628-55-7Relevant academic research and scientific papers
Characterization by NMR of reactants and products of hydrofluoroether isomers, CF3(CF2)3OCH3 and (CF 3)2C(F)CF2OCH3, reacting with isopropyl alcohol
Knachel, Howard C.,Benin, Vladimir,Moddeman, William E.,Birkbeck, Janine C.,Kestner, Thomas A.,Young, Tanya L.
, p. 407 - 413 (2013)
The 3M Company product Novec 71IPA DL, a mixture of methoxyperfluorobutane, methoxyperfluoroisobutane and 4.5 wt.% isopropyl alcohol, has been found to be very stable at ambient temperature, producing fluoride at the rate of ～1 ppm/year. Our earlier kinetic and theoretical studies have identified the reaction mechanism. This paper identifies the 1H and 19F NMR chemical shifts, multiplicities, and coupling constants of reactants and the major products that result from aging the mixture in sealed Pyrex NMR tubes for periods up to 1.8 years at temperatures from 26 °C to 102 °C. Chemical shifts and coupling constants of fluorine and hydrogen atoms on the hydrofluoroethers and isopropyl alcohol are traced through the reactions to their values in the products - esters, isopropylmethyl ether, and HF. These spectral positions, multiplicities, and coupling constants are presented in table format and as figures to clarify the transformations observed as the samples age. Copyright 2013 John Wiley & Sons, Ltd. The titled hydrofluoroether isomers react slowly with isopropyl alcohol in a two-step process yielding isopropylmethyl ether, the corresponding isopropyl ester isomers, and HF. 19F and 1H NMR chemical shifts, multiplicities, and coupling constants are assigned to the reactants and major products in this paper. Copyright
Application of Yttrium Iron Garnet as a Powerful and Recyclable Nanocatalyst for One-Pot Synthesis of Pyrano[2,3-c]pyrazole Derivatives under Solvent-Free Conditions
Sedighinia,Badri,Kiasat
, p. 1755 - 1763 (2020/01/11)
The application of yttrium iron garnet (YIG) superparamagnetic nanoparticles as a new recyclable and highly efficient heterogeneous magnetic catalyst for one-pot synthesis of pyrano[2,3-c]pyrazole derivatives under solvent-free conditions, as well as etherification and esterification reactions are described. The advantages of the proposed method include the lack of organic solvents, clean reaction, rapid removal of the catalyst, short reaction times, excellent yields, and recyclability of the catalyst.
Antimony(v) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes
Arias Ugarte, Renzo,Devarajan, Deepa,Mushinski, Ryan M.,Hudnall, Todd W.
supporting information, p. 11150 - 11161 (2016/07/20)
1-Diphenylphosphinonaphthyl-8-triphenylstibonium triflate ([2][OTf]) was prepared in excellent yield by treating 1-lithio-8-diphenylphosphinonaphthalene with dibromotriphenylstiborane followed by halide abstraction with AgOTf. This antimony(v) cation was found to be stable toward oxygen and water, and exhibited exceptional Lewis acidity. The Lewis acidity of [2][OTf] was exploited in the catalytic reductive coupling of a variety of aldehydes into symmetric ethers of type L in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [2][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes (M) when aldehydes with 2 α-hydrogen atoms were used. Finally, [2][OTf] catalyzed the cyclotrimerization of aliphatic and aromatic aldehydes to afford the industrially-useful 1,3,5 trioxanes (N) in good yields, and with great selectivity. This phosphine-stibonium motif represents one of the first catalytic systems of its kind that is able to catalyze these reactions with aldehydes in a controlled, efficient manner. The mechanism of these processes has been explored both experimentally and theoretically. In all cases the Lewis acidic nature of the antimony(v) cation was found to promote these reactions.
Silica chloride and boron sulfonic acid as solid acid catalysts in preparation of ethers and esters under solvent-free condition
Elham, Sedighinia,Mozhgan, Zahed Sargoli
supporting information; experimental part, p. 1456 - 1458 (2012/01/06)
Boron sulfonic acid was easily prepared from the reaction of boric acid and chlorosulfonic acid under solvent free condition. The prepared solid acid was supported on silica gel by simple grinding and used as efficient solid acid catalyst in the preparation of ethers from the aliphatic and aromatic alcohols. The ethers were prepared in high isolated yields and in lesser times. Silica chloride was prepared by refluxing of silica gel in thionyl chloride. The obtained solid acid was efficiently used for the conditions of alcohols to the corresponding ethers and acetyl esters in less reaction time and in high isolated yields.
Process for making dibutyl ethers from aqueous isobutanol
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Page/Page column 7-8, (2008/06/13)
The present invention relates to a catalytic process for making dibutyl ethers using a reactant comprising isobutanol and water. The dibutyl ethers so produced are useful in transportation fuels.
The continuous acid-catalyzed dehydration of alcohols in supercritical fluids: A new approach to the cleaner synthesis of acetals, ketals, and ethers with high selectivity
Gray, William K.,Smail, Fiona R.,Hitzler, Martin G.,Ross, Stephen K.,Poliakoff, Martyn
, p. 10711 - 10718 (2007/10/03)
We report a new continuous method for forming ethers, acetals and ketals using solid acid catalysts, DELOXAN ASP or AMBERLYST 15, and supercritical fluid solvents. In the case of ether formation, we observe a high selectivity for linear alkyl ethers with little rearrangement to give branched ethers. Such rearrangement is common in conventional syntheses. Our approach is effective for a range of n-alcohols up to n-octanol and also for the secondary alcohol 2-propanol. In the reaction of phenol with an alkylating agent, the continuous reaction can be tuned to give preferential O- or C- alkylation with up to 49% O-alkylation with supercritical propene. We also investigate the synthesis of a range of cyclic ethers and show an improved method for the synthesis of THF from 1,4-butandiol under very mild conditions.
Hydrogen bonding Part 44 1Thermodynamics of complexation of 3,5-dichlorophenol with ketones and ethers in cyclohexane: The badger-Bauer relationship
Abraham, Michael H.,Prior, David V.,Schulz, Ronald A.,Morris, Jeffrey J.,Taylor, Peter J.
, p. 879 - 885 (2007/10/03)
Equilibrium constants for 1 : 1 hydrogen bond complexation between 3,5-dichioropheno' (DCP) and 17 ketones and 12 ethers in cyclohexane solution have been obtained by an FTIR method that takes into account both diiaerization of the acid and formation of 2 :1 complexes. Enthalpies of complexation for the same ketones and ethers have been determined by a calorimeiric method, leading to values of log K, AG, AH and AS0 for 1 :1 complexation in the 29 systems, as well as log K2 for the 2 :1 complexation between 2 mol of acid and 1 mol of base. For the ketone systems there is very little variation in the three thermodynamic parameters with alkyl substitution, but for the ethers there are systematic variations depending on the alkyl substituent or if the ethers are cyclic. Values of the OH stretching frequency in the DCP complexes with the ketones and ethers in cyclohexane have been obtained. The band shapes for the DCP-ketone complexes are very asymmetric, possibly due to the presence of stereoisomeric complexes, but the VOH band for DCP-ether complexes is symmetric and very suitable for the evaluation of any relationship between v()H and A/f. It is found that for the complexation of DCP with the 12 aliphatic ethers in cyclohexane, there is almost no connection between the calorimetrically determined AH° values and values of AvOH.
Reactivities of Carbonyl Compounds in Acid-Catalyzed Hydride Transfer vs. Electron Transfer
Fukuzumi, Shunichi,Fujita, Morifumi
, p. 2059 - 2062 (2007/10/02)
Rate constants for acid-catalyzed hydride-transfer reactions from triethylsilane to a series of carbonyl compounds are compared with those for acid-catalyzed electron transfer from the excited state of 2+ to the same series of carbonyl compounds in the presence of HClO4 in acetonitrile at 298 K.
Mechanistic Studies of the Catalytic Dehydration of Isobutyl Alcohol on NaH-ZSM-5
Williams, Carol,Makarova, Marina A.,Malysheva, Ludmila V.,Paukshtis, Eugenii A.,Zamaraev, Kirill I.,Thomas, John M.
, p. 3473 - 3485 (2007/10/02)
Using in situ FTIR and GC kinetic studies, we have examined the mechanism of dehydration of isobutyl alcohol to butene on well characterized ZSM-5 zeolite (number of active sites determined by various methods.Dehydration takes place on Broensted-acid sites.The kinetics of water evolution from butanol is followed by in situ FTIR and both the rate constant and the activation energy of water evolution are estimated 2 = k02 exp(-E2/RT), where k02 = 2*109 s-1 and E2 = 19 +/- 3 kcal mol-1>.At low temperatures (45-70 deg C), elimination of water is accompanied by simultaneous formation of isobutyl ether (which at the given temperatures is adsorbed and desorbed with difficulty, but is able to form inside the channels).At higher temperatures (125 deg C), there is a shift in the equilibria of various reaction steps, resulting in the formation of butene.This butene may desorb into the gas phase with traces of ether (in conditions of excess alcohol, flow experiments) or form oligomers which remain adsorbed in the zeolite (no excess of alcohol, static IR experiments).The measured rate constant and activation energy 4 = k04 exp(-E4/RT), where k04 = 3*1014 s-1 and E4 = 32 +/- 2 kcal mol-1> for butene formation are effective values, containing contributions from several reaction steps, which explains the rather high value of E4.
