Showing papers in "Bulletin of the Chemical Society of Japan in 1984"
TL;DR: In this article, the relation between the anisotropy of the band structure and the arrangement of the organic molecules is investigated for two organic donors, tetrathiafulvalene (TTF) and bis(ethylenedithio)tetrathyfulvalenes (BEDT)-TTF, based on the extended Huckel molecular orbital calculations.
Abstract: Based on the extended Huckel molecular orbital calculations, the relation between the anisotropy of the band structure and the arrangement of the organic molecules is investigated for two organic donors, tetrathiafulvalene (TTF) and bis(ethylenedithio)tetrathiafulvalene (BEDT–TTF). The intermolecular overlaps of their HOMO are calculated while the intermolecular arrangements are varied. The maps of the overlaps thus obtained are then used to estimate the band-structure parameters of (TMTTF)2X and (BEDT–TTF)2ClO4(C2H3Cl3)0.5. The Fermi surface of (TMTTF)2X is quasi-one-dimensional and not closed. On the contrary, (BEDT–TTF)2ClO4(C2H3Cl3)0.5 is regarded as a two-dimensional semimetal.
644 citations
TL;DR: Partition equilibria of alkali TFPB between water and organic solvents and the stability in acid media are described and compared with the properties of the parent tetraphenylborate and of some fluorine-containing homologues as discussed by the authors.
Abstract: Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) anion was highly lipophilic, practically insoluble in water, and durable against acid and oxidants. Partition equilibria of alkali TFPB between water and organic solvents and the stability in acid media are described and compared with the properties of the parent tetraphenylborate and of some fluorine-containing homologues.
311 citations
TL;DR: In this article, the decay of some radical pairs in micellar solutions under high magnetic fields is interpreted in terms of the relaxation mechanism, and the magnetic field dependence of their relaxation rates is calculated for a model system.
Abstract: External magnetic field and magnetic isotope effects on the dynamic behavior of radical pairs in solutions have been studied theoretically, where the relaxation of their electron spins was taken into account. The decay observed with some radical pairs in micellar solutions under high magnetic fields is successfully interpreted in terms of the relaxation mechanism, and the magnetic field dependence of the relaxation rates is calculated for a model system.
225 citations
TL;DR: In this article, basic properties of polyaniline (PA) deposited anodically on platinum electrodes have been studied on the following points: 1) Effect of the mode of electrolysis and supporting electrolytes in the film forming process, 2) Characteristics of charging-discharging processes.
Abstract: Basic behaviors and properties of polyaniline(PA) deposited anodically on platinum electrodes have been studied on the following points. 1) Effect of the mode of electrolysis and supporting electrolytes in the film forming process. 2) Characteristics of charging-discharging processes. 3) Electric conductivity and elemental composition of PA. The different modes of electrolysis do not affect the characteristics of the PA electrode obtained. The growth rate of PA film is 2.7–2.8 times faster in sulfuric acid than in perchloric, nitric or hydrochloric acid. It is indicated that there are two types of doping; one is associated with the acid-base equilibrium between amino or imino group in the film and proton in the solution and the other is associated with the excess charge in the film produced by anodic oxidation. The electric conductivity of PA markedly decreases by the immersion in alkali solutions. The release of doped anion from PA by treating with an alkali solution is confirmed by the elemental analysi...
163 citations
TL;DR: Palladium compounds such as Pd(PPh3)4 as discussed by the authors catalyze polycondensation between dihalo aromatic compounds, X-Ar-X (Ar=p-phenylene, 2,5-thiophenediyl, 9,10-anthracenediyl, 2.6-pyridinediyl), p-benzenedicarbonyl, p-xylene-α,α′-diyl), and acetylenic compounds (p-C6H4(C≡CH)2 or p-
Abstract: Palladium compounds such as Pd(PPh3)4 and Pd(OAc)2 catalyze polycondensation between dihalo aromatic compounds, X–Ar–X (Ar=p-phenylene, 2,5-thiophenediyl, 9,10-anthracenediyl, 2,6-pyridinediyl, p-benzenedicarbonyl, p-xylene-α,α′-diyl), and acetylenic compounds (p-C6H4(C≡CH)2 or p-C6H4(C≡CMgBr)2). The polymers obtained have high thermal stabilities and most of them show fluorescence. One of the polymers is converted into semiconductors by doping with electron acceptors.
124 citations
TL;DR: In this paper, the apparent molal volumes (φV), apparent mollal adiabatic compressibilities (σ), and relative viscosities (nr) at 25 °C have been obtained for the following amino acids in aqueous alkali-chloride solutions from measurements of the density, the ultrasonic velocity, and the flow time: glycine, L-alanine, β-aline, α-aminoisobutyric acid, l-serine, and L-threonine.
Abstract: The apparent molal volumes (φV), apparent molal adiabatic compressibilities (φKS), and relative viscosities (nr) at 25 °C have been obtained for the following amino acids in aqueous alkali-chloride solutions from measurements of the density, the ultrasonic velocity, and the flow time: glycine, L-alanine, β-alanine, α-aminoisobutyric acid, L-serine, and L-threonine. Viscosity measurements were also carried out in water for reference. The alkali chlorides used were lithium, sodium, and potassium chlorides. The limiting values φVo, φKSo and the extended Jones-Dole viscosity coefficients, B and D, were calculated by a linear extrapolation using the least-squares method. All the φVo, φKSo, and B values obtained in the mixed solvents were larger than the corresponding ones in water, except in a few cases of the B coefficient. The results are discussed in terms of the dehydration effect of the electrolytes upon the amino acids.
123 citations
TL;DR: In this article, the reaction of tributyltin enolates, prepared from tributnyltin methoxide and enol acetates in situ, with aryl and 1-alkenyl bromides in the presence of dichlorobis(tri-o-tolylphosphine)palladium w...
Abstract: The reaction of tributyltin enolates, prepared from tributyltin methoxide and enol acetates in situ, with aryl and 1-alkenyl bromides in the presence of dichlorobis(tri-o-tolylphosphine)palladium w...
107 citations
TL;DR: In this paper, a series of 1-alkynes (RC≡CH where R=Et, nPr, n-Bu, N-C6H13, cyclohexyl, Ph, Me3Si, ME3SiCH2, and Me3 SiOCH2) was found to dimerize regioselectively (>99%) to 2,4-disubstituted 1-buten-3-ynes in 92-99% yields by catalysis of (η5-C5Me5)2TiCl2
Abstract: A series of 1-alkynes (RC≡CH where R=Et, n-Pr, n-Bu, n-C6H13, cyclohexyl, Ph, Me3Si, Me3SiCH2, and Me3SiOCH2) was found to dimerize regioselectively (>99%) to 2,4-disubstituted 1-buten-3-ynes in 92–99% yields by catalysis of (η5-C5Me5)2TiCl2/i-PrMgBr at 30 °C in 1–3 h. The catalyst system is also effective for the regioselective codimerization of various 1-alkynes with 1-ethynylcyclohexene or ethynylbenzene.
106 citations
TL;DR: In this paper, the rate and products of oxidation of methyl linoleate dispersed in water by Triton X-100 were measured at 50 °C, and the oxidation proceeded smoothly by both types of initiators without any noticeable induction period.
Abstract: The rate and products of oxidation of methyl linoleate dispersed in water by Triton X-100 were measured at 50 °C. The oxidation was initiated by water- or oil-soluble azo-initiators. The oxidation proceeded smoothly by both types of initiators without any noticeable induction period and a constant rate of oxygen uptake was observed. Conjugated diene hydroperoxides were formed almost quantitatively. The oxidizability for methyl linoleate in aqueous dispersion was obtained as kp/(2kt)1⁄2=0.032(s·mol/L-oil)−1⁄2 where kp and kt are the rate constants for propagation and termination reactions, respectively. This value was similar to that observed in the homogeneous oxidation in chlorobenzene. L-Ascorbic acid inhibited the oxidation initiated by water-soluble initiator but it could not inhibit the oxidation initiated by oil-soluble initiator. 2,6-Di-t-butyl-4-methylphenol inhibited the oxidation initiated by both initiators. On the other hand, α-tocopherol was effective for the oxidation initiated by oil-solubl...
100 citations
TL;DR: In this paper, the analysis of the diffraction intensity of liquids obtained by the energy-dispersive method has been revised and improved, and a new method for determining the energy spectrum of the primary beam is presented.
Abstract: The procedure of the analysis of the diffraction intensity of liquids obtained by the energy-dispersive method has been revised and improved. A new method for determining the energy spectrum of the primary beam is presented. The escape correction, the slit correction and the correction for multiple scattering have been newly applied. Scattering of X-rays from liquid CCl4 has been measured and its structure function has been obtained by an improved procedure.
99 citations
TL;DR: In this paper, the propargyltitanium reagents derived from 1-alkylpropyne condensed with aldehydes were used to give α-allenyl alcohol regioselectively.
Abstract: The propargyltitanium reagents derived from 1-alkylpropyne condensed with aldehydes to give α-allenyl alcohol regioselectively, while the allenyltitanium reagents generated from 1-alky1-1-butyne derivatives gave threo-β-acetylenic alcohols with high regio- and stereoselectivities. The course of the reaction was determined by the substitution pattern of starting alkynes. The similar reactions of metallated 1,3-bis(trialkylsilyl)propyne or (trialkylsilyl)acetonitrile with aldehydes were also investigated.
TL;DR: In this paper, the transfer of tetramethylammonium (TMA+) ion across the interface between LiCl aqueous solution and a 0.1 mol dm−3 tetrabutyammonium tetraphenylborate nitrobenzene solution was investigated by means of phase-selective a.c. polarography.
Abstract: The transfer of tetramethylammonium (TMA+) ion across the interface between a 0.1 mol dm−3 LiCl aqueous solution and a 0.1 mol dm−3 tetrabutylammonium tetraphenylborate nitrobenzene solution was investigated by means of phase-selective a.c. polarography. In recording the a.c. polarographic current a two-electrode cell system was used and the ohmic drop due to solution resistance in the cell was compensated for by positive feedback. The ion-transfer admittance vs. potential curves were determined in the a.c. frequency range between 10 and 100 Hz and the kinetic parameters of the TMA+-ion transfer across the water/nitrobenzene interface were determined.
TL;DR: The sign of the centro-chirality of the product amino acids was always the same to that of the axial chirality in both cases of BDPAB and Me-BDPAB as mentioned in this paper.
Abstract: Axially dissymmetric bisphosphine ligands, (R)- and (S)-2,2′-bis(diphenylphosphinoamino)-1,1′-binaphthyl (BDPAB) and (R)-2,2′-bis[N-(diphenylphosphino)methylamino]-1,1′-binaphthyl (Me-BDPAB) were conveniently prepared from 2,2′-diamino-1,1′-binaphthyl The rhodium(I)-catalyzed asymmetric hydrogenation of α-acylamidoacrylic acids and esters gave the corresponding amino acids of up to 95% optical purity The sign of the centro-chirality of the product amino acids was always the same to that of the axial chirality of the ligand in both cases of BDPAB and Me-BDPAB
TL;DR: In this article, the effect of solvents on the reduction of esters was examined with readily available sodium borohydride which is known to be incapable of reducing such functional groups.
Abstract: The effect of solvents on the reduction of esters was examined with readily available sodium borohydride which is known to be incapable of reducing such functional groups. In mixed solvents of t-butyl alcohol–methanol or tetrahydrofuran–methanol, various carboxylic esters and lactones were found to be reduced by sodium borohydride to the corresponding alcohols or diols in high yields. Slow addition of methanol to the refluxing mixture of ester and sodium borohydride in t-butyl alcohol or tetrahydrofuran was essential to achieve effective reduction. On the other hand, each individual solvent, methanol or t-butyl alcohol, was not effective for the reduction. The procedure provided a practical method for the functional group selective reduction of esters in the presence of chloro, cyano, carboxylato, carbamoyl, carboxy or nitro groups, which can not usually be performed by lithium aluminium hydride.
TL;DR: In this article, the change in film color which occurs in the redox reaction of the film was investigated in detail as a function of electrode potential and the charge consumed in the reaction.
Abstract: Polypyrrole films prepared by anodic polymerization of pyrrole on Pt or SnO2-coated glass show redox behavior in aqueous electrolyte solutions containing a supporting electrolyte alone. Transfer of electrolyte anions into and from the film is involved in the redox reaction similarly with acetonitrile solutions already reported. Insertion of divalent anions into the film occurs in two steps but that of monovalent anions in one step, as judged from corresponding cyclic voltammograms. The change in film color which occurs in the redox reaction of the film was investigated in detail as a function of electrode potential and the charge consumed in the redox reaction. Polypyrrole is a promising material for electrochromic display devices.
TL;DR: In this paper, a facile and direct preparation of 2-hydroxyisophthalaldehydes from 2,6-bis(hydroxymethyl) phenols using activated manganese(IV) oxide is described.
Abstract: A facile and direct preparative method of 2-hydroxyisophthalaldehydes from 2,6-bis(hydroxymethyl) phenols using activated manganese(IV) oxide is described. The aldehydes are obtained in good yields.
TL;DR: In this paper, various nitroarenes having chloro, methyl, or methoxy substituents were reduced to the corresponding aminoarenes in high yields using formic acid in the presence of a catalytic amount of RuCl2(PPh3)3.
Abstract: Various nitroarenes having chloro, methyl, or methoxy substituents were reduced to the corresponding aminoarenes in high yields using formic acid in the presence of a catalytic amount of RuCl2(PPh3)3. For example, 4-chloronitrobenzene was converted in 99% conversion with 98% selectivity at 125 °C for 5 h. 4-Nitroacetophenone was reduced chemoselectively to 1-(4-nitrophenyl)ethanol in 74% isolated yield under the same reaction conditions. Formic acid could also be employed as reductant for hydrogenation of heterocyclic compounds such as quinoline, indole, and quinoxaline in the presence of the ruthenium catalyst. 2-Methylquinoline was hydrogenated to 1,2,3,4-tetrahydro-2-methylquinoline in 93% conversion with 100% selectivity.
TL;DR: In this paper, the authors showed that the fluorescence yield and fluorescence lifetime of 7-ethoxycoumarins in aqueous solutions are reduced with the increase in the temperature and in the concentration of the quenching agents.
Abstract: The fluorescence yield and the fluorescence lifetime of 7-ethoxycoumarins in aqueous solutions are reduced with the increase in the temperature and in the concentration of the quenching agents. The radiationless deactivation of the excited state in the absence of quenchers is temperature-dependent; its activation energy has been determined to be 32.5–34.8 kJ mol−1. The quenching reaction due to halide ions proceeds via both a diffusional and a static process. The rate constant for the diffusional process has a value of (9.7–10.2)×109 mol−1 dm3s−1 in the case of I− as a quencher. The static quenching component can be approximately described by the V[Q] expression, with the static quenching constant, V, being 1.6–1.8 mol−1 dm3. The quenching efficiencies that represent the probability leading to real quenching reactions by an encounter of the molecule and the halide ion are unity for I−, 0.39–0.42 for Br−, and almost zero for Cl−. The possible physical interpretation of the quenching mechanism is discussed ...
TL;DR: In this article, a new indole synthesis starting with o-methylphenyl isocyanides such as o-tolyl, 2,4-oxylyl and 2,6-xylyl was described in full detail.
Abstract: New indole synthesis starting with o-methylphenyl isocyanides such as o-tolyl, 2,4-xylyl, and 2,6-xylyl isocyanide is described in full detail. Treatment of o-tolyl isocyanide with LDA in diglyme at −78 °C generated selectively o-(lithiomethyl)phenyl isocyanide in an almost quantitative yield, which on warming up to room temperature was cyclized to indole after aqueous workup. Similary, 2,4-xylyl and 2,6-xylyl isocyanides were cyclized to 5-methylindole and 7-methylindole quantitatively. The o-(lithiomethyl)phenyl isocyanides reacted with electrophiles such as alkyl halides and alkylene oxides to give o-alkylphenyl isocyanides, which were cyclized via the lithiation at the orthobenzylic carbon to afford 3-substituted indoles. On the other hand, the o-(lithiomethyl)phenyl isocyanides generated in situ at −78 °C was first warmed up to room temperature and then treated with electrophiles to furnish 1-substituted indoles. The o-(lithiomethyl)phenyl isocyanides were acylated in a fairly good yield with N-acyla...
TL;DR: In this article, the fundamental kinetic equations for nonisothermal crystal growth from preexisting nuclei are derived, by introducing a concept of reduced time, and all kinetic parameters can be estimated by the method, so that the process proceeding under various temperature changes can also be predicted.
Abstract: Fundamental kinetic equations for nonisothermal crystal growth from preexisting nuclei are derived, by introducing a concept of reduced time. A method of kinetic analysis of thermoanalytical data of these processes is proposed, and all kinetic parameters can be estimated by the method, so that the process proceeding under various temperature changes can also be predicted.
TL;DR: The rate of thermal cis-to-trans isomerization of 4-dimethylamino-4-nitroazobenzene(NDAAB) derivatives has been studied in this paper.
Abstract: The substituent, solvent, and pressure effects on the rate of the thermal cis-to-trans isomerization of 4-dimethylamino-4′-nitroazobenzene(NDAAB) derivatives have been studied. 2-Methyl- and 2′-chloro–NDAAB isomerize faster than NDAAB, and 2′-methyl- and 2-chloro-NDAAB isomerize slower than NDAAB. For 2,2′-dimethyl- and 2,2′-dichloro-NDAAB, the rates are between those of the monosubstituted ones. These findings are very similar to those for 4-(dimethylamino)azobenzene (DAAB) derivatives, and no fundamental difference in the kinetic-substituent effects was observed between NDAAB and DAAB. The volume of activation, which is of a negative value, varies remarkably from solvent to solvent and from substituent to substituent; its magnitude increases generally with an increase in the solvent polarity. Even for DAAB and 4,4′-bis(diethylamino)azobenzene (BDEAAB), the rate is appreciably accelerated by external pressures in polar solvents. It is concluded that the observed results are more consistent with the inver...
TL;DR: In this paper, the incorporation of hydrophobic vitamin B12 derivatives into the single-compartment vesicles of N,N-didodecyl-Nα-[6-(tyimethylammonio)hexanoyl]-L-alaninamide bromide (N+C5Ala2C12) was found to be primarily concerned with the extent of insolubility of the cobalt complexes in the aqueous bulk phase, while such incorporation into single-walled VB12 derivatives was enhanced by the coordination interaction between the cob
Abstract: The incorporation of hydrophobic vitamin B12 derivatives into the single-compartment vesicles of N,N-didodecyl-Nα-[6-(tyimethylammonio)hexanoyl]-L-alaninamide bromide (N+C5Ala2C12) was found to be primarily concerned with the extent of insolubility of the cobalt complexes in the aqueous bulk phase, while such incorporation into the single-walled vesicles of N,N-ditetradecyl-Nα-[6-(trimethylammonio)hexanoyl]-L-histidinamide bromide (N+C5His2C14) was enhanced by the coordination interaction between the cobalt complex and the imidazolyl group of the lipid. In molecular aggregates formed with hexadecyltrimethylammonium bromide, α-[4-(1,1,3,3-tetramethylbutyl)phenyl]-ω-hydroxypoly(oxyethylene), or N+C5Ala2C12, the alkylation rates of a hydrophobic vitamin B12 with 1-bromo-2-methylpropane and methyl 2-methyl-3-bromopropanoate were much enhanced relative to those in methanol. In the N+C5Ala2C12 vesicle, a two-step mechanism was observed for the alkylation with the latter reagent. The possible origin of such rate...
TL;DR: In this paper, the authors derived theoretical equations for the mixed potential in the presence of interfering ions and the selectivity coefficients of the ion-selective electrodes can be expressed as a function of the difference between the standard ion-transfer potentials of the primary and interfering ions.
Abstract: The theory of liquid ion-exchange membrane ion-selective electrodes has been developed on the basis of the concept of the zero-current potential, or the mixed potential in the presence of interfering ions, of ion transfer at the interface between a liquid membrane and a sample solution. Under the assumptions of the reversible ion transfer at the interface, the presence of supporting electrolytes in both phases, and the monovalency of all relevant ions, theoretical equations for the mixed potential are derived for two cases; the primary and interfering ions have 1) the same charge sign and 2) the opposite sign. The selectivity coefficients of the ion-selective electrodes can be expressed as a function of the difference between the standard ion-transfer potentials of the primary and interfering ions, the ratios of the mass-transfer coefficients of the ions, and the ratios of the concentrations of the ions. The theoretical prediction has been shown to be applicable to an interpretation of the response of liq...
TL;DR: In this paper, conditions for the synthesis of a pure green rust II with a definite chemical composition and its transformation reaction to Fe3O4 under a nitrogen atmosphere were studied, and it was shown that green rust can be transformed to Fe 3O4 not only by oxidation but also spontaneously without oxidants.
Abstract: Conditions for the synthesis of a pure green rust II with a definite chemical composition and its transformation reaction to Fe3O4 under a nitrogen atmosphere were studied. A pure green rust II with the composition of (Fe3+)1(Fe2+)2(SO42−)(OH−)5−2n(O2−)n was obtained by the air oxidation of an aqueous solution containing (0.05 mol dm−3) FeII and (0.3 mol dm−3) SO42− ions at pH 6.8 and 25 °C. This iron composition differs from those estimated previously; therefore, the green rust II synthesized here is designated as green rust II(FeIII1–FeII2). This green rust II is spontaneously transformed into Fe3O4 under a nitrogen atmosphere at 50–75 °C. It has been accepted that green rust II is transformed to Fe3O4 by oxidation. The above evidence suggests that the green rust II can be transformed into Fe3O4 not only by oxidation but also spontaneously without oxidants.
TL;DR: In this paper, a homo-coupling of aryl, alkenyl, or heteroaromatic halides with zinc powder was demonstrated in NMP or HMPA solvent under mild conditions.
Abstract: Bis(trialkylphosphine)nickel(0) generated in situ from bis(trialkylphosphine)nickel(II) chloride was found to be an effective catalyst for a homo-coupling of aryl, alkenyl, or heteroaromatic halides with zinc powder. The catalytic reaction proceeded very well in NMP or HMPA solvent under mild conditions to afford dehalogenative-coupling products in good yields.
TL;DR: Grignard reagents reacted with 1-t-butyldimethylsilylpyridinium triflate with almost complete regioselectivity to afford the corresponding 1,4-dihydropyridines, which were easily oxidized by oxygen to give 4-substituted pyridine in higher yields than above.
Abstract: RCu·BF3 reacted with 1-ethoxycarbonylpyridinium chloride at the 4-position with almost complete regio-selectivity (>99%) to afford the corresponding 1,4-dihydropyridine derivatives in high yields (81–94%). The dihydropyridines were oxidized by oxygen to give 4-alkyl(aryl)pyridines (38–68%). Grignard reagents also reacted with 1-t-butyldimethylsilylpyridinium triflate with almost complete regioselectivity (>99%) to afford the corresponding 1,4-dihydropyridines, which were easily oxidized by oxygen to give 4-substituted pyridines in higher yields than above (58–70%).
TL;DR: In this paper, a study was carried out on the reaction of alkali metal carbonates with epihalohydrins in the presence of cation complexing agents e.g. crown ethers.
Abstract: A study has been carried out on the reaction of alkali metal carbonates with epihalohydrins in the presence of cation complexing agents e.g. crown ethers. 3-Glycidyloxypropylene carbonate was found to be formed as the main product of the reaction of epichlorohydrin with potassium carbonate promoted by 18-crown-6. The effect of various epihalohydrins and alkali metal carbonates on the reaction course was examined. It was found that the reaction of potassium hydrogencarbonate with epichlorohydrin gives 4-hydroxymethyl-1,3-dioxolan-2-one. When the reaction of epihalohydrins with potassium carbonates was carried out in the atmosphere of carbon dioxide the products contained linear carbonate linkage apart from cyclic one. From these results, a plausible mechanism was proposed for the reaction of alkali metal carbonates with epihalohydrins in the presence of crown ethers.
TL;DR: In this article, the first-order rate constants for proton transfer, ionic dissociation, and inter-system crossing crossing were derived for CAH· and D·.
Abstract: Mechanisms of hydrogen atom abstraction reactions by triplet state p-chloranil (3CA) from durene (DH) were studied by picosecond and nanosecond laser photolysis and transient photoconductivity measurements. 3CA was quenched by DH through diffusional encounter to form a triplet ion pair (IP) between CA and DH, p-chloranil semiquinone radical (CAH·), and 2,4,5-trimethylbenzyl radical (D·). Ionic dissociation of IP was observed in 1,2-dichloroethane (DCE) as well as in acetonitrile. However, no transient species was observed by direct excitation of a charge-transfer (CT) band of the electron donor-acceptor (EDA) complex between CA and DH. The H-atom transfer leading to production of CAH· was found to proceed through two distinct mechanisms; H-atom transfer via IP (Mechanism I) and a more rapid transfer competing with IP formation (Mechanism II). The quantum yields of CAH· produced by Mechanisms I and II and the first-order rate constants for proton transfer, ionic dissociation, and intersystem crossing compe...
TL;DR: In this paper, the title reaction in the presence of tetrakis(triphenylphosphine)palladium(0) affords alkylative coupling products in good to excellent yields in 1,2-dichloroethane at room temperature.
Abstract: The title reaction in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) affords alkylative coupling products in good to excellent yields in 1,2-dichloroethane at room temperature. This coupling reaction under C(sp2)–O cleavage proceeds stereospecifically. The reaction does not affect a coexisting vinyl sulfide group. This feature enables 1,2- and 1,3-carbonyl transposition with or without alkylation via phenylthio-substituted enol phosphates.
TL;DR: The solid-liquid phase diagrams of binary mixtures of tetrabutylammonium carboxylates, (n-C4H9)4 NOOCR with water were examined in order to confirm the formation of clathrate-like hydrates.
Abstract: The solid-liquid phase diagrams of binary mixtures of tetrabutylammonium carboxylates, (n-C4H9)4 NOOCR (R=H-n-C10H21 including various alkyl groups replaced by either methyl or ethyl group), with water were examined in order to confirm the formation of clathrate-like hydrates. The results can be summarized as follows: (1) for 14 carboxylates the formation of a clathrate-like hydrate is newly confirmed; (2) judging from melting points and hydration numbers, the hydrates can be classified into three groups: I, II, and III; (3) the group I hydrates, formed by the carboxylates with R=H, CH3, C2H5, n-C3H7, i-C3H7, and t-C4H9, have hydration numbers around 30 and are the most stable hydrates among those examined in this experiment, with the exceptions of 2-methylpropionate and 2,2-dimethylpropionate hydrates; (4) the group II hydrates, with hydration numbers around 39, are formed by the salts with R=n-C4H9, s-C4H9, i-C4H9, and all the C5H11, and are relatively unstable (mp=5–11 °C); (5) the group III hydrates, ...