111-43-3Relevant articles and documents
Russell,Hoy
, p. 2018 (1971)
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Vaughn,Vogt,Nieuwland
, p. 511 (1935)
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Tsurugi et al.
, p. 4587 (1969)
Dehydration Pathways of 1-Propanol on HZSM-5 in the Presence and Absence of Water
Zhi, Yuchun,Shi, Hui,Mu, Linyu,Liu, Yue,Mei, Donghai,Camaioni, Donald M.,Lercher, Johannes A.
, p. 15781 - 15794 (2015)
The Br?nsted acid-catalyzed gas-phase dehydration of 1-propanol (0.075-4 kPa) was studied on zeolite H-MFI (Si/Al = 26, containing minimal amounts of extra framework Al moieties) in the absence and presence of co-fed water (0-2.5 kPa) at 413-443 K. It is shown that propene can be formed from monomeric and dimeric adsorbed 1-propanol. The stronger adsorption of 1-propanol relative to water indicates that the reduced dehydration rates in the presence of water are not a consequence of the competitive adsorption between 1-propanol and water. Instead, the deleterious effect is related to the different extents of stabilization of adsorbed intermediates and the relevant elimination/substitution transition states by water. Water stabilizes the adsorbed 1-propanol monomer significantly more than the elimination transition state, leading to a higher activation barrier and a greater entropy gain for the rate-limiting step, which eventually leads to propene. In a similar manner, an excess of 1-propanol stabilizes the adsorbed state of 1-propanol more than the elimination transition state. In comparison with the monomer-mediated pathway, adsorbed dimer and the relevant transition states for propene and ether formation are similarly, while less effectively, stabilized by intrazeolite water molecules.
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Bourhis,R.,Frainnet,E.
, p. 205 - 218 (1975)
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Decarboxylation of dialkyl carbonates to dialkyl ethers over alkali metal-exchanged faujasites
Selva, Maurizio,Fabris, Massimo,Perosa, Alvise
, p. 863 - 872 (2011)
Non-toxic DAlCs, especially lighter dimethyl- and diethyl-carbonate, are regarded as very green alkylating reagents, particularly when coupled with metal-exchanged Y- and X-faujasites as catalysts. These reactions are selective, free from wastes or byproducts, and often require no additional solvent other than the carbonate. Nonetheless, this paper demonstrates that the operating temperature and the nature of the faujasite must be carefully chosen in order to avoid DAlC decomposition. In fact, at temperatures ranging from 150 to 240°C, faujasites can promote decarboxylation of light DAlCs to the corresponding ethers CH3OCH3 and CH3CH 2OCH2CH3 plus CO2. Heavier DAlCs (dipropyl- and dioctyl-carbonate) undergo a similar decomposition pathway, followed by further reactions to the corresponding alcohols (n-propanol and n-octanol) and alkenes [propylene and octene(s)]. These transformations not only consume DAlCs, but also give rise to dangerously flammable ethers, as well as undesirable alcohols, alkenes and CO2. The present work reports an original investigation of the decarboxylation of DAlCs on faujasites with the aim of providing operative boundaries to the experimental conditions to minimise unwanted decomposition. The reaction is strongly affected by the nature of the catalyst: the more basic zeolites, NaX and CsY, are by far more active systems than NaY and LiY. However, solid K2CO3 proves to be rather inefficient. The temperature also plays a crucial role: for example, the onset of the decarboxylation of DMC requires a temperature of ~30°C lower than that for DEC and DPrC. Overall, awareness that certain zeolites cause decomposition of DAlCs under conditions similar to the ones used for DAlC-promoted alkylations allows determination of the correct experimental boundaries for a safer and more productive use of DAlCs as alkylating agents. The Royal Society of Chemistry.
The adsorption and reaction of alcohols on TiO2 and Pd/TiO 2 catalysts
Bahruji, Hasliza,Bowker, Michael,Brookes, Catherine,Davies, Philip R.,Wawata, Ibrahim
, p. 66 - 73 (2013)
The decomposition of alcohols (methanol, ethanol, n-propanol, i-propanol) on TiO2 and Pd/TiO2 catalysts has been studied using temperature programmed desorption. The alcohols mainly decompose via a dehydration pathway on TiO2 catalysts, with no evidence for reactions involving α CC scission or dehydrogenation. However, the reaction pathway was fundamentally altered by the presence of Pd nanoparticles, and products of α CC scission became dominant due to decarbonylation pathways. For the reaction with ethanol, there was no evidence of the dehydration product ethylene even though the surface is mainly composed of titania, indicating that diffusion of alkoxy species from the support to the Pd occurs efficiently during TPD. However, competing dehydration reactions did occur on Pd/TiO2 in the cases of n-propanol and i-propanol decomposition which is postulated to be due to more limited diffusivity of the bulkier alkoxides.
On the miscibility of ethers and perfluorocarbons. An experimental and theoretical study
Babiak, Peter,Němcová, Adriana,Rulí?ek, Lubomír,Beier, Petr
, p. 397 - 401 (2008)
Despite their significant polar character, some organic ethers such as diethyl ether were found to be miscible with perfluorocarbon solvents. Solubilities of various ethers in perfluorocarbons and miscibility temperatures were determined. These properties were found to be greatly dependent on the polarity but also size and shape of the ether molecule. Theoretical calculations of the miscibility temperatures of organic solvents and perfluorocarbons using COSMO-RS method were correlated with experimental data. Considering the difficulties in the accurate description of the macroscopic properties, such as miscibility temperatures, from the first principles, the agreement between experimental and theoretical data is reasonable.
Metal-organic frameworks containing nitrogen-donor ligands for efficient catalytic organic transformations
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Page/Page column 41-43, (2020/06/03)
Metal-organic framework (MOFs) compositions based on nitrogen donor-based organic bridging ligands, including ligands based on 1,3-diketimine (NacNac), bipyridines and salicylaldimine, were synthesized and then post-synthetically metalated with metal precursors, such as complexes of first row transition metals. Metal complexes of the organic bridging ligands could also be directly incorporated into the MOFs. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
Iron-Catalyzed Ring-Closing C?O/C?O Metathesis of Aliphatic Ethers
Biberger, Tobias,Makai, Szabolcs,Lian, Zhong,Morandi, Bill
supporting information, p. 6940 - 6944 (2018/05/14)
Among all metathesis reactions known to date in organic chemistry, the metathesis of multiple bonds such as alkenes and alkynes has evolved into one of the most powerful methods to construct molecular complexity. In contrast, metathesis reactions involving single bonds are scarce and far less developed, particularly in the context of synthetically valuable ring-closing reactions. Herein, we report an iron-catalyzed ring-closing metathesis of aliphatic ethers for the synthesis of substituted tetrahydropyrans and tetrahydrofurans, as well as morpholines and polycyclic ethers. This transformation is enabled by a simple iron catalyst and likely proceeds via cyclic oxonium intermediates.