 1a-d incorporating a pyridinoindolizine unit and two potentially reactive sites is described. The reaction of 1a-d with the mono-6-amino-6-deoxy-β-cyclodextrin provides the corresponding fluorescent water soluble hosts 2a-d in good yield. The sensor properties of 2a-d in the presence of 1-adamantanol is described.     

Synthesis of Gingerenone C and 5-Hydroxy-1-(4′-hydroxy-3-methoxyphenyl)-7-(4′′-hydroxyphenyl)-3-heptanone

Diarylheptanoidsconstituteadistinctgroupofmetabolitesofnaturalplantcharacterizedbytwoaromaticringslinkedbyalinearsevenaliphaticchain.Therehavebeenfewreportsonthebiologicalactivitiesofdiarylheptanoids,mostofwhichappearingintheareasofanti-inflammatory,anti-oxidative,superoxidescavengingandanti-hepatotoxiceffects1,2.SomeofthemareusedastraditionalmedicineinAsia3.Compound1and2werefirstlyisolatedfromtherhizomesofZingiberofficalrespectively4,5.Sofarthesynthesisofthesetwocompoundshavenotbeenreportedy…     

Syntheses and Crystal Structures of Polynuclear Cu(I) Complexes Containing the 1,1′-Bis-(diphenylphosphino)-ferrocene Ligand

 The reaction between [Cu(NCMe)₄][PF₆] and 1,1′-bis-(diphenylphosphino)-ferrocene (dppf) in several ratios, solvents, and conditions led to the synthesis and structural characterization of the Cu(I) complexes [Cu(dppf)(Odppf)][PF₆] (1), [(dppf)Cu(μ-dppf)Cu(dppf)][PF₆]₂ (2), and [(dppf)Cu(μ-Cl)₂Cu(dppf)] (3). Although 1 and the cation in 2 were known, the first was structurally characterized for the first time, exhibiting a significant asymmetry in the coordination sphere of Cu(I) owing to the presence of oxygen. In 2, the PF₆ ⁻ anion led to an interesting crystal packing with large open channels containing water. Finally, DFT calculations on a model of 3 showed that its HOMO exhibits, besides Fe, a significant Cu and Cl character, which is reflected in its electrochemical properties.     

Syntheses and Crystal Structures of Polynuclear Cu(I) Complexes Containing the 1,1′-Bis-(diphenylphosphino)-ferrocene Ligand

Summary.  The reaction between [Cu(NCMe)₄][PF₆] and 1,1′-bis-(diphenylphosphino)-ferrocene (dppf) in several ratios, solvents, and conditions led to the synthesis and structural characterization of the Cu(I) complexes [Cu(dppf)(Odppf)][PF₆] (1), [(dppf)Cu(μ-dppf)Cu(dppf)][PF₆]₂ (2), and [(dppf)Cu(μ-Cl)₂Cu(dppf)] (3). Although 1 and the cation in 2 were known, the first was structurally characterized for the first time, exhibiting a significant asymmetry in the coordination sphere of Cu(I) owing to the presence of oxygen. In 2, the PF₆ ⁻ anion led to an interesting crystal packing with large open channels containing water. Finally, DFT calculations on a model of 3 showed that its HOMO exhibits, besides Fe, a significant Cu and Cl character, which is reflected in its electrochemical properties. Received July 14, 2000. Accepted July 21, 2000     

Synthesis of 4-Bromo-1,1′:4′,1″-terphenyl and 4-Methyl-1,1′:4′,1″-terphenyl

Russian Journal of Organic Chemistry - Possible synthetic routes to 4-bromo-1,1′:4′,1″-terphenyl and 4-methyl-1,1′:4′,1″-terphenyl have been studied. Stevens...     

Efficient synthesis of terminal 4-methylumbelliferyl labeled 5-fluoro-2′-deoxyuridine-5′-O-tetraphosphate (Um-PPPP-FdU): a potential probe for homogenous fluorescent assay

Efficient synthesis of 5-fluoro-2′-deoxyuridine-5′-O-tetraphosphate bearing 4-methylumbelliferyl label on the terminal phosphate is reported. This compound has the potential as a promising probe molecule for homogenous fluorescent polymerase assay. This class of compounds will aid in quantification of cellular internalization and DNA incorporation of nucleotide based chemotherapeutic agents to offer mechanistic insights.     

Highly stereoselective palladium-catalyzed Heck coupling of 5-iodouridine-5′-triphosphates with allylamine: a new efficient method for the synthesis of (E)-5-aminoallyl-uridine-5′-triphosphates

The palladium-catalyzed Heck coupling of 5-iodouridine-5′-triphosphates with allylamine is described. The reaction is highly stereoselective that results in high purity of (E)-5-aminoallyl-uridine-5′-triphosphate with good yields.     

Study of the inhibiting activity of 4-(4′-hydroxyphenyl)-and 4-(2′-hydroxy-5′-methylphenyl)methyl cyclohexane carboxylic acid ethyl esters in photooxidation of petroleum phosphors

4-(4′-hydroxyphenyl)-and 4-(2′-Hydroxy-5′-methylphenyl)methyl cyclohexane carboxylic acid ethyl esters were synthesized from phenol and para-cresol. The structure of the esters synthesized was studied, and their inhibiting activity in photooxidation of a petroleum phosphor produced from the heavy pyrolysis tar fraction was examined.     

Effect of solvent on the crystal structures of copper(II) complexes based on 4′-(4-methoxyphenyl)-2,2′:6′,2″-terpyridine and 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine

Four homoleptic copper(II) complexes, [Cu(Meophtpy)₂](ClO₄)₂ (Meophtpy = 4′-(4-methoxylphenyl)- 2,2′:6′,2″-terpyridine) (I), [Cu(Meophtpy)₂](ClO₄)₂ · 2H₂O (II), [Cu₂(m-Clphtpy)₄](ClO₄)₄ (m-ClPhtpy = 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine) (III), and [Cu₂(m-ClPhtpy)₄](ClO₄)₄ (IV) have been synthesized by hydrothermal methods and characterized by IR, elemental analysis and single crystal X-ray diffraction (CIF files CCDC nos. 963375 (I), 885457 (II), 963377 (III), and 963376 (IV)). Complex II is a polymorph of I and complex IV is a polymorph of III. All these complexes are obtained with 95% ethanol solution or 50% ethanol solution and the solvent control on the crystallization are obviously found. In all complexes, the face-to-face interactions between pyridyl rings or phenyl rings facilitate the construction of 3D network in the crystal in addition to hydrogen bonds. The fluorescence properties of these complexes have been investigated.     

Synthesis and Crystal Structure of 4-Phenyl-5-(1′- t-butyl-5′-methyl-4′-pyrazolyl)-1,2,4-triazol-3-thione

The crystal structure of 4-phenyl-5-(1′-t-butyl-5′-methyl-4′-pyrazolyl)-1,2,4-triazol- 3-thione 5 (C16H19N5S, Mr = 313.42) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 6.680(2), b = 27.44(1), c = 9.388(4)(A。), β = 106.738(6)°, V = 1648(1)(A。)3, Z = 4, Dc = 1.263 g/cm3, μ= 0.200 mm-1, F(000) = 664, R = 0.0608 and wR = 0.1176. The results confirmed that 5 can be assigned to the thione tautomeric form.     

Synthesis and applications of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene

The synthesis of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene 5a and 5b is described. The phosphorus atoms in (S)-(−)-5b are shown to be slightly more basic than the phosphorus atoms in (S)-BINAP by comparing the magnitude of the ¹J (³¹P–⁷⁷Se) coupling constant in their respective diselenide derivatives. (S)-(−)-5b behaved similarly to (S)-BINAP in asymmetric Heck reactions.     

Gram-scale synthesis of anti-pancreatic flavonoids (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-chrysin and -galangin

Gram-scale total synthesis of (±)-8-[1-(4′-hydroxy-3′-methoxyphenyl)prop-2-en-1-yl]-galangin (1) and -chrysin (2) has been accomplished in eight steps from commercially available phloroglucinol and three steps from commercially available chrysin, respectively, featuring an efficient introduction of C(8) (1-prop-2-en-1-yl)phenyl moiety in the natural products through chemo- and regioselective cinnamylation and regioselective aromatic Claisen rearrangement.     

Synthesis,characterization and in vitro antitumor behavior of a vanadium(V) complex with 4′-(3-methoxyphenyl)-2,2′:6′2″-terpyridine

A dioxovanadium(V) complex, [VO₂(moptpy)](ClO₄) (1, moptpy = 4′-(3-methoxyphenyl)2,2′:6′2″-terpyridine), was synthesized and characterized by elemental analysis, ESI-MS, UV–vis, IR, and ¹H, ¹³C, and ⁵¹V NMR. The cytotoxicity in vitro of 1 was evaluated against cancer cell lines HepG-2 (hepatocellular carcinoma), SGC-7901 (gastric carcinoma), SiHa (cervical cancer), BEL-7402 (hepatocellular), and rat PC-12 (pheochromocytoma) by the MTT method. The results demonstrated that 1 exhibits superior anticancer activity in vitro with much lower values of 50% inhibitive concentration (IC₅₀) against the selected cell lines than cisplatin, and 1 shows the highest cytotoxic activity toward SGC-7901 cells (IC₅₀ = 1.3 ± 0.1 μM) among the selected cell lines. A series of cellular morphological and staining experiments were carried out, and the results indicated that 1 can effectively induce apoptosis of SGC-7901 cells through a ROS-mediated mitochondrial dysfunction pathway. In addition, cellular incorporation and cell cycle analysis were also performed, and it was concluded from the experimental observations that 1 can efficiently enter into the cell nuclei, and the complex inhibits cell growth in SGC-7901 cell at G0/G1 phase.     

Molecular structure of 2,3-(4′-phenylacetyl)- and 2,3-(4′-diphenylacetyl)-benzo-15-crown-5

The conformational state of two benzo-crown ethers with substantially different physiological activity, 2,3-(4-phenylacetyl)- and 2,3-(4-diphenylacetyl)benzo-15-crown-5, was studied in crystals and solutions in CH₃CN and CCl₄ by x-ray crystallographic analysis, IR spectroscopy, and conformational calculations by the method of molecular mechanics. Transition from the crystalline state to solutions was found to be accompanied by a substantial change in the conformation of the macrocyclic ring of all the compounds studied. The nature of the substituent in the benzene ring and the polarity of the solvent have an influence on the conformational state of the macrocyclic ring of the free ligand, which, however, is not the determining factor in the change in the activity of the compounds. The COCCOC fragments of the macrocyclic framework are conformationally labile, readily passing from gauche to trans conformations and the reverse, which is promoted by the negligible energy barriers between the different conformations, determined in the work by a molecular mechanics method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1819–1825, August, 1991.     

Synthesis and properties of new functionalized poly(imides) based on 1,1-bis(4-aminophenyl)-1-z{4′-bis(4′’-bromophenyl)amino}phenyl-2,2,2-trifluoroethane

A new aromatic diamine, 1,1-bis(4-aminophenyl)-1-{4′-bis(4″-bromophenyl)amino}phenyl-2,2,2-trifluoroethane, is synthesized. Its interaction with various dianhydrides of aromatic carboxylic acids via high-temperature polycondensation yields a number of new functionalized poly(imides) combining high thermal and mechanical characteristics with solubility in organic solvents. The values of T _g vary from 208 to 230°C, and temperatures corresponding to 10% weight loss fall within the intervals 330–370 and 550–660°C (in air and argon, respectively). Spectroelectrochemical characteristics of poly(imides) are studied by cyclic voltammetry and UV-VIS spectrometry. Poly(imides) exhibit high reversible stability of electrochromic properties, and their color changes from colorless (the neutral form) to green (the oxidized form) as the applied potential is varied from 0 to 1.25 V.     

Understanding the role of flexible 4′-functionalized polyethylene glycoxy chains on the behavior of platinum(II) (4′-(ethylene glycoxy)-2,2′:6′,2′′-terpyridine: a kinetic and a mechanistic study

The ligand substitution kinetics of 4′-functionalized mononuclear Pt(II) (4′-(ethylene glycoxy)-2,2′:6′,2′′-terpyridine complexes, [Pt(nY-tpy)Cl)Cl] (where Y = ethylene glycoxy, n = number of ethylene, glycoxy units = 1, 2, 3, and 4, and tpy = 2,2′:6′,2′′-terpyridine), with thiourea, 1,3-dimethyl-2-thiourea, 1,1,3,3-tetramethyl-2-thiourea, and iodide were investigated under pseudo-first-order conditions as a function of concentration and temperature by conventional stopped-flow technique. The observed first-order rate constants followed the simple rate law k_obs = k₂[Nu]. The data obtained show that the ethylene glycoxy pendant, trans to the leaving group, acts as a σ-donor into the terpyridine ligand and is effective only up to n = 1, beyond which the substitution reactivity of the complexes are controlled by the steric influence of the appended ethylene glycoxy pendant units, which decreases with increase in the number of ethylene glycoxy units. The activation parameters obtained support an associative mechanism, where bond formation in the transition state is favored. The observed reactivity trends were supported by density functional theory calculations.