- STUDIES OF THE REACTIONS OF TRIAMINOPHOSPHINES WITH α,β-UNSATURATED NITRILES
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Tris(dialkylamino)phosphines IIIa and IIIb react with furfurylidenemalonitrile (Ia) and its thiophene analogue Ib to give a mixture of 1:1 adducts IV and V.Compounds IV have aminophosphonium dipolar ion structure, while compounds V are the ylide forms.The ratio of the products depends on the reaction conditions.Some reactions of IV and V are described.
- Hennawy, Ibtisam T.
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Read Online
- Formation of the fullerene radical anion in the reaction of C60 with phosphorous triamides
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Fullerene C60 reacts with phosphorous acid triamides to give the radical anion.
- Romanova,Mironov,Larionova,Morozov,Zverev,Sinyashin
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Read Online
- Experimental study of speciation and mechanistic implications when using chelating ligands in aryl-alkynyl Stille coupling
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Neutral palladium(ii) complexes [Pd(Rf)X(P-L)] (Rf = 3,5-C6Cl2F3, X = Cl, I, OTf) with P-P (dppe and dppf) and P-N (PPh2(bzN)) ligands have chelated structures in the solid-state, except for P-L = dppf and X = Cl, were chelated and dimeric bridged structures are found. The species present in solution in different solvents (CDCl3, THF, NMP and HMPA) have been characterised by 19F and 31P{1H} NMR and conductivity studies. Some [Pd(Rf)X(P-L)] complexes are involved in equilibria with [Pd(Rf)(solv)(P-L)]X, depending on the solvent and X. The ΔH° and ΔS° values of these equilibria explain the variations of ionic vs. neutral complexes in the range 183-293 K. Overall the order of coordination strength of solvents and anionic ligands is: HMPA ? NMP > THF and I-, Cl- > TfO-. This coordination preference is determining the complexes participating in the alkynyl transmetalation from PhCCSnBu3 to [Pd(Rf)X(P-L)] (X = OTf, I) in THF and subsequent coupling. Very different reaction rates and stability of intermediates are observed for similar complexes, revealing neglected complexities that catalytic cycles have to deal with. Rich information on the evolution of these Stille systems after transmetalation has been obtained that leads to proposal of a common behaviour for complexes with dppe and PPh2(bzN), but a different evolution for the complexes with dppf: this difference leads the latter to produce PhCCRf and black Pd, whereas the two former yield PhCCRf and [Pd(CCPh)(SnBu3)(dppe)] or [Pd(CCPh)(SnBu3){PPh2(bzN)}]. This journal is
- Espinet, Pablo,Gallego, Ana M.,Marcos-Ayuso, Guillermo,Martínez-Ilarduya, Jesús M.,Martin-Alvarez, Jose M.,Pe?as-Defrutos, Marconi N.
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supporting information
p. 11336 - 11345
(2020/09/03)
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- Function of substituents in coordination behaviour, thermolysis and ligand crossover reactions of phosphine oxides
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Some selected aminophosphine oxides (AmPOs) of the type OP(NMe2)3, OPPh(NMe2)2, OP(NC2H4O)3, OPPh(NC2H4O)2 and their corresponding La(III) and Th(IV) complexes are synthesized and analyzed by FT-IR, 1H-NMR, 31P{1H}-NMR, elemental analysis and TGA data. The coordination behavior of AmPOs was compared with some of the known ligands that include trioctylphosphine oxide (TOPO), tributylphosphate (TBP) and diethylphosphite (DEP). Thermogravimetric analysis of these complexes showed a distinct decomposition trend either by a single step or multi-step elimination of ligand species, which are strongly dependent on the electronic and steric behaviour of substituents on the P=O group and the nature of the metal. Phosphine oxide based La(III) and Th(IV) complexes undergo three unique intermolecular ligand exchange reactions at room temperature: relative competition among phosphine oxides to form a strong complex by exchanging the weaker ligand and complete ligand transfer from La(III) to Th(IV) metal centers. Ligand crossover is well controlled by priority rules and the trend is TOPO > TBP > DEP > AmPO > Ph3PO. This tendency closely agrees with the stability constants of metal complexes. On comparison, Th(IV) complexes showed slightly higher stability than La(III) analogues.
- Pavankumar,Goud, E. Veerashekhar,Selvakumar,Kumar, S. K. Ashok,Sivaramakrishna, Akella,Vijayakrishna, Kari,Rao, C. V. S. Brahmananda,Sabharwal,Jha, Prakash C.
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p. 4727 - 4736
(2015/03/03)
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- Reactions of 1,1′-(azodicarbonyl)dipiperidine with organophosphorus reagents
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1,1′carbonyl)dipiperidine reacts with tris(dimethylamino)phosphine, trialkyl phosphites, phosphorus ylides, and Lawesson's reagents to give the phosphorodihydrazidic amide, oxadiazole, dihydropyridazine, ethylenic, and thicarbonyl products, respectively. The antibacterial and antifungal activities for the new compounds are reported. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Biological Evaluation.
- Boulos, Leila S.,Abdel-Malek, Hoda A.,El-Sayed, Naglaa F.,Moharam, Maysa E.
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experimental part
p. 225 - 237
(2012/03/26)
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- General and mild preparation of 2-aminopyridines
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A general and facile one-pot amination procedure for the synthesis of 2-aminopyridines from the corresponding pyridine-N-oxides is presented as a mild alternative to SNAr chemistry. A variety of amines and heterocyclic-N-oxides participate effectively in this transformation which uses the phosphonium salt, PyBroP, as a means of substrate activation.
- Londregan, Allyn T.,Jennings, Sandra,Wei, Liuqing
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scheme or table
p. 5254 - 5257
(2011/02/24)
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- Hydrogen bonding between solutes in solvents octan-1-ol and water
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The 1:1 equilibrium constants, K, for the association of hydrogen bond bases and hydrogen bond acids have been determined by using octan-1-ol solvent at 298 K for 30 acid-base combinations. The values of K are much smaller than those found for aprotic, rather nonpolar solvents. It is shown that the log K values can satisfactorily be correlated against αH 2?βH2, where αH 2 and βH2 are the 1:1 hydrogen bond acidities and basicities of solutes. The slope of the plot, 2.938, is much smaller than those for log K values in the nonpolar organic solvents previously studied. An analysis of literature data on 1:1 hydrogen bonding in water yields a negative slope for a plot of log K against αH 2?βH2, thus showing how the use of very strong hydrogen bond acids and bases does not lead to larger values of log K for 1:1 hydrogen bonding in water. It is suggested that for simple 1:1 association between monofunctional solutes in water, log K cannot be larger than about -0.1 log units. Descriptors have been obtained for the complex between 2,2,2-trifluoroethanol and propanone, and used to analyze solvent effects on the two reactants, the complex, and the complexation constant.
- Abraham, Michael H.,Gola, Joelle M. R.,Cometto-Muniz, J. Enrique,Acree, William E.
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experimental part
p. 7651 - 7658
(2011/02/25)
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- Extremely base-resistant organic phosphazenium cations
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A series of peralkylated polyaminophosphazenium cations exhibiting extraordinary base resistance under phase-transfer conditions were efficiently synthesized from readily available starting materials. Their half lives under these conditions exceed those of the most stable conventional organic cations by factors of up to 3000.
- Schwesinger, Reinhard,Link, Reinhard,Wenzl, Peter,Kossek, Sebastian,Keller, Manfred
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p. 429 - 437
(2008/09/19)
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- Process for arylating or vinylating or alkynating a nucleophilic compound
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The present invention concerns a process for arylating or vinylating or alkynating a nucleophilic compound. More particularly, the invention concerns arylating nitrogent-containing organic derivatives. The arylating or vinylating or alkynating process of the invention consists of reacting a nucleophilic compound with a compound carrying a leaving group and is characterized in that the reaction is carried out in the presence of an effective quantity of a catalyst based on a metallic element M selected from groups (VIII), (Ib) and (IIb) of the periodic table and at least one at least bidentate ligand comprising at least two chelating atoms, namely at least one oxygen atom and at least one nitrogen atom.
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- An yttrium-based system to evaluate Lewis base coordination to an lectropositive metal in a metallocene environment
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The unsolvated bimetallic yttrium complex (C5Me5)2Y(μ-Cl)Y(C5Me5 )2Cl (1) provides a convenient platform upon which to compare the coordination chemistry of oxygen-donor ligands and monomers with Lewis acidic metal ions. Reaction of 1 with 2 equiv of oxygen-containing substrates formed the monomeric complexes (C5Me5)2YCl(L) (L = THF (2), benzophenone (3), methyl methacrylate (4), ε-caprolactone (5), hexamethylphosphoramide (6), ε-caprolactam (7), 1-methyl-2-pyrrolidinone (8), N,N′-dimethylpropyleneurea (9)). Each of these readily crystallize, which allows comparison of the Y-O interaction in the solid state. The X-ray data show that the numerical values of the measured Y-O lengths decrease in the order THF > benzophenone > methyl methacrylate > ε-caprolactone > hexamethyl-phosphoramide > ε-caprolactam > 1-methyl-2-pyrrolidinone > N,N′-dimethylpropyleneurea, although these bond lengths span only a short range and some are the same within experimental error. In the case of e-caprolactam, a bis adduct, (C5Me5)2YCl(ε-caprolactam)2 (10), can be isolated from the reaction of 1 and excess ε-caprolactam. 1H NMR spectroscopy indicates that (C5Me5)2YCl(L)L′ ligand displacement reactions in solution with 2-9 follow a trend consistent with the bond lengths except for (C5Me5)2YCl(ε-caprolactam) (7), in which L participates in hydrogen bonding to the chloride.
- Evans, William J.,Fujimoto, Cy H.,Johnston, Matthew A.,Ziller, Joseph W.
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p. 1825 - 1831
(2008/10/08)
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- Empirical correlations involving calorimetric, thermogravimetric and infrared data for zinc halides adducts
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The use of the non-isothermal Coats-Redfern method to obtain the activation energy values for the processes ZnX2·2hmpa(c) → ZnX2(c)+2hmpa(g) (X = Cl, Br, I and hmpa = hexamethylphosphoramide), by using thermogravimetric data, gave the values 44; 94 and 215 kJ mol-1 for the given sequence of halides. These values correlated to the standard molar enthalpy of formation in the condensed phase for the same sequence of adducts: - 1596, - 1532 and - 1408 kJ mol-1, respectively, providing the equation: ΔfH°m = 1.086 × Ea - 1639.738, which shows a linear correlation between the thermodynamic and kinetic parameters for such solid adducts. The IR spectroscopy data for a series of adducts of zinc halides with amides enabled the acquisition of an equation to estimate the mean metal-ligand bond enthalpy 〈D〉(M-L) values: the spectroscopic data were adjusted to the expression 〈D〉(M-L) = α + β + Δν, where αand β are related to Lewis acidity and basicity coordination features, respectively, and Δν is the difference between C=O or P=O stretching vibrations of the coordinated and uncoordinated ligands. This equation was applied for 15 adducts, showing a deviation less than 10% from the thermochemical values.
- De Farias, Robson F.,Airoldi, Claudio,Scatena Jr., Hélio
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p. 1677 - 1681
(2008/10/08)
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- Chemoselective electrophilic oxidation of heteroatoms by hydroperoxy sultamst
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The synthesis of novel hydroperoxy sultams 1b-d and their potential as renewable chemoselective electrophilic oxidants for a wide range of nitrogen, sulfur, and phosphorus heteroatoms in nonaqueous media is described. Reactions of 1b,c with secondary amines 10f,g yielded the hydroxysultams 2b,c and nitrone 11f or radical 11g depending on the substrate and stoichiometry, while tertiary amines 10a-d gave amine oxides 11a-d. Compounds 1c,d oxidized various thioethers 12a-g to sulfoxides 13a-g smoothly that were isolated by chromatography in nearly quantitative yields. 1c was regenerated from 2c by treatment of the latter with acidified H2O2. Kinetic studies of the reaction of 1c with 1,4-thioxane 12f suggest that the reaction follows the second-order kinetics, first order in substrate and first order in oxidant with the second-order rate constant several orders of magnitude larger than that of the corresponding reaction with hydrogen peroxide and tert-butyl hydroperoxide without the need for any acid or heavy metal catalysts. The phosphines 14a,b were also oxidized by 1c to the respective phosphine oxides 15a,b readily in quantitative yields. The reactions may be conducted at ambient temperature or lower and appear to proceed via a nonradical mechanism. Reactions are sensitive to steric as well as electronic factors.
- Gelalcha, Feyissa Gadissa,Schulze, Baerbel
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p. 8400 - 8406
(2007/10/03)
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- Synergism by sublimation of volatile lanthanide β-diketonates
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The synergistic effect by sublimation manifests itself in an increase in the volatility of nonvolatile or slightly volatile compounds in the presence of highly volatile agents. In this study, manifestations of the synergistic effect are demonstrated by th
- Kuzmina, Natalia P.,Martynenko, Larissa I.,Chugarov, Nikolai V.,Zaitseva, Irina G.,Grigoriev, Andrei N.,Yakushevich, Andrei N.
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p. 158 - 162
(2008/10/08)
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- Fluorination of organochlorophosphorus compounds with alkali metal salts of perfluorinated complex anions. Part 2
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Alkali metal salts of perfluorinated complex anions were used to fluorinate a few selected organochlorophosphorus compounds in the presence and absence of a multifunctional etheral solvent. Together with oxidative products, low to moderate yields of the desired monofluorinated products were obtained.
- Farooq, Omar
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- Oxidation in organophosphorus chemistry: Potassium peroxymonosulphate
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Potassium peroxymonosulphate (Oxone) is used as an efficient, chemoselective and stereoselective oxidizing agent for a wide variety of phosphorous, phosphothio- and phosphoseleno-compounds.
- Wozniak, Lucyna A.,Stec, Wojciech J.
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p. 2637 - 2640
(2007/10/03)
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- Facile and chemoselective reduction of carboxylic acids to alcohols using BOP reagent and sodium borohydride
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Hydroxybenzotriazolyl esters, formed in situ from carboxylic acids and BOP reagent, react with sodium borohydride in THF to give alcohols in high yields. This method is convenient, rapid and chemoselective, with such functional groups as nitro, halide, nitrile, azido and ester being unaffected.
- McGeary, Ross P.
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p. 3319 - 3322
(2007/10/03)
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- Kinetics of Reaction of Diphenylphosphinic Dihydrazide with Electrophilic Reagents in the Presence of Organic Bases
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Kinetics of the reactions of diphenylphosphinic dihydrazide with mesityl isothiocyanate, phenyl isothiocyanate, and picryl chloride in the presence of nitrogen-, oxyden-, and sulfur-containing organic bases in benzene at 25°C are studied. Accelerating effect of nitrogen- and oxygen-containing bases in the reactions of diphenylphosphinic hydrazide with all the studied electrophilic reagents correlates with the ability of these catalysts to form hydrogen bonds (pKHB). Sulfur-containing compounds practically do not exhibit catalytic properties in the studied systems. With increasing substrate reactivity, the catalytic effect of organic catalysts decreases.
- Yanchuk
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p. 220 - 223
(2007/10/03)
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- Arylamidoalkyl-N-hydroxyurea compounds having lipoxygenase inhibitory activity
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The present invention provides certain (substituted carbocyclic aryl)amidoalkyl- and (substituted heterocyclic aryl)amidoalkyl-N-Hydroxy urea compounds which inhibit lipoxygenase enzyme activity and are thus useful in the treatment of allergic and inflammatory disease states.
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- ARYLAMIDOALKYL-N-HYDROXYUREA COMPOUNDS HAVING LIPOXYGENASE INHIBITORY ACTIVITY
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The present invention provides certain (substituted carbocyclic aryl)amidoalkyl and (substituted hetero cyclic aryl) amido alkyl-N-Hydroxy urea compounds which inhibit lipoxygenase enzyme activity and are thus useful in the treatment of allergic and inflammatory disease states
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- INTRA- AND INTER-MOLECULAR REACTIONS OF ALKYL THIOCYANATES WITH DERIVATIVES OF P(III) ACIDS IN PRESENCE OF CHLORIDE ION DONORS
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By the reaction of 2-(trimethylsiloxy) thiocyanate with phosphorus trichloride we synthesized 2-thiocyanatoethyl phosphorodichloridite, which under the action of dialkylamines or (dialkylamino)trimethylsilanes is converted into S-(2-chloroethyl) tetraalkylphosphorodiamidothioates.The reactions of ethyl thiocyanate with tributyl phosphite and butyl tetraethylphosphorodiamidite in presence of chlorotrimethylsilane give O,O-dibutyl S-ethyl phosphorothioite or S-ethyl tetraethylphosphorodiamidite, cyanotrimethylsilane, and butyl chloride.In the reaction of ethyl thiocyanate with hexaethylphosphorous triamide and chlorotrimethylsilane hexaethylphosphorothioic triamide, cyanotrimethylsilane, and ethyl chloride are formed.
- Kamalov, R. M.,Stepanov, G. S.,Ryzhikov, D. V.,Pudovik, M. A.,Pudovik, A. N.
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p. 1614 - 1619
(2007/10/02)
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- THE BEHAVIOUR OF PHENANTHRENEQUINONE DERIVATIVES TOWARDS ACYCLIC AMINOPHOSPHINES
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Tris(dimethylamino)phosphine (IIIa) and/or bis-dimethylaminophenyl-phosphine (IIIb) react with 9,10-dihydro(9-dicyanomethylene)phenanthrene-10-one (Ib) to produce 1:1 adducts which have the aminophosphonium dipolar ion structure (V) in the crystalline state and in solutions.The 1:1 adduct isolated from the reaction of IIIb with 9,10-phenanthrenequinonenmonoimine (Ic) has a similar dipolar structure (XII) in the crystalline state.Solutions of the latter contained the same molecular species (XII) in equilibrium with a cyclic aminophospholene species (XIII).Only decomposition products could be observed from the reaction of IIIa with Ic.The products in this case were the phosphoroamidate (X), 9,10-phenanthrenequinone (Ia) and phenanthroxazine XI.A mechanism is proposed to explain the formation of these compounds.Key words: Tris(dimethylamino)phosphine (IIIa); bis-(dimethylamino)-phenyl-phosphine (IIIb); 9,10-dihydro(9-dicyanomethylene)phenanthrene-10-one (Ib); 9,10-phenanthrenequinonemonoimine (Ic); phosphonium dipolar ions (V, XII); cyclic aminophospholene ring system (XIII); phenanthroxazine (XI); hexamethylphosphoroamidate (X).
- Zayed, M. F.,El-Khoshnieh, Y. O.,Boulos, L. S.
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p. 251 - 256
(2007/10/02)
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- PHENOL DERIVATIVES, PHARMACEUTICAL COMPOSITIONS CONTAINING THESE COMPOUNDS AND PROCESSES FOR THE PREPARATION OF THESE COMPOUNDS AND COMPOSITIONS
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Phenol derivatives of the formula (I) wherein A and B have the same or different meanings and each represent one of the groups ?C=C?, cis?CH=CH? or trans?CH=CH?, R1 is hydrogen, an optionally substituted alkyl or phenyl group or a cycloalkyl group, R2 is hydrogen, methyl or ethyl, R3 represents hydrogen, acetyl or propionyl, R4 has the same meaning as R3 or represents an alkyl group, R5 is a carboxylic or a hydroxy group or a functional derivative of such groups or R5 is a nitrile group and R6 is hydrogen, an alkyl group or the group OR4 which specifically inhibit 5-lipoxygenase and are useful in pharmaceutical compositions for prophylaxis and treatment of diseases due to the action of leukotrienes. The compounds are prepared by reacting suitable acetylene compounds or metal derivatives thereof with alkyl or aryl halides or by means of Wittig reactions optionally followed by transforming the member R5 into another carboxylic acid derivative. By hydrogenation A and B may be varied within the scope of the definition.
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- Rates and mechanism of the stoichiometric oxidations of organic sulphides to sulphoxides with the peroxomolybdenum complex MoO(O2)2HMPT
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Stoichiometric oxidations of various organic sulfides were performed in 1,2-dichloroethane at -15°C with the oxodiperoxocomplex MoO(O2)2-HMPT in the absence and in the presence of Hg(OCOCF3)2. The oxidation cata
- Ballistreri, Francesco Paolo,Failla, Salvatore,Spina, Emanuela,Tomaselli, Gaetano Andrea
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- Process for producing 1-beta-methylcarbapenem antibiotic intermediates
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A process for isomerizing an alpha methylated azetidinone alkyl ester to the corresponding beta-methyl isomer, which is an intermediate in the synthesis of 1-beta-methylcarbapenem antibacterial agents. The process involves treating the dianion of structure I, being the alpha isomer, with a P-H or S-H containing organic protic acid, organometallic Sn or Pb hydride, metallic cation salt or trialkyl borane, followed by quenching with an OH protic organic acid or mineral acid.
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- Phenol derivatives and pharmaceutical compositions containing these compounds
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Phenol derivatives of the formula STR1 wherein A and B have the same or different meanings and each represent one of the groups --C C--, cis--CH=CH-- or trans--CH=CH--, R1 is hydrogen, an optionally substituted alkyl or phenyl group or a cycloalkyl group, R2 is hydrogen, methyl or ethyl, R3 represents hydrogen, acetyl or propionyl, R4 has the same meaning as R3 or represents an alkyl group, R5 is a carboxylic or a hydroxy group or a functional derivative of such groups or R5 is a nitrile group and R6 is hydrogen, an alkyl group or the group OR4 which specifically inhibit 5-lipoxygenase and are useful in pharmaceutical compositions for prophylaxis and treatment of diseases due to the action of leukotrienes. The compounds are prepared by reacting suitable acetylene compounds or metal derivatives thereof with alkyl or aryl halides or by means of Wittig reactions optionally followed by transforming the member R5 into another carboxylic acid derivative. By hydrogenation A and B may be varied within the scope of the definition.
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- AFFINITIES OF CROWN ETHERS, GLYMES, AND POLYAMINES FOR ALKALI PICRATES IN TOLUENE. APPLICATION OF POLYMER-SUPPORTED LINEAR POLYETHERS.
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This work reports the measurements of K values for polyamines, glymes, a few glycols (including that of a long-chain polyethylene glycol, carbowax 6000), and some frequently used cation-binding ligands as complexers of lithium or sodium picrate in toluene as solvent. K values for different resins obtained with the same soluble ligand provide a comparison of the effectiveness of these resins in binding ionic solutes.
- Xu,Smid
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p. 3790 - 3796
(2007/10/02)
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- 1-Iodoacetylenes. Part 2. Formation Constants of their Complexes with Lewis Bases
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Formation constants of the complexes of 1-iodoacetylenes (1)-(8) with Lewis bases (9)-(15) have been measured in solution by i.r. spectrophotometry.The stoichiometry of the complexes, the influence of the solvent on the equilibrium position, the existence of linear free energy relationships in the series of iodinated Lewis acids RI, where R=I, Br, Cl, CN, and CCX, and the relation between i.r. frequency shifts and stability constants are discussed.With any electron donor, 1-iodoacetylenes form less stable complexes than those formed by iodine cyanide.With hard bases, iodocyanoacetylene (8) and ethyliodopropiolate (7) give complexes wich are, respectively, more stable than and as stable as those with iodine; however, iodine complexes with soft bases are more stable.This is rationalized, in terms of empirical acidity scales, by the necessity to correlate the thermodynamic and spectroscopic properties of the RI complexes by a double scale equation.
- Laurence, Christian,Queignec-Cabanetos, Michele,Wojtkowiak, Bruno
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p. 1605 - 1610
(2007/10/02)
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- Synthesis and characterization of novel penta- and hexacoordinated sulfur-containing spirocyclic tin(IV) complexes
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Reactions of bis(toluene-3,4-dithiolato)tin(IV), Sn(TDT)2 (2), with the bases dimethyl sulfoxide (Me2SO), hexamethylphosphoramide (HMPA), and triphenylphosphine oxide (Ph3PO) yield hexacoordinated spirocyclic neutral adducts. Hydroxide ion with 2 gives a hexacoordinated dianionic product. Various reactions of 2 with a variety of halide salts yield new spirocyclic pentacoordinated monoanionic compounds, [XSn(TDT)2]-[R4M]+ (M = N, P, As). Large cations tend to stabilize the complexes. Reversible color changes take place on heating the pentacoordinated derivatives. The substances are characterized by 1H NMR and tin-119m M?ssbauer spectroscopy. The isomer shift of the monohalo anions shows a decrease with halogen electronegativity consistent with electron withdrawal at the tin center. The quadrupole splitting (QS) values are in the range 1.06-1.44 mm s-1 for the pentacoordinated monoanions investigated. These low values, lower than many QS values for tetracoordinate tin(IV) compounds, are associated with rectangular-pyramidal geometries around tin, as found by X-ray diffraction studies on representative members.
- Sau, Arjun C.,Holmes, Robert R.,Molloy, Kieran C.,Zuckerman
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p. 1421 - 1427
(2008/10/08)
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- 5-(Pyridinyl)-6-(lower-alkyl)-2(1H)-pyridinones, 1,2-dihydro-2-oxo-5-(pyridinyl)-6-(lower-alkyl)nicotinic acids and lower-alkyl esters thereof, and cardiotonic use thereof
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1-R1 -6-(lower-alkyl)-5-(pyridinyl)-2(1H)-pyridinones or 1-R1 -1,2-dihydro-2-oxo-6-(lower-alkyl)-5-(pyridinyl)nicotinic acids or lower-alkyl esters thereof or pharmaceutically-acceptable acid-addition or cationic salts thereof are useful as cardiotonic agents, where R1 is hydrogen, lower-alkyl or lower-hydroxyalkyl. These compounds are prepared by hydrolyzing the corresponding 3-cyano compounds to produce the corresponding 3-carboxylic acids and then either by decarboxylating or esterifying the acids.
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- Dichlorotris(dimethylamino)phosphorane as Dehydration Reagent for the Preparation of Activated (-ONp, -OPcp, -NSu)Esters of N-Protected Multifunctional Amino Acids
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Dichlorotris(dimethylamino)phosphorane (5) is an excellent reagent for the preparation of the activated esters of N-protected amino acids 7-9.Besides 4-nitrophenyl-, pentachlorophenyl-, and N-hydroxysuccinimide esters of various N-protected amino acids, in the presence of HOBt benzyloxycarbonyl-threonine N-hydroxysuccinimide ester was obtained for the first time.
- Appel, Rolf,Glaesel, Ursula
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p. 3511 - 3516
(2007/10/02)
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- Trapping of carbanionic species synthesis of new salt-free ylids and phosphoranes
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Syntheses of new salt-free ylids and phosphoranes by addition of a trivalent phosphorus compound with dimethylacetylene dicarboxylate in presence of a trapping reagent are described. The results are consistent with trapping of carbanionic species.
- Burgada, Ramon,Leroux, Yves,El Khoshnieh
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p. 925 - 928
(2007/10/02)
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- Cyclobutyl substituted derivatives of prostaglandin analogs
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Novel C15 cyclobutyl analogs or derivatives of prostaglandins of the E-, A- and F-classes are useful modifiers of smooth muscle activity. The compounds have valuable pharmacological properties such as platelet antiaggregating agents, gastric antisecretory agents and brochodilating agents.
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- REACTIONS OF SULFUR DIOXIDE WITH AMINOPHOSPHINES
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The reactions of SO2 with tris-dimethylaminophosphine, bis-dimethylaminofluorophosphine, bis-dimethylaminochlorophosphine, dimethylaminodifluorophosphine, dimethylaminodichlorophosphine, 1,3-dimethyl-2-fluoro-1,3,2-diazaphospholidine and 1,3-dimethyl-2-chloro-1,3,2-diazaphospholidine have been investigated.The complex reactions are dominated by facile oxidation of the respective phosphine to phosphoryl and thiphosphoryl derivatives.The new heterocyclic phosphines CH3(O)F and CH3(S)F have been isolated and characterized by NMR, infrared, and mass spectrometry.
- Light, R. W.,Paine, R. T.
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p. 255 - 258
(2007/10/02)
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