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The direct amidation of carboxylic acids with N-substituted formamides has been accomplished via ruthenium catalysis. In the presence of ruthenium catalyst, a versatile range of carboxylic acids and N-substituted formamides undergoes amidation reaction to produce synthetically useful amides in good yields. C[dbnd]O in amide product came from benzoic acid but not N-substituted formamides, and which was confirmed by Isotope experiment.

Oxidative coupling of alcohols (methanol and ethanol) and dimethylamine on atomic-oxygen-activated Au(111) occurs entirely on the surface to form the corresponding amides when the alkoxy of the alcohol and the amide derived from the amine are co-adsorbed. For effective oxygen-assisted coupling the formation of the amide requires excess methanol. Mechanistic studies reveal that molecularly adsorbed methanol removes excess adsorbed atomic oxygen efficiently, precluding either secondary oxidation or oxidative dehydrogenation of dimethylamide to the imine. The adsorbed amide then can react with the aldehyde produced by β-hydride elimination from the alkoxy to form the hemiaminal, the reactive intermediate leading to coupling. The selectivity for formamide production can be increased to nearly 100 % in excess methanol. Copyright

This work describes a highly efficient unstrained C(sp3) - N bond activation approach for synthesis of N,N-dimethylacetamide (DMAc) via catalytic carbonylation of trimethylamine using a PdCl2/bipy (bipy = 2,2′-bipyridine)/Me4NI catalyst system. A low Pd catalyst dosage (1.0 mol%) is sufficient for high selectivity (98.1%) and yield (90.8%), with a turnover number (TON) of 90.0 mmol of DMAc obtained per mmol of PdCl 2 employed under mild reaction conditions. The influence of reaction parameters such as catalyst precursor dosage, ligand type and promoter on activity is investigated. This work also discusses in detail the halide promoter's role in the reaction, and provides a plausible mechanism based on the intermediates methyl iodide and acetyl iodide. Analyses indicate that the carbonylation of trimethylamine may proceed through an active intermediate acetyl iodide formed by carbonylation of methyl iodide generated from the decomposition of the promoter Me4NI under reaction conditions. The formation of acetyl iodide favors the cleaving efficiency of the inert unstrained C(sp3) - N bond of trimethylamine. Copyright

P-phenyl C-aminophosphaalkenes 1 react with p-chlorobenzonitrile oxides at -20°C leading to 1,2,4-oxazaphospholines 2, which are characterized by NMR and decompose slowly at room temperature. An experimental and theoretical study of their thermal evolution shows that the most probable mechanism involves the formation of an azaphospholine such as 10 which is unstable generating a phenyl phosphinidene. The latter polymerize quickly.

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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.

Herein, we report the synthesis of acetamides from CO2, methanol, H2 and corresponding amines, which is a new route used to synthesize acetamides. It was found that the Rh catalyst with LiI/LiCl as promoters could effectively catalyze this reaction. Interestingly, no ligand was required and amine substrates played a role in accelerating the reaction.

Second-order rate constants were determined in D2O for deprotonation of acetamide, N,N-dimethylacetamide, and acetate anion by deuterioxide ion and for deprotonation of acetamide by quinuclidine. The values of kB = 4.8 × 10-8 M-1 s-1 for deprotonation of acetamide by quinuclidine (pKBH = 11.5) and kBH = 2-5 × 109 M-1 s-1 for the encounter-limited reverse protonation of the enolate by protonated quinuclidine give pKac = 28.4 for ionization of acetamide as a carbon acid. The limiting value of kHOH = 1 × 1011 s-1 for protonation of the enolate of acetate anion by solvent water and kHO = 3.5 × 10-9 M-1 s-1 for deprotonation of acetate anion by HO- give pKac ≈ 33.5 for acetate anion. The change in the rate-limiting step from chemical proton transfer to solvent reorganization results in a downward break in the slope of the plot of log kHO against carbon acid pKa for deprotonation of a wide range of neutral α-carbonyl carbon acids by hydroxide ion, from -0.40 to -1.0. Good estimates are reported for the stabilization of the carbonyl group relative to the enol tautomer by electron donation from α-SEt, α-OMe, α-NH2, and (αO- substituents. The α-NH2 and α-OMe groups show similar stabilizing interactions with the carbonyl group, while the interaction of α-O- is only 3.4 kcal/mol more stabilizing than for α-OH. We propose that destabilization of the enolate intermediates of enzymatic reactions results in an increasing recruitment of metal ions by the enzyme to provide electrophilic catalysis of enolate formation.

The electroreduction of CO2 is a promising technology for carbon utilization. Although electrolysis of CO2 or CO2-derived CO can generate important industrial multicarbon feedstocks such as ethylene, ethanol, n-propanol and acetate, most efforts have been devoted to promoting C–C bond formation. Here, we demonstrate that C–N bonds can be formed through co-electrolysis of CO and NH3 with acetamide selectivity of nearly 40% at industrially relevant reaction rates. Full-solvent quantum mechanical calculations show that acetamide forms through nucleophilic addition of NH3 to a surface-bound ketene intermediate, a step that is in competition with OH– addition, which leads to acetate. The C–N formation mechanism was successfully extended to a series of amide products through amine nucleophilic attack on the ketene intermediate. This strategy enables us to form carbon–heteroatom bonds through the electroreduction of CO, expanding the scope of products available from CO2 reduction.

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An efficient continuous photochemical process is presented that delivers a series of novel γ-aminopropylsulfones via a tetrabutylammonium decatungstate (TBADT) catalysed HAT-process. Crucial to this success is the exploitation of a new high-power LED emitting at 365 nm that was found to be superior to an alternative medium-pressure Hg lamp. The resulting flow process enabled the scale-up of this transformation reaching throughputs of 20 mmol h-1 at substrate concentrations up to 500 mM. Additionally, the substrate scope of this transformation was evaluated demonstrating the straightforward incorporation of different amine substituents as well as alkyl appendages next to the sulfone moiety. It is anticipated that this methodology will allow for further exploitations of these underrepresented γ-aminopropylsulfone scaffolds in the future. This journal is

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The diethyl dithiocarbamate (DDC) collector, a precursor of toxic N-nitrosamines, is detected in flotation wastewaters usually at the ppm level. In this study, the O3 and O3/Vacuum-UV (O3/VUV) processes were compared to investigate the efficient removal of DDC with a low risk of N-nitrosamine formation. The results showed that 99.55% of DDC was removed at 20 min by O3/VUV, and the degradation rate constant was 3.99 times higher than that using O3-alone. The C, S and N mineralization extents of DDC using O3/VUV reached 36.36%, 62.69% and 79.76% at 90 min, respectively. O3/VUV achieved a much higher mineralization extent of DDC than O3-alone. After 90 min of degradation, O3/VUV achieved lower residual concentrations of CS2 and H2S, and released lower amounts of gaseous sulfur byproducts compared to O3-alone. The solid phase extraction and gas chromatography-mass spectrometry (SPE/GC-MS) analysis indicated that the main byproducts in O3/VUV degradation of DDC were amide compounds without the detection of N-nitrosamines. The avoidance of N-nitrosamine formation might be attributed to exposure of UV irradiation and enhanced formation of OH radicals in the O3/VUV system. The degradation pathways of DDC were proposed. This work indicated that O3/VUV was an efficient alternative treatment technique for the removal of DDC flotation collector with low risk of N-nitrosamine formation.

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Catalytic carbonylation of quaternary ammonium salts under anhydrous conditions was investigated using palladium catalyst. The carbonylation of tetramethylammonium iodide was chosen as a model reaction and studied systematically. Ligand-free PdCl2 showed efficient catalytic performance for this transformation. A palladium catalyst loading as low as 0.05 mol% was sufficient for high yield (96.9%) of N,N-dimethylacetamide, corresponding to a turnover frequency of 242 h-1. Under optimum conditions, several other quaternary ammonium halides were also carbonylated to corresponding tertiary amides in moderate to excellent yields. The catalytic activity of commercial palladium on activated carbon (Pd/C) catalyst was also evaluated. The Pd/C catalyst exhibited high activity for this carbonylation reaction and could be recycled six times with a slight decrease in activity. Furthermore, mechanistic considerations concerning Pd-catalyzed carbonylation of quaternary ammonium halides were also discussed. Copyright

A quantitative Lewis acidity/basicity scale toward boron-centered Lewis acids has been developed based on a set of 90 experimental equilibrium constants for the reactions of triarylboranes with various O-, N-, S-, and P-centered Lewis bases in dichloromethane at 20 °C. Analysis with the linear free energy relationship log KB=LAB+LBB allows equilibrium constants, KB, to be calculated for any type of borane/Lewis base combination through the sum of two descriptors, one for Lewis acidity (LAB) and one for Lewis basicity (LBB). The resulting Lewis acidity/basicity scale is independent of fixed reference acids/bases and valid for various types of trivalent boron-centered Lewis acids. It is demonstrated that the newly developed Lewis acidity/basicity scale is easily extendable through linear relationships with quantum-chemically calculated or common physical–organic descriptors and known thermodynamic data (ΔH (Formula presented.)). Furthermore, this experimental platform can be utilized for the rational development of borane-catalyzed reactions.

PROBLEM TO BE SOLVED: To provide a production method with which N,N-dimethylamide can be produced by making a nitrile and methanol react with each other in gas phase. SOLUTION: A production method of N,N-dimethylamide for producing N,N-dimethylamide by making a nitrile and methanol react with each other in gas phase in the presence of a catalyst is disclosed, in which the nitrile is acetonitrile or propionitrile and the catalyst is an alloy containing copper and aluminum. Preferably acetonitrile is used as the nitrile. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT

To provide a method for producing an N, N-disubstituted amide in which an N,N-disubstituted amide can be obtained by a reaction of a nitrile and an alcohol even by a liquid phase reaction and a gas phase reaction and the object product obtained after the reaction and a catalyst can be easily separated.SOLUTION: There is provided a method for producing an N,N-disubstituted amide by reacting a nitrile and an alcohol in the presence of a catalyst, wherein the catalyst is a heterogeneous catalyst composed of a carrier and a metal oxide carried on the carrier, the carrier is at least one selected from zeolite, silica and alumina and a metal included in the metal oxide includes at least one selected from copper and molybdenum.SELECTED DRAWING: None

Acyl nitroso compounds or nitrosocarhonyls (RC(O)N=O) are reactive short-lived electrophiles, and their hydrolysis and reactions with nucleophiles produce HNO. Previously, direct detection of acyl nitroso species in nonaqueous media has been provided by time-resolved infrared spectroscopy demonstrating that its half-life is about 1 ms. In the present study hydroxamic acids (RC(O)NHOH) are oxidized electrochemically in buffered aqueous solutions (pH 5.9-10.2) yielding transient species characterized by their maximal absorption at 314-330 nm. These transient species decompose via a first-order reaction yielding mainly HNO and the respective carboxylic acid and therefore are ascribed to RC(O)N=O. The sufficiently long half-life of RC(O)N=O in aqueous solution allows for the first time the study of the kinetics of its reactions with various nucleophiles demonstrating that the nucleophilic reactivity follows the order thiolate > hydroxamate > amine. Metal chelates of CH3C(O)NHOH catalyze the hydrolysis of CH3C(O)N=O at the efficacy order of CuII > ZnII > NiII > CoII where only CuII catalyzes the hydrolysis also in the absence of the hydroxamate. Finally, oxidation of hydroxamic acids generates HNO, and the rate of this process is determined by the half-life of the respective acyl nitroso compound.

The invention discloses a process for synthesizing N,N-dimethylacetamide. The N,N-dimethylacetamide is prepared through operation means of ultrasonic oscillation, magnetic stirring and infrared treatment of the raw materials such as dimethylamine, acetylchloride, a home-made zirconium-modified nanoscale solid alkali catalyst.

Through the interception of amide ylides with sulfonamides, we herein report the first general example of an intermolecular condensation reaction between sulfonamides and amides. Beyond formamides, this approach was successfully applied to a variety of lactams and linear amides, giving rise to a broad array of (E)-N-sulfonyl amidines.

The selective oxidative coupling of aromatic carboxylic acids with the C(sp3)-H bond adjacent to the keto group of alkylamides has been developed by employing a low cost copper source. This provides an efficient approach for synthesis of O-benzoylglycolamides. The protocol displayed good functional group tolerance. A broad range of benzoic acids directly coupled with alkylamides to afford a variety of O-benzoylglycolamides in moderate to good yields. In addition, a reasonable radical mechanism was proposed based on EPR experiments.

A method for preparing methallyl alcohol and amide simultaneously is characterized in that methylallyl carboxylate taken as a raw material and an amine compound taken as an ammonolysis agent react under the action of a catalyst to produce methallyl alcohol and an amide compound. The methylallyl carboxylate and the amine compound taken as the ammonolysis agent are firstly adopted, and the methallyl alcohol and the amide compound are obtained under the action of the catalyst. The reaction process is a bulk reaction, no solvents are added, almost no wastewater or salt are produced, and byproduct methyl allyl ether is not produced; the defect that a large number of wastewater is produced through hydrolysis is overcome due to adoption of ammonolysis, the methallyl alcohol and the amide compound are coproduced directly by use of ammonoysis, coupling production is realized, and the cost is reduced.

Ph3SiSH transforms amides to thioamides and Ph3SnOH performs the reverse process, with the concomitant formation of Ph3SiOH (or Ph3SiOSiPh3) and Ph3SnSSnPh3, respectively. The chemistry is a delightful illustration of the oxophilicity of silicon compared to the thiophilicity of tin and occurs under relatively mild conditions, and for amide to thioamide transformation requires no amide activation. The chemistry is in accord with available data for Si?(S)(O), Sn?(O)(S) and C?(O)(S) bond energies. Copyright

In the presence of phosphovanadomolybdic acids, e.g., H6PV3Mo9O40, desulfurization-oxygenation of various kinds of structurally diverse secondary and tertiary thioamides proceeded efficiently using molecular oxygen as the terminal oxidant, affording the corresponding amides in moderate to excellent yields. In addition, 18O-labeled amides could readily be synthesized using H218O as the oxygen source.

A series of acyl phosphonamidates, the synthetic precursors to bisphosphonates, have been readily prepared from phosphoramidite type reagents and a range of acid chlorides. These reactions were performed using solventless conditions, where purification was easily achieved using column chromatography with yields ranging from 71-90%. Furthermore, we have demonstrated that these acyl phosphonamidates could be used for the preparation of unsymmetrical bisphosphonates, which do date are scarcely reported in the literature.

An unsupported nanoporous gold catalyst is employed for the direct coupling of primary alcohols and amines to the corresponding amides in the liquid phase. Among others, the reaction of methanol and dimethylamine to the industrially relevant dimethylformamide proceeds smoothly at 40°C (turnover frequency≈40 h-1). The activation of molecular oxygen is identified as a key parameter. Doping of the unsupported catalyst by an admetal (Ru, Ag) is used to increase the activity of the catalyst considerably for this reaction (turnover frequency ≈ 100 h-1).

We reported here the catalytic carbonylation of quaternary ammonium salts under anhydrous condition. Quaternary ammonium salts, a kind of versatile reagents that were widely used in organometallic chemistry, can be carbonylated to tertiary amides by an in situ prepared NaCo(CO)4 catalyst. It was found that the counterions (Cl-, Br-, I-, OTf-) in the quaternary ammonium salts played a significant role in the reaction and tetramethylammonium iodide could give high yield (96%) of N,N-dimethylacetamide (DMAc) with only 0.5 mol% cobalt catalyst. Under optimum conditions, several other quaternary ammonium iodides were also carbonylated to corresponding tertiary amides in moderate to excellent yields. Obviously, these results also give us a special apprehension that Me4NI and other quaternary ammonium salts could be possibly carbonylated to tertiary amides in the carbonylation reaction where they are used as promoters or solvents in most cases. Considering the high activity and moderate to excellent selectivity, this process could be a potential method for the synthesis of certain tertiary amides. Moreover, the cleaving mechanism of CN bonds and the possible catalytic intermediates were discussed in detail.

An original one-pot synthesis of bromomethyl ketones is achived using the Petasis reagent (dimethyltitanocene) as a key for enamine generation. Several amides were used to test the limits of the procedure by changing either the alkyl chain R or the amino portion of the starting materials. The enamines generated in situ were allowed to react with bromine at low temperature followed by hydrolysis to yield bromomethyl ketones in excellent yields (85 to 95%). Mechanistic details and optimum conditions for the reaction are briefly discussed. The present approach offers several advantages such as regioselectivity in enamine formation, good yields, mild reaction conditions, and ease of experimentation.

Nanoporous metal oxide materials are ubiquitous in the material sciences because of their numerous potential applications in various areas, including adsorption, catalysis, energy conversion and storage, optoelectronics, and drug delivery. While synthetic

The invention relates to a continuous method for producing amides, according to which at least one carboxylic acid of formula (I) R3—COON ??(I) wherein R3 is hydrogen or an optionally substituted alkyl group comprising between 1 and 4 carbon atoms, is reacted with at least one amine of formula (II) HNR1R2 ??(II) wherein R1 and R2 are independently hydrogen or a hydrocarbon group comprising between 1 and 100 C atoms, to form an ammonium salt, and said ammonium salt is then reacted to form a carboxylic acid amide, under microwave irradiation in a reaction pipe, the longitudinal axis of the pipe being oriented in the direction of propagation of the microwaves of a monomode microwave applicator.

The present invention relates to a process for preparing secondary amides with good selectivity by carbonylating a corresponding tertiary amine with carbon monoxide in a reaction mixture in the presence of a metal catalyst and in the presence of a halogen containing promoter. The metal catalyst comprises palladium. A same or even a much better catalytic activity can be obtained with palladium than with the much more expensive rhodium, especially when the palladium is used in a low concentration. Moreover, also a good selectivity can be achieved.

Acyl iodides RCOI (R = Me, Ph) reacted with N,N-dimethylformamide and N,N-dimethylacetamide Me2NC(=O)R' (R' = H, Me) along two concurrent pathways involving transacylation and cleavage of the Me-N bond. The first pathway leads to the formation of acyl group exchange products, and the second, to the corresponding imides R'CON(Me)COR.

Acyl iodides reacted with excess primary and secondary amines in a way similar to acyl chlorides, yielding the corresponding carboxylic acid amide and initial amine hydroiodide. Reactions of tertiary amines with acyl iodides were accompanied by cleavage of the N-C bond with formation of the corresponding N,N-di(hydrocarbyl)carboxamide and alkyl iodide. In the presence of excess tertiary amine the latter was converted into quaternary tetra(hydrocarbyl) ammonium iodide.

The synthesis of the perdeuterated cellulose solvents NMMO-d11 (9) and N,N-dimethylacetamide-d9 (14) is described. NMMO-d 11 was obtained according to a five-step approach from non-labeled diglycolic acid (1) via diethylene glycole-d8 (4) and its bis-tosylate (5), which underwent cyclization with benzylamine to N-benzylmorpholine (6). The removal of the benzyl protecting group, methylation and N-oxidation completed the synthesis. DMAc-d9 (14) was obtained from deuterated acetic acid (10) and dimethylamine-carbon dioxide complex (17) with acidic alumina as the catalyst according to a solvent-free gas-solid reaction. Copyright

The invention relates to a method for producing N,N-dimethylacetamide (DMAC) by the continuous reaction of methyl acetate (MeOAc) with dimethyl amine (DMA) in the presence of an alkaline catalyst. Said method is characterised in that the MeOAc is in the form of a methanolic solution and that between 0.0002 and 0.09 mol catalyst per mol MeOAc is used. The reaction is carried out at a temperature ranging between 90 and 140 °C and at an absolute pressure ranging between 10 and 30 bar.

A method for the production of N,N-dimethylacetamide (DMAC) by continuous reaction of methylacetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, wherein MeOAc is used as a methanolic solution and continuous distillatory preparation is carried out in such a way that initially methanol and optionally other low boiling substances are separated at the head of a column A and the yield from the bottom of column A is fed to column B, wherein DMAC having a purity of ≥ 99.7 % by weight is separated via a lateral outlet.

Disclosed is a method for producing N,N-dimethylacetamide (DMAC) by continuously reacting methyl acetate (MeOAc) with dimethylamine (DMA) in the presence of a basic catalyst, MeOAc being used as a methanol solution which is obtained as a byproduct during the production of polyTHF by transesterifying polyTHF diacetate with methanol.

An efficient procedure is proposed for the synthesis of 1,3-dialkylimidazolium salts starting from 1,4-diaza-1,3-dienes and methyleneammonium salts.

(Pyridine)(tetrahydroborato)zinc complex, (Py)Zn(BH4)Z, can efficiently perform acetylation of a variety of aliphatic and aromatic amines with ethyl acetate under refluxing THF.

The invention disclose a hydrogen fluoride containing composition comprising hydrogen fluoride and a compound which is liquid in the standard state (25° C., 1 atmosphere) and has a boiling point of 120° C. or more and pka of 12 or more at 25° C., and use of the composition for a fluorination agent. The compound which can be preferably used is represented by the formula (1): wherein R1 to R4 are a substituted or unsubstituted alkyl or aryl group and can be the same or different, and R1 or R2 or R3 and R4 can bond to form a ring having a nitrogen atom or a nitrogen atom and other hetero atom, or R1 and R3 can bond to form a ring having a nitrogen atom or a nitrogen atom and other hetero atom. The fluorination agent of the invention exerts effect with a similar reaction mechanism to hydrogen fluoride, can be applied to the halogen exchange reaction of a halogen containing organic compound, and can produce a fluorine containing compound with safety and ease without specific equipment or technique.

The oxidation of 1,2-amino alcohols and α-amino ketones can be efficiently performed using potassium hydroxide in the presence of air. This novel procedure affords carboxylic derivatives in excellent yields and high purity.

Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels. Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels.

New C4v tetraoxatetrathiahemicarcerands and their six hemicarceplexes containing DMF, DMA, DMSO, or NMP were synthesized and characterized. Their conformations, kinetic properties, carceroisomerism, and twistomerism were studied by VT, 2D COSY, NOESY, and ROESY 1H NMR experiments. The decomplexation rates of DMF or DMA were very slow with high activation energy barriers (73 and 104 kJ mol-1, respectively) and the complexed guests feel more constriction than their free liquid state. The largest isomerization energy barrier of carceroisomers was 15.4 kcal mol-1, and the isomerization energy barriers of twistomers are significantly larger than those of carceroisomers.

The azavinylogous aminalester 3 reacts with primary amines to give amidines 5 and 6. In the reaction of 3 with aniline the azavinylogous amidine 7 is produced additionally to the amidine 5c. Ethylendiamine is formylated at both aminogroups, the bis-amidine 8 thus formed is transformed to the salts 9a,b. Benzoxazole and benzimidazole can be prepared from 3 and o-aminophenol and o-phenylenediamine, resp. Carboxylic acid amides, urea, thiourea, aromatic acid hydrazides 17 and the sulfonylhydrazide 19 are formylated by 3 at nitrogen to give N-acylated formamidines 14, 16, 18, 20. From 3 and aliphatic acid hydrazides 17 and alkylhydrazines, resp., can be obtained 1,2,4-triazole 21 and 1-alkyl-1,2,4-triazoles 22a,b, resp. N.N-Dimethylcyanacetamide (32) reacts with 3 and the orthoamide 4a, resp., to give a mixture of the formylated compound 34 and the amidine 33. The reaction conditions are of low influence on the ratio in which 33 and 34 are formed. The orthoamide 4b and 32 react to afford a mixture of the amidine 35 and the enamine 36. Hydrogen-sulfide acts on 3 giving N,N-dimethylthioformamide (37). From 3 and 1-alkynes 41 can be prepared the amidines 42. Hydrolysis of 42b affords phenylpropiolaldehyde (43). The alkylation of the aminalester 3 gives rise to the formation of vinylogous amidinium salts 1c and 1d, resp., additionally is formed the amide acetal 2a. The salt 1d can also be prepared from 3 and borontrifluoride-ether. Iodide reacts with N,N-dimethylformamide acetals 12a,b in an unclear, complicated manner giving orthoesters 53, N,N-dimethylformamide, alkyliodides, alcohols, ammonium iodides 46 and carbondioxide. The action of halogens on 3 affords the salts 1a,b,c,e,f depending on the chosen stoichiometric ratio. Aromatic aldehydes are suited for trapping azavinylogous carbenes formed on thermolysis of 3; 1,3-oxazoles 69 are the reaction products. From 3 and propionaldehyde the amidine 65 can be obtained with low yield. Carbondisulfide transforms 3 to the azavinylogous salt 66. The preparation of the azavinylogous orthoamide 4a is described. The thermolysis of 3 and 4a, resp., gives rise to the formation of the triaminopyrimidine 67. Treatment of 1a with lithium diisopropylamide affords the triaminopyrazine 68, which can also be obtained by thermolysis of 3 in the presence of sodium hydride. Azavinylogous carbenes are thought to be the intermediates. Wiley-VCH Verlag GmbH, 2000.

N,N-Disubstituted 2-aminooxazoles react with maleimide in two directions: heterodiene synthesis with the formation of imides of 2-aminopyridine-3,4-dicarboxylic acids and/or 1,3-cycloaddition, forming imides of 2-amino-5-acyl-Δ1-pyrrolidine-3,4-dicarboxylic acids.

Two D4h container hosts 12 and 13 with 4(CH2-O-bridge-O-CH2) portal pillars were obtained in good yields by stepwise synthetic routes and showed complementary complexation behaviors to their analogues with (O-CH2-bridge-CH2-O)4 portal pillars. 1H NMR spectral chemical shifts of host's inward-turned OCH2O protons were sensitive to guest change. The stability orders of hemicarceplexes were 12-p-(CH3CH2)2C6H4 > 12-p-(CH3O)2C6-H4 ? 12-o-(CH3O)2C6H4 > 12-m-(CH3O)2C6H4 and 13-CH3COCH2CH3 > 13-CH3COCH2CH(CH3)2 > 13-CH3-CON(CH3)2 > 13-CH3COOCH2CH3 > 13-CH3CH2CON(CH3)2 in terms of the activation energy barrier for decomplexation. Large solvent effects on the activation energy for decomplexation of hemicarceplexes were observed.

An object of the present invention is to provide a novel bisbenzotriazolylphenol compound having a UV absorving effect. The bisbenzotriazolylphenol compound of the invention is represented by the formula STR1 wherein A is a direct bond or represents a C1-6 alkylene group, a --C(CH3)2 -- group, a --C(C2 H5)(CH3)-- group, a --O-- group or a --NH-- group, R1 and R3 are the same or different and each represent a hydrogen atom, a C1-4 alkyl group, an aryl group, a C1-4 alkoxy group or a halogen atom, and R2 and R4 are the same or different and each represent a hydroxyl group or a C1-12 straight- or branched-chain hydroxyalkyl group.

With electrospray (ES), ions present in solution can be transferred to the gas phase. The method provides unique opportunities for studies of hitherto inaccessible ions. Collision-induced dissociation threshold measurements of gas phase ions produced by ES are described. The thresholds for the reactions M+L = M+ + L, where M+ is Na+ or K+ and L is acetone, dimethyl sulfoxide, acetamide, N-methylacetamide, N,N-dimethylacetamide, glycine, glycinamide, succinamide, and glycylglycine, were determined. Enthalpy changes for the reaction were derived from these data.

Two new hemicarcerands (1 and 2) are reported, the former of which was induced to form 30 capsular complexes stable enough at 25 °C in CDCl3 to be isolated and characterized. The compounds are globe-shaped and composed by attaching two tetraaryl bowls to one another at their rims through four O(CH2)4O groups. To impart desired solubility properties to the final host, four C6H5CH2CH2 groups are attached to each bowl at their bases in 1, and four CH3(CH2)4 groups to each in 2. The shell closure, 2 Ar(OH)4 + 4 TsO(CH2)4OTs → Ar[O(CH2)4O]4Ar, conducted in (CH3)2NCOCH3-Cs2CO3 at 70 °C, gave 1·(CH3)2NCOCH3 (30-40%), and the same type of reaction in (CH3)2SO-Cs2CO3 gave 2·(CH3)2SO (15-20%), a molecule of solvent being incarcerated in each case. Empty 1 was obtained by heating 1·(CH3)2NCOCH3 in (C6H5)2O (molecules too large to be incarcerated) at 195 °C for 5 days (94%). Neat CH2Cl2 went in and out of the interior of 1 fast enough at 25 °C to be useful as solvent in chromatography of 1 and its complexes. By heating empty 1 at 70-170 °C for several hours up to 6 days in solutions of potential guests as solvent, or with 100 equiv of guest in (C6H5)2O as solvent, 30 hemicarceplexes were formed, isolated, purified, and characterized. In the crystal structure of 1·6H2O·4o-(CH3)2C6H4, the northern and southern hemispheres were twisted relative to one another around their polar axis by ~13°. The crystal structures of 1·p- l2C6H4·2C6H5NO2, 1·p-(CH3)2C6H4·2NO2C6H5, 1·O2NC6H5·2C6H5NO2, 1·o-BrC6H4OH·2C6H5NO2, and 1·(CH3)2NCOCH3·2C6H5NO2 were untwisted and belonged to the same space group. The lengths along the polar axes decreased in the order listed through conformational changes in the O(CH2)4O bridges. The E(a) for decomplexation of 1·(CH3)2NCOCH3 in C6D5NO2 at 140-170 °C (four temperatures) was 23.5 kcal mol-1. The rotations relative to their shells of large incarcerated guests, such as 2,4-Cl2C6H3CH3, 3,4-Cl2C6H3CH3, and 4- CH3C6H4OCH3, were slow enough on the 1H NMR time scale at 25 °C to produce different chemical shifts for the same host protons located in the northern and southern hemispheres of the complex. The smallest guest incorporated in 1 was Xe, but 1·Xe as a solid gave up its guest over days at ambient temperature.

Tris(dialkylamino)selenonium halides are formed in the reaction of N-trimethylsilyldialkylamines with the corresponding selenium tetrahalides.Tris(dialkylamino)selenonium chlorides react under mild conditions with carboxylic acids and their halides, phosphorus trichloride, and fluorosulfuranes to give amides, tris(dialkylamino)chlorophosphonium chlorides, and tris(dialkylamino)sulfonium pentafluoroselenates.

Gas phase basicities of α-trimethylsilylstyrenes have been determined by measuring proton transfer equilibrium constants.Basicity of α-trimethylsilylstyrene was found to be comparable to that of α-alkylstyrene, suggesting that α-trimethylsilyl group as well as α-alkyl group stabilizes a carbenium ion.

Treatment of Ru(COEt)Cl(CO)(PPh3)2 (1) with secondary amines (R2NH) under pressure of CO and/or ethylene gives propionyl-carbamoyl complexes Ru(COEt)(CONR2)(CO)(PPh3)2 (NR2 = NEt2 (4a), N(CH2)4CH2 (4b), NMe2 (4c)) together with the ammonium salt R2NH2Cl.Complexes 4a-c have been isolated as pale yellow crystals and characterized by means of NMR and IR spectroscopy and elemental analysis.Reactions of Fe(COMe)I(CO)2(PMe3)2 and BF4 with nucleophiles (HNEt2, LiNMe2, EtOH (in conjunction with Et3N) and NaOMe) give the corresponding acetamides and acetic acid esters.

Substitution of the dimethylamino group by chlorine in a series of P=O and P=S P(IV)-acid dimethylamides by means of acetyl chloride proceeds more readily for P=O amides.