591-93-5Relevant academic research and scientific papers
CATALYTIC HYDROCARBON DEHYDROGENATION
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Paragraph 0056; 0122; 0123, (2021/03/13)
A catalyst for dehydrogenation of hydrocarbons includes a support including zirconium oxide and Linde type L zeolite (L-zeolite). A concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %. The catalyst includes from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal. The catalyst includes from 0.1 wt. % to 10 wt. % of tin. The catalyst includes from 0.1 wt. % to 8 wt. % of a platinum group metal. The alkali metal or alkaline earth metal, tin, and platinum group metal are disposed on the support.
Phosphonate-Modified UiO-66 Br?nsted Acid Catalyst and Its Use in Dehydra-Decyclization of 2-Methyltetrahydrofuran to Pentadienes
Caratzoulas, Stavros,Chen, Tso-Hsuan,Dauenhauer, Paul,Dorneles de Mello, Matheus,Han, Songi-I,Jain, Sheetal K.,Kumar, Gaurav,Li, Xinyu,Scott, Susannah L.,Tabassum, Tarnuma,Tsapatsis, Michael,Vlachos, Dionisios G.
supporting information, p. 13260 - 13266 (2020/06/08)
Phosphorus-modified all-silica zeolites exhibit activity and selectivity in certain Br?nsted acid catalyzed reactions for biomass conversion. In an effort to achieve similar performance with catalysts having well-defined sites, we report the incorporation of Br?nsted acidity to metal–organic frameworks with the UiO-66 topology, achieved by attaching phosphonic acid to the 1,4-benzenedicarboxylate ligand and using it to form UiO-66-PO3H2 by post-synthesis modification. Characterization reveals that UiO-66-PO3H2 retains stability similar to UiO-66, and exhibits weak Br?nsted acidity, as demonstrated by titrations, alcohol dehydration, and dehydra-decyclization of 2-methyltetrahydrofuran (2-MTHF). For the later reaction, the reported catalyst exhibits site-time yields and selectivity approaching that of phosphoric acid on all-silica zeolites. Using solid-state NMR and deprotonation energy calculations, the chemical environments of P and the corresponding acidities are determined.
Dehydra-decyclization of 2-methyltetrahydrofuran to pentadienes on boron-containing zeolites
Dauenhauer, Paul J.,Kumar, Gaurav,Liu, Dongxia,Ren, Limin,Tsapatsis, Michael,Xu, Dandan
supporting information, p. 4147 - 4160 (2020/07/14)
1,3-Pentadiene (piperylene) is an important monomer in the manufacturing of adhesives, plastics, and resins. It can be derived from biomass by the tandem ring-opening and dehydration (dehydra-decyclization) of 2-methyltetrahydrofuran (2-MTHF), but competing reaction pathways and the formation of another isomer (1,4-pentadiene) have limited piperylene yields to MFI > BEA at a given temperature (523 K), indicating the non-identical nature of active sites in these weak solid acids. The diene distribution remained far from equilibrium and was tuned towards the desirable conjugated diene (1,3-pentadiene) by facile isomerization of 1,4-pentadiene. This tuning capability was facilitated by high bed residence times, as well as the smaller micropore sizes among the zeolite frameworks considered. The suppression of competing pathways, and promotion of 1,4-pentadiene isomerization events lead to a hitherto unreported ～86percent 1,3-pentadiene yield and an overall ～89percent combined linear C5 dienes' yield at near quantitative (～98percent) 2-MTHF conversion on the borosilicate B-MWW, without a significant reduction in diene selectivities for at least 80 hours time-on-stream under low space velocity (0.85 g reactant per g cat. per h) and high temperature (658 K) conditions. Finally, starting with iso-conversion levels (ca. 21-26percent) and using total turnover numbers (TONs) accrued over the entire catalyst lifetime as the stability criterion, borosilicates were demonstrated to be significantly more stable than aluminosilicates under reaction conditions (～3-6× higher TONs).
Efficient Generation and Synthetic Applications of Alkyl-Substituted Siloxycarbenes: Suppression of Norrish-Type Fragmentations of Alkanoylsilanes by Triplet Energy Transfer
Abe, Manabu,Hagiwara, Chihiro,Ishida, Kento,Kusama, Hiroyuki,Yamazaki, Hokuto
, p. 1249 - 1253 (2020/02/04)
Acylsilanes have been known to undergo isomerization to siloxycarbenes under photoirradiation and the thus generated carbenes can be utilized for various synthetic reactions. But this carbene formation is not necessarily efficient with some alkanoylsilanes because Norrish-type fragmentations compete, which limit the synthetic utility of alkanoylsilanes as carbene precursors. In this study, generation of siloxycarbenes from alkanoylsilanes by visible-light-induced energy transfer was examined by using an Ir complex, [Ir{dF(CF3)ppy}2(dtbpy)]PF6, and was successfully applied to the C?C coupling reactions with boronic esters or aldehydes. This methodology efficiently suppressed undesired Norrish-type reactions and broadened synthetic utility of alkanoylsilanes.
One-pot Synthesis of 1,3-Butadiene and 1,6-Hexanediol Derivatives from Cyclopentadiene (CPD) via Tandem Olefin Metathesis Reactions
Turczel, Gábor,Kovács, Ervin,Csizmadia, Eszter,Nagy, Tibor,Tóth, Imre,Tuba, Robert
, p. 4884 - 4891 (2018/09/25)
A novel tandem reaction of cyclopentadiene leading to high value linear chemicals via ruthenium catalyzed ring opening cross metathesis (ROCM), followed by cross metathesis (CM) is reported. The ROCM of cyclopentadiene (CPD) with ethylene using commercially available 2nd gen. Grubbs metathesis catalysts (1-G2) gives 1,3-butadiene (BD) and 1,4-pentadiene (2) (and 1,4-cyclohexadiene (3)) with reasonable yields (up to 24 % (BD) and 67 % (2+3) at 73 % CPD conversion) at 1–5 mol % catalyst loading in toluene solution (5 V% CPD, 10 bar, RT) in an equilibrium reaction. The ROCM of CPD with cis-butene diol diacetate (4) using 1.00 - 0.05 mol % of 3rd gen. Grubbs (1-G3) or 2nd gen. Hoveyda-Grubbs (1-HG2) catalysts loading gives hexa-2,4-diene-1,6-diyl diacetate (5), which is a precursor of 1,6-hexanediol (an intermediate in polyurethane, polyester and polyol synthesis) and hepta-2,5-diene-1,7-diyl diacetate (6) in good yield (up to 68 % or TON: 1180). Thus, convenient and selective synthetic procedures are revealed by ROCM of CPD with ethylene and 4 leading to BD and 1,6-hexanediol precursor, respectively, as key components of commercial intermediates of high-performance materials.
Ring Opening of Biomass-Derived Cyclic Ethers to Dienes over Silica/Alumina
Kumbhalkar, Mrunmayi D.,Buchanan, J. Scott,Huber, George W.,Dumesic, James A.
, p. 5248 - 5256 (2017/08/17)
We show that cyclic ethers, such 2-methyltetrahydrofuran (2-MTHF), can undergo dehydration to produce pentadienes over SiO2/Al2O3. The catalyst exhibited reversible deactivation due to coke deposition, with the yield to pentadienes decreasing from 68% to 52% at 623 K over 58 h time on stream. A reaction network for 2-MTHF dehydration was proposed on the basis of the results of space time studies. Pentadienes can be produced directly by a concerted hydride shift and dehydration of carbenium intermediates or indirectly through dehydration of pentanal and pentenol. Reaction kinetics studies were performed at temperatures ranging from 573 to 653 K and 2-MTHF partial pressures from 0.21 to 2.51 kPa. The apparent activation energy barrier for 2-MTHF conversion to pentadienes and the reaction rate order for ring opening were determined to be 74 kJ mol-1 and 0.24, respectively, indicating strong interaction between 2-MTHF and the SiO2/Al2O3 surface. Other solid acids such as γ-Al2O3, H-ZSM-5, and Al-Sn-Beta were found to be active for 2-MTHF dehydration to pentadienes. The rate of ring opening decreased in the order 2,5-dimethyltetrahydrofuran > 2-MTHF > tetrahydropyran > tetrahydrofuran. Over SiO2/Al2O3, the dehydration of 2,5-dimethyltetrahydrofuran resulted in 75% yield to hexadiene isomers. (Figure Presented).
Study of the Formation of the First Aromatic Rings in the Pyrolysis of Cyclopentene
Herbinet, Olivier,Rodriguez, Anne,Husson, Benoit,Battin-Leclerc, Frédérique,Wang, Zhandong,Cheng, Zhanjun,Qi, Fei
, p. 668 - 682 (2016/02/23)
The thermal decomposition of cyclopentene was studied in a jet-stirred reactor operated at constant pressure and temperature to provide new experimental information about the formation of the first aromatic rings from cyclic C5 species. Experim
Enzymatic Oxidative Tandem Decarboxylation of Dioic Acids to Terminal Dienes
Dennig, Alexander,Kurakin, Sara,Kuhn, Miriam,Dordic, Andela,Hall, Mélanie,Faber, Kurt
supporting information, p. 3473 - 3477 (2016/07/29)
The biocatalytic oxidative tandem decarboxylation of C7–C18dicarboxylic acids to terminal C5–C16dienes was catalyzed by the P450 monooxygenase OleT with conversions up to 29 % for 1,11-dodecadiene (0.49 g L–1). The sequential nature of the cascade was proven by the fact that decarboxylation of intermediate C6–C11ω-alkenoic acids and heptanedioic acid exclusively gave nonconjugated 1,4-pentadiene; scale-up allowed the isolation of 1,15-hexadecadiene and 1,11-dodecadiene; the system represents a short and green route to terminal dienes from renewable dicarboxylic acids.
Stereo- and chemoselective character of supported CEO2 catalysts for continuous-flow three-phase alkyne hydrogenation
Vile, Gianvito,Wrabetz, Sabine,Floryan, Leonard,Schuster, Manfred Erwin,Girgsdies, Frank,Teschner, Detre,Perez-Ramirez, Javier
, p. 1928 - 1934 (2014/08/05)
TiO2-, Al2O3-, and ZrO2- supported CeO2 catalysts with different Ce loadings were prepared by wet impregnation of the carriers with an acidified solution of cerium ammonium nitrate. The calcined catalysts were characterized by bulk and surface-sensitive techniques, which included microcalorimetry, and evaluated in the three-phase hydrogenation of alkynes under continuous-flow conditions at variable temperature (293-413 K) and pressure (1-90 bar). A number of acetylenic compounds, which contain terminal or internal triple bonds, conjugated unsaturations, and additional functionalities, were systematically assessed. The results revealed the full stereo- and chemoselective character of the ceria catalysts, which outperform the well-known Lindlar catalyst, and open promising perspectives for the revolutionary use of a cost-effective oxide for the production of olefinic compounds in the vitamin and fine chemical industries.
RENEWABLE ACRYLIC ACID PRODUCTION AND PRODUCTS MADE THEREFROM
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Paragraph 00140; 00141; 00142; 00143, (2014/01/08)
Processes and methods for making biobased acrylic acid products including acrylic acid, acrylic acid oligomers, acrylic acid esters, acrylic acid polymers and articles from renewable carbon resources are described herein.
