627-27-0Relevant articles and documents
A recoverable Pd nanocatalyst for selective semi-hydrogenation of alkynes: Hydrogenation of benzyl-propargylamines as a challenging model
Uberman, Paula M.,Costa, Natalia J. S.,Philippot, Karine,C. Carmona, Rafaela,Dos Santos, Alcindo A.,Rossi, Liane M.
, p. 4566 - 4574 (2014)
We describe a recyclable heterogeneous palladium nanocatalyst for the selective hydrogenation of alkynes to alkenes. The catalyst was prepared through the decomposition of the organometallic precursor Pd2(dba)3 over a magnetic support, obtaining well-dispersed Pd nanoparticles that formed exclusively on the support surface, with average diameter of 3.5 ± 0.8 nm. The catalytic activity was investigated in the hydrogenation reactions of alkenes and alkynes, and the chemo- and stereoselectivity were evaluated in the hydrogenation of benzyl-propargylamines. The catalyst is highly selective in performing semi-hydrogenation reactions under mild conditions and short reaction times, with good overall yields. Furthermore, it can be easily recovered and recycled, with no leaching of palladium detected, and activities and selectivity retained over multiple reaction cycles. This journal is
Vapor-phase dehydration of 1,4-butanediol to 1,3-butadiene over Y2Zr2O7 catalyst
Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
, (2021/09/16)
Vapor-phase catalytic dehydration of 1,4-butanediol (1,4-BDO) was investigated over Y2O3-ZrO2 catalysts. In the dehydration, 1,3-butadiene (BD) together with 3-buten-1-ol (3B1OL), tetrahydrofuran, and propylene was produced depending on the reaction conditions. In the dehydration over Y2O3-ZrO2 catalysts with different Y contents at 325°C, Y2Zr2O7 with an equimolar ratio of Y/Zr showed high selectivity to 3B1OL, an intermediate to BD. In the dehydration at 360°C, a BD yield higher than 90% was achieved over the Y2Zr2O7 calcined at 700°C throughout 10 h. In the dehydration of 3B1OL over Y2Zr2O7, however, the catalytic activity affected by the calcination temperature is roughly proportional to the specific surface area of the sample. The highest activity of Y2Zr2O7 calcined at 700 °C for the BD formation from 1,4-BDO is explained by the trade-off relation in the activities for the first-step dehydration of 1,4-BDO to 3B1OL and for the second-step dehydration of 3B1OL to BD. The higher reactivity of 3B1OL than saturated alcohols such as 1-butanol and 2-butanol suggests that the C=C double bond of 3B1OL induces an attractive interaction to anchor the catalyst surface and promotes the dehydration. A probable mechanism for the one-step dehydration of 1,4-BDO to BD was discussed.
Selective production of 1,3-butadiene from 1,3-butanediol over Y2Zr2O7 catalyst
Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
, p. 1651 - 1658 (2021/07/21)
The vapor-phase dehydration of 1,3-butanediol (1,3-BDO) to produce 1,3-butadiene (BD) was evaluated over yttrium zirconate, which was prepared through a hydrothermal aging process. 1,3-BDO was initially dehydrated to three unsaturated alcohols, namely 3-buten-2-ol, 3-buten-1-ol, and 2-buten-1-ol, followed by the further dehydration to BD. The catalytic activity of yttrium zirconate was greatly dependent on the calcination temperature. Also, the reaction temperature was one of the important factors to produce BD efficiently. The selectivity to BD was increased with increasing reaction temperature up to 375°C, while coke formation resulted in catalyst deactivation together with by-product formation at higher temperatures. Yttrium zirconate catalyst calcined at 900°C showed a high BD yield of 95% at 375°C and 10 hr on stream.
Preparation method of 3-butene-1-ol
-
Paragraph 0009-0013, (2020/10/05)
The invention relates to a preparation method of 3-butene-1-ol. Ethyl acetate is used as a solvent, allyl bromide, zinc powder, formaldehyde and ammonium chloride are used as raw materials, copper salt is used as a catalyst, and a reaction product is 3-butene-1-ol. The reaction yield is greater than 87%, and the purity is greater than 99%. In order to overcome the defects in the prior art, the catalyst is added, so that the reaction time is greatly shortened; a distillation method is used for replacing multiple times of extraction treatment of the reaction water phase, the operation is easierand more convenient, and the cost is greatly reduced; and an environment-friendly organic matter is used as the solvent, and the green and environment-friendly production concept is met.
Selective oxidation of crotyl alcohol by Au: X Pd bimetallic pseudo-single-atom catalysts
Chivers, Brandon A.,Scott, Robert W. J.
, p. 7706 - 7718 (2020/11/27)
AuPd bimetallic single-atom catalysts are being extensively studied as selective catalysts for hydrogenation and oxidation reactions due to their high selectivity. Previous work in our group has shown that alloy and core-shell AuPd nanoparticle catalysts can selectively oxidize crotyl alcohol to crotonaldehyde at room temperature in base-free conditions. In this work, we discuss the synthesis, extensive characterization, and activity for crotyl alcohol oxidation across a series of AuxPd catalysts (x = 4, 3, 2, and 1) made by both co-reduction and sequential reduction strategies, in order to examine whether single-atom systems can lead to improved activity and/or selectivity for this reaction. X-ray absorption spectroscopy data shows that both co-and sequentially-reduced Au4Pd catalysts have very small Pd-Pd coordination numbers, with values of 1.2 ± 0.3 and 1.6 ± 0.3, respectively, which indicates that they are closest to single-atom systems. The co-Au4Pd catalyst, with the lowest Pd-Pd CN, also exhibits the highest selectivity for the selective oxidation of crotyl alcohol to crotonaldehyde. We were further able to enhance the selectivity of the AuPd nanoparticle catalysts by incorporating vinyl acetate as a hydride scavenger. We show in this paper that dispersing Pd in a Au matrix can lead to very selective catalysts while also lowering the amount of Pd needed in the system.
Dialkyl Ether Formation at High-Valent Nickel
Le Vaillant, Franck,Reijerse, Edward J.,Leutzsch, Markus,Cornella, Josep
supporting information, p. 19540 - 19550 (2020/12/01)
In this article, we investigated the I2-promoted cyclic dialkyl ether formation from 6-membered oxanickelacycles originally reported by Hillhouse. A detailed mechanistic investigation based on spectroscopic and crystallographic analysis revealed that a putative reductive elimination to forge C(sp3)-OC(sp3) using I2 might not be operative. We isolated a paramagnetic bimetallic NiIII intermediate featuring a unique Ni2(OR)2 (OR = alkoxide) diamond-like core complemented by a μ-iodo bridge between the two Ni centers, which remains stable at low temperatures, thus permitting its characterization by NMR, EPR, X-ray, and HRMS. At higher temperatures (>-10 °C), such bimetallic intermediate thermally decomposes to afford large amounts of elimination products together with iodoalkanols. Observation of the latter suggests that a C(sp3)-I bond reductive elimination occurs preferentially to any other challenging C-O bond reductive elimination. Formation of cyclized THF rings is then believed to occur through cyclization of an alcohol/alkoxide to the recently forged C(sp3)-I bond. The results of this article indicate that the use of F+ oxidants permits the challenging C(sp3)-OC(sp3) bond formation at a high-valent nickel center to proceed in good yields while minimizing deleterious elimination reactions. Preliminary investigations suggest the involvement of a high-valent bimetallic NiIII intermediate which rapidly extrudes the C-O bond product at remarkably low temperatures. The new set of conditions permitted the elusive synthesis of diethyl ether through reductive elimination, a remarkable feature currently beyond the scope of Ni.
Synthesis of α,β- and β-Unsaturated Acids and Hydroxy Acids by Tandem Oxidation, Epoxidation, and Hydrolysis/Hydrogenation of Bioethanol Derivatives
Faria, Jimmy,Komarneni, Mallik R.,Li, Gengnan,Pham, Tu,Resasco, Daniel E.,Ruiz, Maria P.,Santhanaraj, Daniel
supporting information, p. 7456 - 7460 (2020/03/23)
We report a reaction platform for the synthesis of three different high-value specialty chemical building blocks starting from bio-ethanol, which might have an important impact in the implementation of biorefineries. First, oxidative dehydrogenation of ethanol to acetaldehyde generates an aldehyde-containing stream active for the production of C4 aldehydes via base-catalyzed aldol-condensation. Then, the resulting C4 adduct is selectively converted into crotonic acid via catalytic aerobic oxidation (62 % yield). Using a sequential epoxidation and hydrogenation of crotonic acid leads to 29 % yield of β-hydroxy acid (3-hydroxybutanoic acid). By controlling the pH of the reaction media, it is possible to hydrolyze the oxirane moiety leading to 21 % yield of α,β-dihydroxy acid (2,3-dihydroxybutanoic acid). Crotonic acid, 3-hydroxybutanoic acid, and 2,3-dihydroxybutanoic acid are archetypal specialty chemicals used in the synthesis of polyvinyl-co-unsaturated acids resins, pharmaceutics, and bio-degradable/ -compatible polymers, respectively.
Palladium-Catalyzed Selective Reduction of Carbonyl Compounds
Sarkar, Nabin,Mahato, Mamata,Nembenna, Sharanappa
, p. 2295 - 2301 (2020/05/18)
Two new examples of structurally characterized β-diketiminate analogues i.e., conjugated bis-guanidinate (CBG) supported palladium(II) complexes, [LPdX]2; [L= {(ArHN)(ArN)–C=N–C=(NAr)(NHAr)}; Ar = 2,6-Et2-C6H3], X = Cl (1), Br (2) have been reported. The synthesis of complexes 1–2 was achieved by two methods. Method A involves deprotonation of LH by nBuLi followed by the treatment of LLi (insitu formed) with PdCl2 in THF, which afforded compound 1 in good yield (75 %). In Method B, the reaction between free LH and PdX2 (X = Cl or Br) in THF allowed the formation of complexes 1 (Yield 73 %) and 2 (Yield 52 %), respectively. Moreover, these complexes were characterized thoroughly by several spectroscopic techniques (1H, 13C NMR, UV/Vis, FT-IR, and HRMS), including single-crystal X-ray structural and elemental analyses. In addition, we tested the catalytic activity of these complexes 1–2 for the hydroboration of carbonyl compounds with pinacolborane (HBpin). We observed that compound 1 exhibits superior catalytic activity when compared to 2. Compound 1 efficiently catalyzes various aldehydes and ketones under solvent-free conditions. Furthermore, both inter- and intramolecular chemoselectivity hydroboration of aldehydes over other functionalities have been established.
Catalytic Dehydration of 1,4-Butanediol over Mg?Yb Binary Oxides and the Mechanism Study
Hu, Zhun,Mi, Rongli,Yang, Bolun,Yi, Chunhai
, (2020/04/10)
In this study, Mg?Yb binary oxides were synthesized using different MgO concentrations and investigated for the catalytic dehydration of 1,4-butanediol (BDO) into 3-buten-1-ol (BTO). The physicochemical properties of the catalysts were characterized by N
Vapor-phase catalytic dehydration of butanediols to unsaturated alcohols over yttria-stabilized zirconia catalysts
Ohtsuka, Shota,Nemoto, Takuma,Yotsumoto, Rikako,Yamada, Yasuhiro,Sato, Fumiya,Takahashi, Ryoji,Sato, Satoshi
, p. 48 - 57 (2019/02/19)
Vapor-phase catalytic dehydration of butanediols (BDOs) such as 1,3-, 1,4-, and 2,3-butanediol was investigated over yttria-stabilized tetragonal zirconia (YSZ) catalysts as well as monoclinic zirconia (MZ). BDOs were converted to unsaturated alcohols with some by-products over YSZ and MZ. YSZ is superior to MZ for these reactions in a view point of selective formation of unsaturated alcohols. Calcination temperature of YSZ significantly affected the products selectivity as well as the conversion of BDOs: high selectivity to unsaturated alcohols was obtained over the YSZ calcined at high temperatures over 800 °C. In the conversion of 1,4-butanediol at 325 °C, the highest 3-buten-1-ol selectivity of 75.3% was obtained over the YSZ calcined at 1050 °C, whereas 2,3-butanediol was less reactive than the other BDOs. In the dehydration of 1,3-butanediol at 325 °C, in particular, it was found that a YSZ catalyst with a Y2O3 content of 3.2 wt.% exhibited an excellent stable catalytic activity: the highest selectivity to unsaturated alcohols such as 2-buten-1-ol and 3-buten-2-ol over 98% was obtained at a conversion of 66%. Structures of active sites for the dehydration of 1,3-butanediol were discussed using a crystal model of tetragonal ZrO2 and a probable model structure of active site was proposed. The well-crystalized YSZ inevitably has oxygen defect sites on the most stable surface of tetragonal ZrO2 (101). The defect site, which exposes three cations such as Zr4+ and Y3+, is surrounded by six O2? anions. The selective dehydration of 1,3-butanediol to produce 3-buten-2-ol over the YSZ could be explained by tridentate interactions followed by sequential dehydration: the position-2 hydrogen is firstly abstracted by a basic O2? anion and then the position-1 hydroxyl group is subsequently or simultaneously abstracted by an acidic Y3+ cation. Another OH group at position 3 plays an important role of anchoring 1,3-butanediol to the catalyst surface. Thus, the selective dehydration of 1,3-butanediol could proceed via the speculative base-acid-concerted mechanism.
