Über Chalkogenolate. LVII. Untersuchungen über Thioameisensäuren 5. Darstellung und Eigenschaften von Estern der Dithioameisensäure

Esters of the trimeric dithioformic acid [HCS(SR)]₃ were prepared by interaction of K[HCS₂] with alkyl iodides (R = CH₃, C₂H₅). Orthoesters HC(SR)₃ and di-orthoesters of the monomeric dithioformic acid were formed by reaction of formic acid with thioles (RSH mit R = CH₃, C₂H₅, CH₂C₆H₅) or dithioles (HS? (CH₂)_n? SH with n = 2, 3,4). The prepared compound were characterised by different methods.     

Rotational and vibrational distributions of N2(C 3Πu) excited by state-selected Ar(3P2) and Ar(3P0) metastable atoms

The ESR method is used to study the oxidation kinetics of the CH₃, C₂H₅, n-C₄H₉, i-C₄H₉, s-C₄H₉, t-C₄H₉, n-C₆H₁₃, C₆H₁₁, C₆H₅CH₂, CH₃C₆H₄CH₂, and C₆H₅CH₂CH₂ radicals in methanol matrix at 87 K. The reaction kinetics are shown to be describable in terms of a time-dependent rate constant k(t). The contribution from the matrix relaxation to k(t) has been determined. The oxidation rate and the shape of the kinetic curve are independent of the type of the radical. Models interpreting the experimental data are discussed.     

Über Chalkogenolate. 127. Diester der Cyaniminodiameisensäure NC?N(CO?OR)2 mit R = CH3, C2H5 und C6H5. Thiolyse der Diester

On Chalcogenolates. 127. Diesters of Cyanimino Diformic Acid NC? N(CO? OR)₂, where R = CH₃, C₂H₅, and C₆H₅. Thiolysis of these Diesters The diesters NC? N(CO? OR)₂ have been prepared by reaction of the sodium salt of cyanamide with the corresponding chloroformic acid ester. The thiolysis of these esters yields H₂N? CS? NH? CO? OR. The compounds with R = CH₃, C₂H₅, and C₆H₅ have been characterized by means of diverse methods.     

Ferrocene Derivatives of Valine and Leucine

Methyl and ethyl esters of valine and leucine were reacted with ferrocenecarbaldehyde to obtain azomethines (C₅H₅)Fe(C₅H₄CH=NCHRCOOR′) whose reactions with sodium borohydride provide ferrocenylmethyl derivatives (C₅H₅)Fe(C₅H₄CH₂NHCHR⋅COOR′) [R=(CH₃)₂CH, (CH₃)₂CHCH₂; R′ = CH₃, C₂H₅]. The latter compounds react with sodium hydroxide to give, after treatment of the reaction mixtures with acetic acid, N-substituted amino acids (C₅H₅)Fe(C₅H₄CH₂NHCHRCOOH).__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 1046–1048.Original Russian Text Copyright © 2005 by Popova, Yurashevich, Cherevin, Gulevich, Reshetova, Knizhnikov.     

New Dinuclear Ru2(CO)4 Sawhorse‐Type Complexes Containing Bridging Carboxylato Ligands

The thermal reaction of Ru₃(CO)₁₂ with ethacrynic acid, 4‐[bis(2‐chlorethyl)amino]benzenebutanoic acid (chlorambucil), or 4‐phenylbutyric acid in refluxing solvents, followed by addition of two‐electron donor ligands (L), gives the diruthenium complexes Ru₂(CO)₄(O₂CR)₂L₂ ( 1 : R = CH₂O‐C₆H₂Cl₂‐COC(CH₂)C₂H₅, L = C₅H₅N; 2 : R = CH₂O‐C₆H₂Cl₂‐COC(CH₂)C₂H₅, L = PPh₃; 3 : R = C₃H₆‐C₆H₄‐N(C₂H₄‐Cl)₂, L = C₅H₅N; 4 : R = C₃H₆‐C₆H₄‐N(C₂H₄‐Cl)₂, L = PPh₃; 5 : R = C₃H₆‐C₆H₅, L = C₅H₅N; 6 : R = C₃H₆‐C₆H₅, L = PPh₃). The single‐crystal structure analyses of 2 , 3 , 5 and 6 reveal a dinuclear Ru₂(CO)₄ sawhorse structure, the diruthenium backbone being bridged by the carboxylato ligands, while the two L ligands occupy the axial positions of the diruthenium unit.     

Synthesis reactivity and electrochemical properties of substituted cyclopentadienyl cobalt (III) complexes

Cyclopentadienyl cobalt complexes (η⁵‐C₅H₄R) CoLI₂ [L = CO,R=‐COOCH₂CH=CH₂ (3); L=PPh₃, R=‐COOCH₂‐CH=CH₂ (6); L=P(p‐C₆H₄O₃)₃, R = ‐COOC(CH₃) = CH₂ (7), ‐COOCH₂C₆H₅ (8), ‐COOCH₂CH = CH₂ (9)] were prepared and characterized by elemental analyses, ¹H NMR, ER and UV‐vis spectra. The reaction of complexes (η⁵‐C₅H₄R)CoLI₂ [L= CO, R= ‐COOC(CH₃) = CH₂ (1), ‐COOCH₂C₆H₅(2); L=PPh₃, R=‐COOC (CH₃) = CH₂ (4), ‐COOCH₂C₆H₅ (5)] with Na‐Hg resulted in the formation of their corresponding substituted cobaltocene (η⁵‐C₅H₄R)₂ Co[R=‐COOC(CH₃) = CH₂ (10), ‐COOCH₂C₆H₅ (11)]. The electrochemical properties of these complexes 1–11 were studied by cyclic voltammetry. It was found that as the ligand (L) of the cobalt (III) complexes changing from CO to PPh₃ and P(p‐tolyl)₃, their oxidation potentials increased gradually. The cyclic voltammetry of α,α′‐substituted cobaltocene showed reversible oxidation of one electron process.     

Organische Phosphorverbindungen XXXVII. Darstellung und Eigenschaften von Bis-(dialkoxyphosphonyl-methyl)-, Bis-(alkoxyphosphinyl-methyl)-und Bis-(oxophosphoranyl-methyl)-phosphinsäureestern sowie der entsprechenden Säuren [1]

Bis-chloromethyl-alkyl-and - aryl-phosphine oxides, (CICH₂₎₂P(O)R, which are obtained by reaction of (CICH₂₎₂P(O)Cl with GRIGNARD reagents, undergo a MICHAELIS -ARBUSOV reaction when heated for several hours with trivalent phosphorus esters (phosphites, phosphonites, or phosphinites) at 170–180°C. The reaction affords bis-(dialkyloxyphosphonyl-methyl)-, bis (alkyloxyphosphinyl-methyl)-, and bis-(oxophosphoranyl-methyl)-, -alkyl- or -aryl-phosphine oxides, R(O)P[CH₂P(O)R′R″]₂ R = CH₃, C₂H₅, n-C₈H₁₇, n-C₁₂H₂₅, C₆H₅; R′ and R″ = C₂H₅O, C₄H₉O, C₆H₅, CH₃ in good yields. Conversion of the compounds containing alkyloxy groups to the free acids is achieved by refluxing with conc. HCl. Bis-(dihydroxyphosphonyl-methyl)-dodecylphosphine oxide, n-C₁₂H₂₅(O)P[CH₂P(O) (OH)_2]2, obtained by hydrolysis of the all-ethyl ester, titrates in aqueous solution as a tetrabasic acid with breaks at pH = 4 (two equivalents), pH = 6,9 (one equivalent) and pH = 9,6 (one equivalent). This acid, its disodium salt (m. p. 405–410°) and its tetrasodium salt (m.p. > 460°) are surface active and are excellent chelating agents. The ¹H- and ³¹P-NMR. spectra of all the compounds prepared are discussed.     

Über Chalkogenolate. 81. Untersuchungen über N-Hydroxydithiocarbamidsäure 3. Ester der N-Hydroxydithiocarbimidsäure und -carbamidsäure

On Chalcogenolates. 81. Studies on N-Hydroxy Dithiocarbamic Acid. 3- Esters of N-Hydroxy Dithiocarbimic Acid and Dithiocarbamic Acid The reaction between hydroxylamine, carbon disulfide, and alkyl halide leads to the corresponding ester of N-hydroxy dithiocarbimic acid HO? N?C(SR)₂ with R = CH₃, C₂H₅; R₂ = ? CH₂? CH₂? . The phenyl ester of N-hydroxy dithiocarbamic acid HO? NH? CS(SC₆H₅) has been prepared by reaction of hydroxylammonium chloride with the phenyl ester of chlorodithioformic acid. N-Methyl hydroxylammonium chloride reacts with carbon disulfide and alkyl iodide to form the corresponding ester of the dithiocarbamic acid HO? N(CH₃)? CS(SR) with R = CH₃, C₂H₅. The unstable compounds have been characterized by different methods.     

Studies on organophosphorus compounds XLVIII Synthesis of Dithioesters from P,S-Containing Reagents and Carboxylic Acids and Their Derivatives

2,4-Bismethylthio-1,3,2,4-dithiadiphosphetane 2,4- disulfide, IIa, is prepared from 0,0-dimethyldithiophosphoric acid, Ia, and P₄S₁₀ at 160°C. 2,4-Bis(4-phenoxyphenyl)-1,3,2,4- dithiadiphsophetane 2,4-disulfide, IIc, and 2,4-bis(4-phenylthiolophenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, IId, are prepared at l60°C from P₄ S₁₀ and diphenylether and diphenylsulfides, respectively. Carboxylic acids RCOOH(R = CH₃ C₂H₅, n-C₃H₇, n-C₄H₉, C₆H₅CH₂, C₆H₈) react with compound Ia at 130°C to give the corresponding methyl dithioesters. Carboxylic acids RCOOH (R = C₆H₈-CH₂, C₆H₈) react with compound Ib at 200°C for 15 min to give the corresponding ethyl dithioesters, while low boiling acids (R = CH₃, C₂H₈, n-C₃H₇) yielded mixtures of the corresponding ethyl dithioester and ethyl carboxylate. Carboxylic acid chlorides RCOCl (R = ClCH₂, C₂H₅, t-C₄H₅ C₆H₅CH₂, C₆H₅, P-NO₂C₆H₄) react with compound IIa at 80°C to give the corresponding methyl dithioesters in good yields. S-Substituted thioesters react with IIC at 85°C to give the corresponding dithioesters in good yields. Dihydro2(3H)-furanone, VI, and 5-methyl-2(3H)-furanone, VII, react with IIa at 80°C; to dihydro-2(3H)-thiophenethione, VIII and 2,2'-dithiobis(5-methyl thiophene),IX, respectively. Also XI reacts with IIa,IIc, and IId to give VIII in nearly quantitative yields.     

Triorganyltelluroniumcarboxylate

Triorganyltelluronium Carboxylates By reaction of triphenyltelluronium methoxyd or trimethyltelluronium hydroxyd with carboxylic acid, triorgayltelluronium carboxylates of the type R₃TeO₂CR′ (R ? CH₃, C₆H₅; R′ ? CH₃, CHCl₂, CCl₃, C₆H₅) are obtained. Another preparative method is the reaction of trimethyltelluronium iodide or triphenyltelluronium chloride with silver acetate.     

Optisch aktive übergangsmetall-komplexe LXIV. Neue optisch aktive Cp(CO)Fe-acyl-komplexe mit

The novel complexes CpFe(CO)(COR)P(C₆H₅)₂NR'R^* with Cp = C₅H₅,C₉H₇ (indenyl); R = CH₃, C₂H₅, CH(CH₃)₂, CH₂C₆H₅;R` = H, CH<sub>3</sub>, C<sub>2</sub>H<sub>5</sub>, CH<sub>2</sub>C<sub>6</sub>H<sub>5</sub> and R<sup>*</sup> = (S)-CH(CH<sub>3</sub>)(C<sub>6</sub>H<sub>5</sub>), have been synthesized by reaction of CpFe(CO)<sub>2</sub>R wiht P(C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>NR`R^* and characterized analytically as well as spectroscopically. The pairs of diastereoisomers RS/SS have been separated by preparative liquid chromatography and fractional crystallization, respectively. The optically pure complexes (+)₄₃₆- und ()₄₃₆-CpFe(CO)(COR)P(C₆H₅)₂NR`R^* are configurationally stable at room temperature. At higher temperatures they equilibrate with CpFe(CO)₂R and epimerize with respect to the Fe configuration.     

Coordination compounds of indium : XXXVI. The direct electrochemical synthesis of neutral and anionic organoindium halides

The electrochemical oxidation of indium metal in cells of the type leads to the formation of RInX₂ compounds; if 2,2′-bipyridine is also present, the products are the adducts RInX₂·bipy (R = CH₃, C₂H₅, C₆H₅, C₆H₅CH₂, C₆F₅; X = Cl, Br, I (not all combinations)). When R′₄NX is present instead of bipy, the products are the salts R′₄N[RInX₃]. The electrochemical oxidation apparently proceeds via the general mechanism discussed previously. Anomalous results with CH₃I or C₂H₅I are discussed in the light of the known solution chemistry of organoindium(III) compounds.     

Reactions of alkylcobalt complexes containing a tetradentate nitrogen-donating ligand

The reactions of RCo(BDM1,3pn)(H₂O) with light, heat, acids, electrophiles and nucleophiles were studied. (HBDM1,3pn is a mononegative, tetradentate dioxime-diimine ligand formed by condensing 2,3-butanedionemonoxime with 1,3-propanediamine in a 2/1 molar ratio; R = CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, and C₆H₃CH_2-) Pyrolysis and photolysis of the alkyl complexes result in a cobalt(II) complex (anaerobic conditions) along with alkenes and alkanes. The major organic products from solid state pyrolysis at 200°C or photolysis in water are CH₄ (R = CH₃), C₂H₄ (R = C₂H₅), C₃H₆ (R = n-C₃H₇), C₄H₈ (R = n-C₄H₉) and (C₆H₅CH₂)₂ (R = C₆H₅CH₂). No alkyl—cobalt bond cleavage occurs with acids or bases in most cases. Two exceptions are the reactions with 3 M HNO₃ at 25°C and with 1 M NaOH at 52°C. Electrophiles like I₂ cleave the alkyl—cobalt bond forming RI and Co^III (BDM1,3pn)I₂. Nucleophilic reagents (N^-) displace the H₂O trans to the alkyl group to form RCo(BDM1,3pn)(N), but do not dealkylate the alkyl complex under the reaction conditions studied.     

Synthesis and Characterization of Diphenyltin(IV) Dicarboxylates Containing Germanium

Twelve new germanium substituted diphenyltin dipropionates with the general formula (R¹GeCHR²‐CHR³COO)₂SnPh₂ where R¹ = N(CH₂CH₂O)₃, (C₆H₅)₃ and (CH₃C₆H₄)₃, R² = H, CH₃, C₆H₅, p‐CH₃C₆H₄, p‐CH₃OC₆H₄, p‐ClC₆H₄, and R³ = H, CH₃ have been synthesized by the reaction of diphenyltin oxide with a germanium substituted propionic acid. All the compounds were characterized by elemental analysis, IR, multi‐nuclear (¹H, ¹³C, ¹¹⁹Sn) NMR and Mössbauer spectroscopies as well as mass spectrometry. The in vitro antibacterial activity of selected compounds is also reported.     

Über die Reaktion von Schwefel mit Aminen und Formaldehyd. Eine neue Methode zur Herstellung von Thioformamiden und Dithiocarbamaten

The reaction of sulfur with primary or secondary amines and formaldehyde has been studied. A simple one step process for the preparation of thioformamides (RR′NCHS; R ? H, R′ ? CH₃, C₂H₅; R ? R′ ? CH₃, C₂H₅; R+R′ ? ? (CH₂), ? (CH₂), ? C₂H₄OC₂H) and the amine salts of N, N-dialkyl-dithiocarbamic acids (R₂NCS₂ · H₂NR₂, R ? CH₃, C₂H₅, C₄H₉; R₂ ? ? (CH₂), ? (CH₂), ? C₂H₄OC₂H) is reported. In addition, the isolation of diethylamidosulfoxylic acid, (C₂H₅)₂NSOH · 1/2 H₂O, the first derivative of a new class of compounds, is described. The physical properties and the ¹H-NMR. spectra of the above mentioned compounds are given.     

Kinetics and Mechanism of the Oxidation of 4-Oxo-4-arylbutanoic Acids by N-bromophthalimide in Aqueous Acetic Acid Medium

The kinetics of oxidation of a series of substituted 4-oxobutanoic acids (Y–C₆H₄COCH₂CH₂COOH: Y = H, OCH₃, CH₃, C₆H₅, Cl, Br or NO₂) by N-bromophthalimide have been studied in aqueous acetic acid medium at 30 °C. The total reaction is second-order, first-order each in oxidant and substrate. The oxidation rate increases linearly with [H⁺], establishing the hypobromous acidium ion, H₂O⁺Br, as the reactive species. A variation in ionic strength has no effect on the reaction rate. The order of reactivity among the studied 4-oxoacids is: 4-methoxy > 4-methyl > 4-phenyl > 4-H > 4-Cl > 4-Br > 3-NO₂. The effect of changes on the electronic nature of the substrate reveals that there is a development of positive charge in the transition state. The activation parameters have been computed from Arrhenius and Eyring plots. Based on the kinetic results, a suitable mechanism has been proposed.     

Reactions of (η5-C5H5)2Tir compounds with organic cyanides

The syntheses and properties of the titanium(III) complexes Cp₂Tir · R′CN (R = C₆H₅, o-, m-, p-CH₃C₆H₄, CH₂C₆H₅, C₆F₅, Cl; R′ = CH₃, t-C₄H₉, C₆H₅, o-CH₃C₆H₄, 2,6-(CH₃)₂C₆H₃) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).     

Coupling of Phenol with Ketones in the Presence of Heteropoly Acids with Different Structures and Compositions

The reactions of phenol coupling with ketones MeCOR (R = CH₃, C₂H₅, C₃H₇, and C₄H₉) are studied in the presence of heteropoly acids with different structures and compositions in toluene solutions ([PhOH]/[MeCOR] = (2–8)/1 mol/mol; 50–70°C) with thioglycolic acid added as a promoter. The reaction rate depends on ketone and heteropoly acid, and the yield of bisphenols is as high as 24–72%. The reaction orders are 0.68, 0.77, and 0.97 with respect to H₆P₂W₂₁O₇₁, H₃PW₁₂O₄₀, and H₄SiW₁₂O₄₀, respectively, and the activation energies are 25.1, 21.0, and 20.6 kcal/mol, respectively. Heteropoly acids of the Dawson structure exhibited the highest activity.     

Alcoholysis of (2-methoxycarbonyl)ethyltin compounds

Under acid or base catalysis, di(2-alkoxycarbonylethyl)tin dichlorides of various R groups, (ROCOCH₂CH₂)₂SnCl₂, can be prepared conveniently in high yield by alcoholysis of (CH₃OCOCH₂CH₂)₂SnCl₂ in various alcohols, ROH (R = C₂H₅, C₄H₉, iso-C₄H₉, C₅H₁₁, C₆H₅CH₂, C₄H₉CH(C₂H₅)CH₂). When excess acid or base is present in the aqueous solution, (ROCOCH₂CH₂)₂SnCl₂ eliminate ROH and precipitate as C₆H₈O₄Sn regardless of the R group. C₆H₈O₄Sn can be converted into various (ROCOCH₂CH₂)₂SnCl₂ derivatives on dissolving in alcoholic HCl solutions.     

The electrophilic addition of thiols to olefins: A theoretical and experimental study

Density functional theory with the B3LYP hybrid functional and 6–31G* basis set was used to study the geometric and electronic structure of H₂C = CHR (R = H, CH₃, C₂H₅, C₃H₇, C₄H₉, and C₅H₁₁) olefins, their carbocations formed in the addition of the proton to the olefins, R′-S-H aliphatic thiols (R′ = H, CH₃, C₂H₅, and C₃H₇), the products of the addition of thiols to carbocations, and the final products of the addition of thiols to olefins. The proton affinity of the olefins and the products of the addition of thiols to olefins was calculated. The conclusion was drawn that the limiting stage in the nonradical addition of thiols to olefins catalyzed by acids was proton transfer from the protonated reaction product to the olefin. The theoretical results were compared with the experimental data on the electrophilic addition of polymercaptan to heptene-1.