Synthesis of bicyclic diesters of malonic and succinic acids

Monoesters of malonic and succinic acids have been prepared in high yields by the BF₃·OEt₂-catalyzed addition of the acids to bicyclo[2.2.1]hept-2-ene. The synthesized monoesters were introduced in the reaction of esterification with saturated monoatomic alcohols С₂–С₇ in the presence of the KU-2-8 catalyst in the H-form, and the corresponding mixed diesters of dicarboxylic acids were obtained in high yields.     

Novel Approach to the Synthesis of Phosphorus Sulfur Organic Compounds and Their Metal Complexes

Abstract

The reaction of elemental phosphorus (P_{ti 4}) and sulfur with protonodonor reagents (alcohols, phenols, and thiols) has been studied in the presence of amines and complexes based on trialkyltrithiophosphites and transition metal halides. A novel approach to the synthesis of phosphorus sulfur organic compounds has been proposed on the basis of these reactions.     

Freeze-out extraction of monocarboxylic acids from water into acetonitrile under the action of centrifugal forces

It is established that the efficiency of the freezing-out extraction of monocarboxylic acids С₃–С₈ and sorbic acid from water into acetonitrile increases under the action of centrifugal forces. The linear growth of the partition coefficient in the homologous series of С₂–С₈ acids with an increase in molecule length, and the difference between the efficiency of extracting sorbic and hexanoic acid, are discussed using a theoretical model proposed earlier and based on the adsorption–desorption equilibrium of the partition of dissolved organic compounds between the resulting surface of ice and the liquid phase of the extract. The advantages of the proposed technique with respect to the degree of concentration over the method of low-temperature liquid-liquid extraction are explained in light of the phase diagram for the water–acetonitrile mixture.     

α,ω-Bis(Dialkylthiophosphoryl)Sulfanes-Products of the Alcoholysis of Sulfur-Rich Phosphorus Sulfides

Abstract

The high solubility of sulfur-rich phosphorus sulfides in CS₂-especially in the range S:P=2.7 to 4-is the motive for new investigations on this system. DEMARCQ¹ suppsed the existence of “molecular products”, but he coulds not prove it by spectroscopic and chemical methods. As we have found the formation of α, ω-bis (fluorodithicphosphoryl) oliqosulfanes at the nucleophilic degradation of phosphorus sulfides with fluorides gives no proof for the existence of oligosulfane bridges in the sulfur-rich phosphorus sulfides. On the reaction of P₄S₁₀, elementary sulfur and alka-lifluorides the same products are formed. Sulfur-rich phosphorus sulfides and alcohols also react to mixtures of α,ω-bis (dialkylthiophosphoryl)sulfanes. But these compounds are not obtained by the reaction of P₄S₁₀ and sulfur with alcohols.     

Partial Oxidation of Alcohols to Aldehydes and Ketones Under Mild Conditions

Abstract

A number of aldehydes and ketones were prepared by partial oxidation of alcohols in air catalyzed by RuO₂/ZSM‐5 which can be easily prepared with the industrial grade ZSM‐5 and RuCl₃ · xH₂O.     

Synthesis of Tricyclic Diesters from 8-Acetoxytricyclodec-3-ene Monoester

Tricyclic diesters were synthesized in yields of 70.4–90.8% by the addition of С₂–С₅ monobasic carboxylic acids to tricyclo[5.2.1.0^2,6]dec-3-еn-8-yl acetate in the presence of a BF₃·OEt₂ catalyst. One of the synthesized diesters, tricyclodec-3,8-diyl diacetate, has a pleasant smell with a citrus scent and can be used in different perfume compositions as a flavoring.     

Catalytic conversion of aliphatic alcohols on carbon nanomaterials: The roles of structure and surface functional groups

Carbon nanomaterials with the structure of graphene and different compositions of the surface groups are used as catalysts for the conversion of С₂–С₄ aliphatic alcohols. The conversions of ethanol, propanol- 1, propanol-2, butanol-1, butanol-2, and tert-butanol on carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are investigated. Oxidized and nonoxidized multiwalled carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are synthesized. X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning and transmission electronic microscopies, Brunauer–Emmett–Teller method, derivatographic analyses, and the pulsed microcatalytic method are used to characterize comprehensively the prepared catalysts. It was established that all of the investigated carbon nanomaterials (with the exception of nondoped carbon nanoflakes) are bifunctional catalysts for the conversion of aliphatic alcohols, and promote dehydration reactions with the formation of olefins and dehydrogenation reactions with the formation of aldehydes or ketones. Nanoflakes doped with nitrogen are inert with respect to secondary alcohols and tert-butanol. The role of oxygen-containing and nitrogen-containing surface groups, and of the geometrical structure of the carbon matrix of graphene nanocarbon materials in the catalytic conversion of aliphatic alcohols, is revealed. Characteristics of the conversion of aliphatic alcohols that are associated with their structure are identified.     

Triphenylethanediol-Derived 2-Chloro-1,3,2- dioxaphospholane: Synthesis,Structure, and Reaction with Chiral Alcohols

The reaction of (S)-1,1,2-triphenylethanediol (3) with phosphorus trichloride leads to the diastereoselective formation of (S _C,R _P)-2-chloro-1,3,2-dioxaphospholane (2). Its configuration has been determined by single crystal X-ray diffraction. When reacted with racemic secondary alcohols, diastereomeric phosphites are obtained, which display substantial shift differences in the ³¹P NMR spectra. Thus, chlorodioxaphospholane 2 can serve as derivatizing reagent for chiral secondary alcohols permitting to determine their enantiomeric excess.     

Temperature dependences of saturated vapor pressure and the enthalpy of vaporization of <Emphasis Type="Italic">n</Emphasis>-pentyl esters of dicarboxylic acids

The saturated vapor pressures and enthalpies of vaporization of n-pentyl esters of linear С₂–С₆ dicarboxylic acids are determined by the transpiration method in the temperature range of 309.2–361.2 K. The dependences of enthalpies of vaporization on the number of carbon atoms in the molecule and on the retention indices have been determined. The predictive capabilities of the existing calculation schemes for estimation of enthalpy of vaporization of the studied compounds have been analyzed.     

A New Heptanuclear Tin Cluster Containing Sulfur and Oxygen in the Framework

Abstract

We have recently reported that new structural forms having the cube, (n-BuSn(O)O₂PPh₂)₄, and oxygen-capped, [(n-BuSn(OH)O₂PPh₂)₃O] [O₂PPh₂], formulations can be prepared by the reaction of n-butylstannonic acid with the corresponding diorganophosphinic acid. In new work exploring the effects of the bulky mesityl group bound to phosphorus, a cube formulation was also obtained. When n-butylstannonic acid was reacted with dicyclohexylphosphinic acid in the presence of nitric acid an oxygen-capped cluster having nitrate as the anion was obtained, demonstrating that the phosphinate anion is not required to stabilize the o-capped cation. In an attempt to generate similar structural forms, with sulfur replacing oxygen in the framework, the reaction of n-butylstannonic acid with diphenylphosphine oxide in the presence of elemental sulfur has been explored. From this reaction, a new structural form, containing seven hexacoordinate tin atoms and incorporating sulfur into the framework, [(n-BuSn(S)O₂PPh₂)₃O]₂Sn, was obtained in a mixture of products. A comparison of the crystal structures of the three compounds indicates that the new form has structural features in common with both the cube and the o-capped cluster.     

Preparation of complexes formed in the reaction between diironnanocarbonyl and tetraalkyl(phenyl)diphosphine disulfides,R2P(S)P(S)R2 (R=Et,n -Pr,n -Bu,Ph)

Fe₂(CO)₉ and R₂P(S)P(S)R₂ (R = Et, n-Pr, n-Bu, Ph) react to form two types of cluster complexes Fe₃(CO)₉(μ₃-S)₂ (1), Fe₂(CO)₆(μ-SPR₂)₂ (2A)–(2D), [2A, R = Et; 2B, R = n-Pr; 2C, R = n-Bu; 2D, R = Ph]. The complexes result from phosphorus–phosphorus bond scission; in the former sulfur abstraction has also occurred. The complexes have been characterized by elemental analyses, FT-IR and ³¹P-[¹H]-NMR spectroscopy and mass spectrometry.     

Biotechnology is storming the heights of petrochemistry

This brief review deals with the most important recent achievements of industrial biotechnology in its competition with petrochemistry: creation of the bioethanol industry; discovery of the fermentation of CO-containing gases, a new way of converting biomass into chemicals; carrying out the fermentation of С₅ and С₆ carbohydrates at similar rates; development of new methods of producing divinyl, isoprene, nylon, butanol, higher straight-chain alcohols, isopropanol, isobutanol, 1,4-butanediol, 2,3-butanediol, and succinic acid; progress in the culturing and processing of microalgae, an important source of glycerol and higher carboxylic acids.     

Unusual behavior of 3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one towards some phosphorus reagents: Synthesis of novel diethyl 2-phosphonochromone,diethyl 3-phosphonopyrone and 1,3,2-oxathiaphosphinines

The chemical reactivity of 3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one (1) towards some phosphorus reagents was studied. The enaminone 1 was cyclized into diethyl 2-phosphonochromone 2 via its treatment with diethyl phosphite in basic medium. However, its reaction with triethoxy phosphonoacetate gave the substituted pyrone phosphonate 3. In addition, two novel examples of 4-(dimethylamino)-6-(2-hydroxyphenyl)-2-sulfido-4H-1,3,2-oxathia-phosphinines 6 and 7 were obtained from treatment of enaminone 1 with O,O-diethyl dithiophosphoric acid and Lawesson’s reagent. When enaminone 1 was also treated with phosphorus decasulfide, it was turned into 4H-thiochromene-4-thione while its treatment with phosphorus tribromide, phosphorus oxychloride, or phenylphosphonic dichloride, 4H-4-oxo-chromene was isolated in all cases. The possible reaction mechanisms of the formation of these products were discussed. The structures of newly isolated products were established by elemental analysis and spectral tools.     

REACTION OF α-CHLOROTOLUENE WITH ELEMENTAL SULFUR IN LIQUID AMMONIA

Abstract

α-Chlorotoluene (1) reacts with elemental sulfur in liquid ammonia affording dibenzyl disulfide (2), dibenzyl trisulfide (3), dibenzyl tetrasulfide (4), dibenzyl pentasulfide (5) and benzylidene benzylimide (6) at a low temperature such as 20°C. This reaction is presumed to be initiated by the nucleophilic attack of ammonium thioaminohydroxylate, “H₂NS^-NH₄ ⁺,” or dithioaminohydroxylate, “H₂NSS^-NH₄,” formed upon treating elemental sulfur in liquid ammonia, on α-chlorotoluene (1). Benzylidene benzylimide (6) is presumed to be formed from benzylamine, which can be formed by treatment of α-chlorotoluene (1) with ammonia.     

OXYPHOSPHORANE MODELS FOR NUCLEOPHILIC DISPLACEMENTS AT Pα AND Pγ OF ADENOSINE-5′ TRIPHOSPHATE

Abstract

The reaction of dimethylphosphorous triethylpyrophosphoric anhydride, (CH₃O)₂POP(O)(OC₂H₅)OP(O)(OC₂H₅)₂, with hexafluorobiacetyl, CF₃COCOCF₃, yields 4,5-bis(trifluoromethyl)2,2-dimethoxy-2-triethylpyrophosphato-2,2-dihydro-1,3,2-dioxaphospholene. This oxyphosphorane, with a pyrophosphate group at the apical position of trigonal bipyramidal phosphorus, simulates the pentacovalent intermediate in the addition-elimination mechanism of nucleophilic displacements at the Px and Py centers of adenosine-5′ tri-phosphate. The oxyphosphorane is remarkably stable in solution, although the pyrophosphate group is easily displaced by an alkoxy group in base-catalyzed reactions with alcohols.     

Synthesis,X-ray characterization,and in vitro biological approach of dimeric and polymeric mercury(II) complexes with α-keto stabilized sulfur ylide

Abstract

Reaction of α-keto stabilized sulfur ylide (Me)₂SCHC(O)C₆H₄-p-CN (Y) with HgX₂ (X?=?Cl, Br, and I) led to the formation of new dinuclear products of the type [HgX₂(Y)]₂ (X?=?Cl (1), Br (2), and I (3)). Furthermore, the reaction of the corresponding sulfur ylide (Y) with Hg(NO₃)₂·H₂O in equimolar ratio, using methanol as a solvent, was shown to produce the polynuclear complex [(Y)Hg(NO₃)₂]_n (4). The obtained compounds were characterized using elemental analysis, IR, ¹H and ¹³C NMR techniques. The structures of compounds Y and 1 were characterized by single-crystal X-ray diffraction (XRD) analysis. Also, in order to confirm the crystalline nature of complexes 1–3, powder XRD pattern was used. Likewise, the antioxidant property of the complexes was examined by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging which revealed the strong-to-moderate radical scavenging ability (IC₅₀; 0.163?±?0.004 to 0.936?±?0.012?mg·mL^?1) of the synthesized compounds. Further, results from this study indicated that the compounds possess moderate antibacterial activity.     

Synthesis and Characterization of New N-(Diphenylphosphino)-Naphthylamine Chalcogenides: X-Ray Structures of (1-NHC10H7)P(Se)Ph2 and Ph2P(S)OP(S)Ph2

Abstract

The reaction of 1-naphthylamine with one equivalent of chlorodiphenylphosphine in the presence of triethylamine gave the (1-NHC₁₀H₇)PPh₂ (1) ligand. Refluxing of 1 with elemental sulfur or grey selenium in toluene (1:1 molar ratio) afforded (1-NHC₁₀H₇)P(S)Ph₂ (2) and (1-NHC₁₀H₇)P(Se)Ph₂ (3), respectively. Moreover, the byproduct {Ph₂P(S)}₂O (4) was isolated from the reaction of 1 with elemental sulfur. Compounds 1–3 were identified and characterized by multinuclear (¹H, ¹³C, ³¹P, ⁷⁷Se) NMR spectroscopy, mass spectrometry, and elemental analysis. Crystal structure determinations of 3 and 4 were carried out.     

Synthesis of β-(2,2-diethoxyethyl)-substituted (allyl)tributylstannane and its application to asymmetric allylation

Previously unknown tributyl-[(2-methylidene-4,4-diethoxy)butyl]stannane was prepared from diethyl acetal of 3-(bromomethyl)but-3-enal and was brought subsequently into a catalytic asymmetric Keck allylation of butanal in order to obtain optically active homoallylic alcohol. The use of activating additives [B(OBu)₃ and CF₃COOH] favors the process proceeding with high yields and enantioselectivity. An approach was suggested to the synthesis of С¹⁴–С²¹ fragments of amphidinolide Т applying tributyl[(2-methylidene-4,4-diethoxy)butyl]stannane in the key stage of building up the carbon scaffold.     

Synthesis,structure, and electrochemistry of mer[RuCl3(DMSO–S)(DMSO–O)(py)]

Reaction of mer-[RuCl₃(DMSO–S)₂(DMSO–O] (1) with pyridine (py) in dichloromethane yields mer-[RuCl₃(DMSO–S)(DMSO–O)(py)] (2). A single crystal suitable for X-ray diffraction was obtained by recrystalization with dichloromethane and diethyl ether. X-ray diffraction analysis revealed an unusual case in which two independent molecules (2a and 2b) are present in the asymmetric unit cell. Both molecules have distorted octahedral geometry in which DMSO is bound through oxygen and sulfur. Density functional theory (DFT) calculations were performed for 2a and 2b in gas phase to investigate bonding shown by the two DMSO ligands. Optimizations were done on both DMSO ligands bonded through S, both DMSO ligands bonded through O, one DMSO bonded through O, and the other through S but opposite to the actual molecule. The energy differences of the optimized structures were calculated.