109-68-2Relevant articles and documents
A new olefin synthesis based on the radical induced elimination of a nitro group
Barton, Derek H. R.,Dorchak, Joseph,Jaszberenyi, Joseph Cs.
, p. 8051 - 8054 (1993)
Nitroalkanes can be transformed into olefins in high yielding reactions via nitroolefins and β-nitro trithiocarbonates in radical olefination reactions.
Chirality Inversion in HZSM-5 and Nafion-H Solid Acid-catalysed Synthesis of Ethers from Alcohols via Surface SN2 Reaction
Sun, Qun,Herman, Richard G.,Klier, Kamil
, p. 1849 - 1850 (1995)
A surface-catalysed SN2 reaction is demonstrated for the dehydrative coupling of alcohols to form ethers over heterogeneous acid catalysts, HZSM-5 and Nafion-H, with shape-selectivity playing a major role in the case of HZSM-5 catalyst.
Catalytic dehydrogenation of alcohol over solid-state molybdenum sulfide clusters with an octahedral metal framework
Kamiguchi, Satoshi,Okumura, Kazu,Nagashima, Sayoko,Chihara, Teiji
, p. 188 - 190 (2015)
Abstract Solid-state molybdenum sulfide clusters with an octahedral metal framework, the superconducting Chevrel phases, are applied to catalysis. A copper salt of a nonstoichiometric sulfur-deficient cluster, CuxMo6S8-δ (x = 2.94 and δ ≈ 0.3), is stored in air for more than 90 days. When the oxygenated cluster is thermally activated in a hydrogen stream above 300 °C, catalytic activity for the dehydrogenation of primary alcohols to aldehydes and secondary alcohols to ketones develops. The addition of pyridine or benzoic acid decreases the dehydrogenation activity, indicating that both a Lewis-acidic coordinatively unsaturated molybdenum atom and a basic sulfur ligand synergistically act as the catalytic active sites.
Ultralow-content palladium dispersed in covalent organic framework for highly efficient and selective semihydrogenation of alkynes
Li, Jian Hong,Yu, Zhi Wu,Gao, Zhi,Li, Jian Qiang,Tao, Yuan,Xiao, Yu Xin,Yin, Wen Hui,Fan, Ya Ling,Jiang, Chao,Sun, Li Jun,Luo, Feng
, p. 10829 - 10836 (2019)
Developing noble-metal-based catalysts with ultralow loading to achieve excellent performance for selective hydrogenation of alkynes under mild reaction conditions is highly desirable but still faces huge challenges. To this end, a SO3H-anchored covalent organic framework (COF-SO3H) as the support was deliberately designed, and then ultralow-content Pd (0.38 wt %) was loaded by a wet-chemistry immersion dispersion method. The resulting Pd0.38/COF-SO3H composite exhibits outstanding performance for the selective hydrogenation of phenylacetylene with 97.06% conversion and 93.15% selectivity to styrene under mild reaction conditions (1 bar of H2, 25 °C). Noticeably, the turnover frequency value reaches as high as 3888 h-1, which outperforms most of reported catalysts for such use. Moreover, such a catalyst also exhibits excellent activity for a series of other alkynes and high stability without obvious loss of catalytic performance after five consecutive cycles.
Reactions of Sodium Diisopropylamide: Liquid-Phase and Solid-Liquid Phase-Transfer Catalysis by N, N, N′, N″, N″-Pentamethyldiethylenetriamine
Algera, Russell F.,Collum, David B.,Ma, Yun,Woltornist, Ryan A.
, p. 13370 - 13381 (2021)
Sodium diisopropylamide (NaDA) in N,N-dimethylethylamine (DMEA) and DMEA-hydrocarbon mixtures with added N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDTA) reacts with alkyl halides, epoxides, hydrazones, arenes, alkenes, and allyl ethers. Comparisons of PMDTA with N,N,N′,N′-tetramethylethylenediamine (TMEDA) accompanied by detailed rate and computational studies reveal the importance of the trifunctionality and κ2-κ3 hemilability. Rate studies show exclusively monomer-based reactions of 2-bromooctane, cyclooctene oxide, and dimethylresorcinol. Catalysis with 10 mol % PMDTA shows up to >30-fold accelerations (kcat > 300) with no evidence of inhibition over 10 turnovers. Solid-liquid phase-transfer catalysis (SLPTC) is explored as a means to optimize the catalysis as well as explore the merits of heterogeneous reaction conditions.
Constructing PtI?COF for semi-hydrogenation reactions of phenylacetylene
Li, Jian Hong,Yu, Zhi Wu,Li, Jian Qiang,Fan, Ya Ling,Gao, Zhi,Xiong, Jian Bo,Wang, Li,Tao, Yuan,Yang, Li Xiao,Xiao, Yu Xin,Luo, Feng
, (2020)
The great efforts have been devoted to fabricate excellent hydrogenation catalysts owing to the broad applications in industrial fields. However, the preparation processes of traditional hydrogenation catalysts are often complicated. Herein, mono-valence PtI?COF was synthesized as a catalyst for semi-hydrogenation of phenylacetylene for the first time. The easily prepared SO3H-linked COF possesses a two-dimensional eclipsed layered-sheet structure, making its incorporation with metal ions feasible. The as-prepared PtI?COF composite exhibits excellent performance for semi-hydrogenation phenylacetylene with 93.5% conversion and 90.2% selectivity to styrene under mild reaction conditions (1 ?bar H2, 25 ?°C) within 20 ?min. It's worth noting that the turnover frequency (TOF) value reaches at 3965 h-1, which outperforms most of recently reported excellent Pt-based catalysts for this reaction.
Production of renewable 1,3-pentadiene over LaPO4 via dehydration of 2,3-pentanediol derived from 2,3-pentanedione
Bai, Chenxi,Cui, Long,Dai, Quanquan,Feng, Ruilin,Liu, Shijun,Qi, Yanlong
, (2022/02/07)
1,3-Pentadiene plays an extremely important role in the production of polymers and fine chemicals. Herein, the LaPO4 catalyst exhibits excellent catalytic performance for the dehydration production of 1,3-pentadiene with 2,3-pentanediol, a C5 diol platform compound that can be easily obtained by hydrogenation of bio-based 2,3-pentanedione. The relationships of catalyst structure-acid/base properties-catalytic performance was established, and an acid-base synergy effect was disclosed for the on-purpose synthesis of 1,3-pentadiene. Thus, a balance between acid and base sites was required, and an optimized LaPO4 with acid/base ratio of 2.63 afforded a yield of 1,3-pentadiene as high as 61.5% at atmospheric pressure. Notably, the Br?nsted acid sites with weak or medium in LaPO4 catalyst can inhibit the occurrence of pinacol rearrangement, resulting in higher 1,3-pentadiene production. In addition, the investigation on reaction pathways demonstrated that the E2 mechanism was dominant in this dehydration reaction, accompanied by the assistance of E1 and E1cb.
CATALYST SYSTEMS THAT INCLUDE METAL OXIDE CO-CATALYSTS FOR THE PRODUCTION OF PROPYLENE
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Paragraph 0069-0070, (2020/05/02)
Embodiments of methods of synthesizing a metathesis catalyst system, which include impregnating tungsten oxide on silica support in the presence of a precursor to produce a base catalyst; calcining the base catalyst; impregnating a metal oxide co-catalyst comprising a metal oxide onto the surface of the base catalyst to produce a doped catalyst; and calcining the doped catalyst to produce a metathesis catalyst system. Further embodiments of processes for the production of propylene, which include contacting a hydrocarbon feedstock comprising a mixture of 1-butene and 2-butene with embodiments of the metathesis catalyst system to produce, via metathesis conversion, a product stream comprising propylene.
Multiple C-H Activations of Linear Alkanes by Various (??5-Cyclopentadienyl)W(NO)(CH2CMe3)2 Complexes
Shree, Monica V.,Fabulyak, Diana,Baillie, Rhett A.,Lefèvre, Guillaume P.,Dettelbach, Kevan,Béthegnies, Aurélien,Patrick, Brian O.,Legzdins, Peter,Rosenfeld, Devon C.
supporting information, p. 2714 - 2726 (2017/08/21)
As illustrated in the accompanying diagram, thermolysis of Cp?W(NO)(CH2CMe3)2 (Cp? = n5-C5Me5) at 80 °C in neat linear alkanes effects three successive C-H bond activations of the hydrocarbon substrates and forms Cp?W(NO)(H)(n3-allyl) complexes in which the allyl ligands are derived from the alkanes. These allyl hydrido compounds exist in solutions as mixtures of isomers containing monosubstituted (i.e., terminal) or 1,3-disubstituted (i.e., internal) allyl ligands which can have either an endo or exo orientation with the substituent groups being either proximal or distal to the nitrosyl ligand. Due to steric factors the most abundant isomer in all cases has a monosubstituted allyl ligand in the endo orientation with the alkyl end distal to the nitrosyl ligand. In addition, the relative abundance of Cp?W(NO)(H)(n3-allyl) isomers having monosubstituted allyl ligands decreases with increasing length of the n-alkane chain. Further thermolysis of the Cp?W(NO)(H)(n3-allyl) complexes results in the liberation of alkenes. Whether initiated by Cp?W(NO)(CH2CMe3)2 or independently synthesized Cp?W(NO)(H)(n3-allyl) complexes, the n-alkane dehydrogenations generally result in the preferential formation of 1-alkenes. They are stoichiometric, and their outcomes are not significantly affected by varying the experimental conditions employed (e.g., time, temperature, an open system, use of an H2 acceptor, etc.) or by changing the initial bis(neopentyl) tungsten reactant to its CpEt (n5-C5Me4Et) and CpiPr (n5-C5H4iPr) analogues or to Cp?Mo(NO)(CH2CMe3)2. The results of DFT calculations are consistent with these dehydrogenations proceeding via 16e Cp?M(NO)(n2-alkene) (M = Mo, W) intermediates that are in equilibrium with their more stable 18e Cp?M(NO)(H)(n3-allyl) isomers. These intermediates facilitate the allyl ligand exchange reactions depicted in the accompanying diagram by functioning as internal hydrogen acceptors during the dehydrogenation of the linear alkanes. Thermolysis of the final hydrido allyl complexes liberates the desired alkenes.
Hemilability of the 1,2-Bis(dimethylphosphino)ethane (dmpe) Ligand in Cp?Mo(NO)(κ2-dmpe)
Holmes, Aaron S.,Patrick, Brian O.,Levesque, Taleah M.,Legzdins, Peter
, p. 11299 - 11309 (2017/09/25)
Reaction of Cp?Mo(NO)Cl2 with 1 equiv of 1,2-bis(dimethylphosphino)ethane (dmpe) in THF at ambient temperature forms [Cp?Mo(NO)(Cl)(κ2-dmpe)]Cl (1), which is isolable as an analytically pure yellow powder in 65% yield. Further addition of 2 equiv of Cp2Co to 1 in CH2Cl2 affords dark red Cp?Mo(NO)(κ2-dmpe) (2), which was isolated in 36% yield by recrystallization from Et2O at -30 °C. Reaction of a benzene solution of 2 with an equimolar amount of elemental sulfur results in the immediate production of dark blue (μ-S)[Cp?Mo(NO)(κ1-dmpeS)]2 (3), which is a rare example of a bimetallic transition-metal complex bridged by only a single sulfur atom and involving Mo=S=Mo bonding. In contrast, reaction of 2 with an excess of sulfur in benzene results in the formation of Cp?Mo(NO)(η2-S2)(κ1-dmpeS) (4). Complex 4 can also be formed by the addition of elemental sulfur to 3, thereby indicating that 3 is a precursor to 4. Cp?Mo(NO)(κ2-dmpe) (2) also undergoes interesting transformations when treated with organic bromides. For instance, reaction of 2 with 5 equiv benzyl bromide in THF produces the bimetallic complex (μ-dmpe)[ Cp?Mo(NO)Br2]2 (5) and bibenzyl after 4 d at 70 °C probably via radical intermediates. In contrast to its reaction with benzyl bromide, complex 2 forms [Mo(NO)Br2(κ2-dmpe)]2 (6), olefin, alkane, and Cp?H when treated with 5 equiv of 1-bromopropane or 1-bromooctane in THF at 70 °C for 72 h. Interestingly, complex 2 does not display any reactivity with bromobenzene or 1-bromoadamantane even after being heated for several days at 70 °C. All new complexes were characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them were established by single-crystal X-ray crystallographic analyses.
