Difunctional Group Research Articles

Preparation of propylene carbonate catalyzed by ionic liquid

The ionic liquid chlorination (1-amino-2-propyl alcohol)-3-buthylimidazole containing amino and hydroxy from the difunctional group is newly synthesized, the characterization of which is analyzed with NMR. It can catalyze CO2 and propylene oxide (PO) under certain conditions for preparation of propylene carbonate, with the conversion of 80.1% and the selectivity of 92.5%, which has superior performance to that of monoamino ionic liquid. The density functional theory and the quantum theory of atoms in molecules are adopted to theoretically analyze the stable structure and interactive relationship. According to the results of quantum chemical calculation, it is concluded that the functional groups of amino and hydroxy on IL are coupled with PO to generate hydrogen bond, based on which the mechanism of cycloaddition reaction can be inferred.

Hydrogen-bonding-assisted redox-neutral construction of tetrahydroquinolines via hydride transfer.

The hydrogen-bonding-assisted construction of tetrahydroquinolines decorated with structurally diverse 3,3'-difunctional groups has been realized via a hydride transfer-involved three-step cascade reaction in the presence of morpholine. This protocol solves the limitation of acyclic 1,3-dicarbonyl compounds by one-pot synthesis of tetrahydroquinolines, featuring operational simplicity, broadly applicable substrates, and metal- and acid-free conditions with EtOH as a hydrogen-bonding donor.

Synthesis and Polymerization of N,N'-[Bis(4,4'-Hydroxypropyl Methacrylate Phenylester) Pyromellitimide] Thermoset Polymer by Microwave Irradiation

A new difunctional monomer N,N'-[bis(4,4'-hydroxypropyl methacrylate phenyl ester) pyromellitimide] (BHPMEPM), was synthesized by the reaction of the bis(4-carboxyphenyl)-N,N'-pyromelli- timide acid (diacid-diimide), and two molar equivalents of glycidylmethacrylate (GMA). The reaction was carried out by microwave radiation. The presence of difunctional groups, double bond groups, makes the monomer a potential material for obtaining thermosetting product. The curing and thermal stability of the crosslinked products were studied by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) techniques. The difunctional monomer and its thermoset polymer were characterized by FT-IR, 1H-FT-NMR and CHN elemental analysis.

Stereoselective Synthesis of (1Z,3E)-2-Ethoxycarbonyl-Substituted 1,3-Dienes via Stille Coupling of (E)-α-Stannyl-α,β-Unsaturated Esters with Alkenyl Halides

Palladium-catalyzed hydrostannylation of alkynyl esters in benzene at room temperature gives stereoselectively (E)-α-stannyl-α,β-unsaturated esters 1 in good yields. (E)-α-Stannyl-α,β-unsaturated esters 1 are difunctional group reagents that undergo Stille coupling reactions with alkenyl halides 2 in the presence of Pd(PPh3)4 and CuI co-catalyst to afford stereoselectively (1Z,3E)-2-ethoxycarbonyl-substituted 1,3-dienes 3 in good yields.

A facile stereoselective synthesis of ( Z)-α-arylsulfonyl-α,β-unsaturated ketones

Palladium-catalyzed hydrostannylation of acetylenic sulfones 1 in benzene at room temperature gives highly regio- and stereoselectively ( E)-α-stannylvinyl sulfones 2 in high yields. ( E)-α-Stannylvinyl sulfones 2 are new difunctional group reagents which undergo Stille coupling reactions with acyl chlorides 3 to afford stereoselectively ( Z)-α-arylsulfonyl-α,β-unsaturated ketones 4 in good yields. A one-pot stereoselective synthesis of ( Z)-α-arylsulfonyl-α,β-unsaturated ketones 4 has also been achieved by tandem hydrostannylation-Stille coupling reaction of acetylenic sulfones 1 under mild conditions.

A Facile Stereoselective Synthesis of (Z)-2-ethoxycarbonyl-substituted 1,3-enynes from (E)-α-stannyl-α,β-unsaturated esters and alkynyl bromides

Palladium-catalysed hydrostannylation of alkynyl esters in benzene at room temperature gives regio- and stereoselectively ( E)-α-stannyl-α,β-unsaturated esters in good yields. ( E)-α-Stannyl-α,β-unsaturated ethyl esters are difunctional group reagents which undergo Stille coupling reactions with alkynyl bromides in the presence of Pd(PPh3)4 and Cul co-catalyst to afford stereoselectively ( Z)-2-ethoxycarbonyl-substituted 1,3-enynes in good yields.

Stereoselective Synthesis of Vinyl Sulfones by the Stille Coupling of (E)-α-Stannylvinyl Sulfones with Aryl Halides

Palladium-catalysed hydrostannylation of acetylenic sulfones (R–C≡C–SO2Ar) in benzene at room temperature gives stereoselectively (E)-α-stannylvinyl sulfones in good to high yields. (E)-α-Stannylvinyl sulfones are difunctional group reagents which undergo Stille coupling reaction with aryl halides in the presence of Pd(PPh3)4 and CuI co-catalyst to afford stereoselectively (Z)-1,2-disubstituted vinyl sulfones in good yields.

Preparation, fabrication and response behavior of a HTBN/TDI/MWCNT composite sensing film by in situ dispersed polymerization

A polyurethane inserted multi-wall carbon nanotube (MWCNT) composite conductive film was prepared by in situ dispersed polymerization reaction using hydroxyl-terminated poly(butadiene-acrylonitrile) liquid rubber as a linear diol, toluene diisocynate as a curative, ethylene glycol or glycerine or triethanolamine as a chain-extending agent and MWCNT as a conducive filler. The effect of various curing temperatures and chain-extending agents on vapor-induced electrical responsiveness of the conductive films was investigated. The structural characterization of the cured film was conducted by Fourier transformation infrared spectrophotometer (FTIR), differential scanning calorimeter (DSC), polarization microscope (POM) and wide angle X-ray diffraction (WAXD). The experimental results showed that the conductive composite film obtained in the present work exhibited a microphase separation resulting from the soft-hard segment domains, and possessed some crystalline behavior from the hard segment. The response intensity was enhanced with the curing temperature increased, while the reversibility could be improved at a relatively low curing temperature. The responsivity of the film produced by a linear difunctional group chain-extending agent was lower than that prepared by trifunctional group curatives, and the reversibility was vice versa. The experimental phenomena were explained from the viewpoint of the microphase separation, crystalline behavior, the structural characteristics of the soft-hard segment, and the electronic properties of multi-wall carbon nanotubes as well as a weak electrostatic or noncovalent interaction between polymer or analyte molecules and MWCNTs.

A Facile Stereoselective Synthesis of (Z)-2-arylsulfonyl-substituted 1,3-enynes from (E)-α-stannylvinyl Sulfones and Alkynyl Bromides

Palladium-catalysed hydrostannylation of acetylenic sulfones 1 in benzene at room temperature gives stereoselectively (E)-α-stannylvinyl sulfones 2 in good to high yields. (E)-α-Stannylvinyl sulfones 2 are difunctional group reagents which undergo cross-coupling reactions with alkynyl bromides 3 in the presence of Pd(PPh3)4 and CuI co-catalyst to afford stereoselectively (Z)-2-arylsulfonyl-substituted 1,3-enynes 4 in good yields.

A facile stereoselective synthesis of 1,3-dienyl sulfones via Stille coupling reactions of ( E)-α-stannylvinyl sulfones with alkenyl iodides

Palladium-catalyzed hydrostannylation of acetylenic sulfones 1 in benzene at room temperature gives stereoselectively ( E)-α-stannylvinyl sulfones 2 in good yields. ( E)-α-Stannylvinyl sulfones 2 are new difunctional group reagents which undergo Stille coupling reactions with alkenyl iodides 3 to afford stereoselectively 1,3-dienyl sulfones 4 in high yields.

Surface-active fluorocarbon end-functionalized polylactides

The synthesis and surface properties of a 2 × C 8F 17 fluorocarbon di-functionalized poly( d,l-lactide), “F2PLA” are described. Small fractions ∼5% w/w of F2PLA, when blended with unfunctionalized poly( d,l-lactide), “PLA”, render the surface both hydrophobic and lipophobic. Contact angle analysis indicates that the properties of the blend surface approach those of PTFE. Rutherford backscattering analysis of the surface shows that at saturation, approximately 50% of the blend surface is covered by C 8F 17 fluorocarbon units. Using self-consistent field theory simulations, we estimate that adsorption of the F2PLA is characterized by a thermodynamic sticking energy of the difunctional group of approximately 6 k BT. Bilayer samples were prepared in which a blend of F2PLA in PLA was initially covered with a layer of pure PLA. The rate of surface modification in these films was analysed to obtain a diffusion coefficient of up to 160 nm 2 s −1 for 21.6 kg/mol F2PLA at 90 °C.

Stereoselective Synthesis of 1,3‐Dienylstannanes by Palladium Catalyzed Cross‐Coupling Reactions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Stereoselective synthesis of 1,3-dienylstannanes by palladium catalyzed cross-coupling reactions

( Z)-α-Bromovinylstannanes are new difunctional group reagents, which undergo palladium catalyzed cross-coupling reactions with ( E)-alkenylzirconium complexes to give stereoselectively 1,3-dienylstannanes in good yields.

Application of organic selenides and tellurides in organic synthesis

AbstractThis paper describes the progress on the synthesis of organic selenides and tellurides and their application in organic synthesis. Low dent selenium and telluronium compounds having high reducing selectivity can be used to form carbon‐hydrogen bonds an special reducing reagents. Telluronium ylides can react with aldehydes and ketones by Wittig‐type condensation to produce (E)‐configuration alkenes stereoselectively. α‐Phenylselanyl arsonium ylides were prepared by transylidation reaction of arsonium ylides with phenylselanyl halides which can undergo Wittig‐type reactions with carbonyl compounds to give (Z)‐α‐selanyl‐α,β‐unsaturated compounds with high stereoselectivity. Zirconium, tin, boron, halogen, metal or hetero‐atom were introduced in organoselenium and telluronium compounds an new difunctional group reagents. Under transition metal catalysis, the corresponding cross coupling reactions provide new methods of formation of carbon‐carbon double bonds, which were used in the stereoselective synthesis of the alkenes.

１，１，１‐トリクロロエタンによるアルミニウムの溶解反応に対する有機試薬の抑制効果に関する統計解析

The inhibiting effect of various organic reagents on the dissolution of aluminum in 1, 1, 1-trichloroethane (CCl3CH3) have been analyzed statistically using data previously obtained on the basis of variance from a) the kind of functional groups, b) the number of functional groups and c) the carbon skeleton structure (aliphatic or aromatic). The results are summarized as follows; 1) The kind of functional group resulted in a recognizable difference in inhibiting effect, which, in the case of monofunctional groups, increased in the order: ethers (A1)<phenols (A2) <alcohols (A3)<esters(A4)<nitrocompounds(A5)<amines(A6)<ketones(A7)<nitriles(A8). Imides (A9) had no inhibiting effect, since they are insoluble in CCl3CH3, 2) There was a clearly recognizable difference between monofunctional and difunctional groups. The quantity of organic reagents added to the CCl3CH3 to inhibit the dissolution of aluminum differed depending on the kind of functional groups, and difunctional groups were lower in concentration than monofunctional groups, at 5 to 45%, 3) There was no recognizable difference in inhibiting effect between aliphatic and aromatic compounds. Standards for the selection of inhibitors are provided by the above analysis.

Prediction of the glass transition temperature of cycloaliphatic amine–epoxy networks

AbstractStoichiometric, completely cured binary or ternary mixtures of the diglycidylether of bisphenol A (DGEBA), isophorone diamine (IPD), and trimethylcyclohexylamine (TMCA) monomers were studied by differential scanning calorimetry. The relations between the glass transition temperature Tg and the structure of the copolymer networks were investigated. Good predictions of Tg can be obtained on the basis of the following hypothesis: (1) the molar contributions MiT−1gi to the “copolymer effect” of difunctional groups are additive, (2) the crosslinking effect can be expressed by the DiMarzio relation in which the molar contribution of crosslink mers is an increasing function of the stiffness of linear segments. For the seven systems under study, the deviation between calculated and experimental Tg values is within experimental scatter.

Kinetics and products of the reactions of nitrate radical with monoalkenes, dialkenes, and monoterpenes

Rate constants for the reactions of NO{sub 3} with a number of aliphatic mono- and dialkenes and monoterpenes have been determined in a 420 1 reaction chamber at 1-bar total pressure of synthetic air by 298 K with a relative kinetic method. The products of these reactions have been investigated also at 1-bar total pressure of synthetic air with in situ FT-IR spectrometry and gas chromatography. In all cases, the initial formation of thermally unstable nitrooxy-peroxynitrate-type compounds containing the difunctional group -CH(OONO{sub 2})-CH(ONO{sub 2})- has been observed.

Glass transition temperature predictions for non-stoichiometric epoxide-amine networks

The glass transition temperature of various diepoxide-diamine binary or diepoxide/diamine/monoamine ternary systems containing an amine or an epoxide excess, was determined by d.s.c. after complete cure. The copolymer effect of various species such as secondary amines and chain ends, was deduced from Di Marzio's approach 7 to the crosslinking effect on T g and the hypothesis of additivity of the group molar contributions M i T gL −1 of the difunctional groups. The results suggest that all tertiary nitrogens, even branching point ones, act as crosslink points. The chain end contribution depends on their structure but can be considered as constant in a given structural series, thus allowing good T g predictions with only one adjustable parameter.

Reaction of Epoxides. IV. Addition of 2, 3-Epoxypropyl Phenyl Ether to Oximes and Hydrazones

Reaction of 2, 3-epoxypropyl phenyl ether with equivalents of aromatic aldoximes and hydrazones in which the difunctional group, the carbon-nitrogen double bond adjacent to the active hydrogen group, is involved in the molecule was attempted in the presence of Lewis acid catalyst. In the result, the 1 : 1 adduct formed by the addition of the epoxide to the active hydrogen group was obtained as the only product, no trace of any cycloaddition product of the epoxide to the carbon-nitrogen double bond being isolated. The structure of the adduct was also discussed.