Tetrahydrofuran

About: Tetrahydrofuran is a(n) research topic. Over the lifetime, 11778 publication(s) have been published within this topic receiving 158241 citation(s). The topic is also known as: diethylene oxide & 1,4-epoxybutane.

An all atom force field for simulations of proteins and nucleic acids.

Abstract: We present an all atom potential energy function for the simulation of proteins and nucleic acids. This work is an extension of the CH united atom function recently presented by S.J. Weiner et al. J. Amer. Chem. Soc., 106, 765 (1984). The parameters of our function are based on calculations on ethane, propane, n−butane, dimethyl ether, methyl ethyl ether, tetrahydrofuran, imidazole, indole, deoxyadenosine, base paired dinucleoside phosphates, adenine, guanine, uracil, cytosine, thymine, insulin, and myoglobin. We have also used these parameters to carry out the first general vibrational analysis of all five nucleic acid bases with a molecular mechanics potential approach.

Synthesis of Imidazol-2-ylidenes by Reduction of Imidazole-2(3H)-thiones

Abstract: An improved synthesis of the title compounds is reported. Reaction of the N,N'-dialkylthioureas 1 with 3-hydroxy-2-butanone gives the imidazole-2(3H)-thiones 2 which on treatment with potassium in boiling tetrahydrofuran give the imidazol-2-ylidenes 3 in excellent yields

Hydrodeoxygenation of Furfural Over Supported Metal Catalysts: A Comparative Study of Cu, Pd and Ni

Abstract: The hydrodeoxygenation of furfural has been investigated over three different metal catalysts, Cu, Pd and Ni supported on SiO2, on a continuous-flow reactor under atmospheric pressure of hydrogen in the 210–290 °C temperature range. The distribution of products is a strong function of the metal catalyst used. High selectivity to furfuryl alcohol is obtained over Cu/SiO2, with the formation of only small amounts of 2-methyl furan at the highest reaction temperature studied. In contrast to Cu catalyst, the conversion of furfural over Pd/SiO2 mainly produces furan by decarbonylation. Furan can further react with hydrogen to form tetrahydrofuran (THF). Finally, on Ni/SiO2 catalysts ring opening products (butanal, butanol and butane) can be obtained in significant amounts. The different product distributions are explained in terms of the strength of interaction of the furan ring with the metal surface and the type of surface intermediates that each metal is able to stabilize.

A stable compound containing a silicon-silicon triple bond.

Abstract: The reaction of 2,2,3,3-tetrabromo-1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyltetrasilane with four equivalents of potassium graphite (KC 8 ) in tetrahydrofuran produces 1,1,4,4-tetrakis[bis(trimethylsilyl)methyl]-1,4-diisopropyl-2-tetrasilyne, a stable compound with a silicon-silicon triple bond, which can be isolated as emerald green crystals stable up to 100°C in the absence of air. The SiSi triple-bond length (and its estimated standard deviation) is 2.0622(9) angstroms, which shows half the magnitude of the bond shortening of alkynes compared with that of alkenes. Unlike alkynes, the substituents at the SiSi group are not arranged in a linear fashion, but are trans-bent with a bond angle of 137.44(4)°.

Catalytic Reduction of Biomass-Derived Furanic Compounds with Hydrogen

Abstract: Furfural and 5-hydroxymethylfurfural (HMF) are important platform chemicals in biorefinery. Reduction of furfural or HMF with H2 over heterogeneous catalysts is the simplest way to convert the oxygen-rich compounds. However, the process can involve many types of reactions such as hydrogenation of the C═O bond, hydrogenation of the furan ring, C–O hydrogenolysis, rearrangement, C–C dissociation, and polymerization. Hydrogenation reactions are most studied in line with hydrogenations of other α,β-unsaturated aldehydes, and it becomes possible to produce each product selectively: furfuryl alcohol, tetrahydrofurfuryl alcohol, 2,5-bis(hydroxymethyl)furan, or 2,5-bis(hydroxymethyl)tetrahydrofuran. Total reduction of side substituents to give 2-methylfuran or 2,5-dimethylfuran is another well-known reaction. Rearrangement and C–O hydrogenolysis reactions have been recently investigated, and they can give useful products such as cyclopentanone, 1,5-pentanediol, and 1,6-hexanediol. Ongoing studies of the reaction ...