556-82-1Relevant articles and documents
Configurational Stability of a Cyclopropyl Grignard Reagent Containing a Metalated 2-Hydroxymethyl Group
Richey, Herman G.,Moses, L. Meredith
, p. 4013 - 4017 (1983)
Mixtures of cis- and trans-2-bromo-3-(hydroxymethyl)-1,1-dimethylcyclopropane were treated with methylmagnesium bromide to metalate the hydroxyl groups and then with magnesium to form metalated Grignard reagents.The compositions of products obtained upon hydrolysis with D2O indicated that the metalated Grignard reagents in refluxing diethyl ether did not undergo significant cis-trans isomerization.This work provides an example of the configurational stability of a cyclopropyl Grignard reagent with a secondary rather than a tertiary α-carbon.Because of these resultswith cyclopropyl Grignard reagents containing a metalated hydroxyl group, prior observations on additions of allylic Grignard reagents to 3-(hydroxymethyl)cyclopropenes only of products resulting from a cis relationship of magnesium and hydroxymethyl must be due to the stereochemistry of the addition process rather than to a subsequent isomerization.
Reaction of Methylbutenol with Hydroxyl Radical: Mechanism and Atmospheric Implications
Rudich, Yinon,Talukdar, Ranajit,Burkholder, James B.,Ravishankara, A. R.
, p. 12188 - 12194 (1995)
The tropospheric fate of 2-methyl-3-buten-2-ol (methylbutenol, MBO), a recently identified emission by vegetation, was investigated by measuring its UV absorption cross sections (210-300 nm) and the rate coefficient for its reaction with hydroxyl free radicals.UV absorption cross sections were found to be too small for photolysis to be an important removal pathway for MBO in the troposphere.The rate constant applicable under tropospheric conditions for the reaction of OH with MBO was determined to be k=(8.2 +/- 1.2) * 10-12 e((610 +/- 50)/T) cm3 molecule-1 s-1.The OH reaction proceeds mainly via addition of the OH to the double bond in MBO.In the absence of O2, about 15-20percent of the adducts eliminate the alcohol-OH group.However, O2 can scavenge the adduct before it decomposes at T 300 K.This mechanism was confirmed by measuring the rate coefficients for the reactions of OD and 18OH and determining the rate coefficient for the OH reaction in the presence of 7-13 Torr of O2 and in SF6 buffer gas.The elimination of alcohol-OH group was substantiated by observing OH production in the reactions of 18OH and OD.The obtained OH reaction rate coefficient suggests that the primary daytime loss of MBO in the troposphere is via its reaction with OH.
Cationic Ru complexes anchored on POM via non-covalent interaction towards efficient transfer hydrogenation catalysis
Chen, Manyu,Cui, Kai,Hou, Zhenshan,Peng, Qingpo,Wang, Jiajia,Wei, Xinjia,Zhao, Xiuge
, (2021/12/22)
The ionic materials consisting of cationic Ru complexes and Wells-Dawson polyoxometalate anion (POM, K6P2W18O62) have been constructed via a non-covalent interaction. The as-synthesized catalysts have been characterized thoroughly by NMR, XRD, FESEM, and FT-IR, etc. The characterization suggested that a hydrogen bond interaction occurred between the proton of the amine ligand in the cationic Ru complexes and the oxygen atom of the POM anion. The hydrogen bond played an important role in enhancing catalytic activity for the transfer hydrogenation of methyl levulinate (ML) to γ-valerolactone (GVL) under very mild conditions. Especially, the transfer hydrogenation reaction proceeded via a heterogeneous catalysis approach and the heterogenized catalysts even afforded much better catalytic performance than homogeneous analogs. Notably, the catalysts can be recycled without an obvious loss of activity, and further extended to highly selective transfer hydrogenation of α,β-unsaturated ketones and aldehydes, etc. into the corresponding α,β-unsaturated alcohols without any base external additives. The high catalytic performance of these anchored catalysts was highly related to the hydrogen bond interaction and the basicity of the polyanion. The obtained knowledge from this work could lead us to a new catalysis concept of tethering active homogeneous complexes for constructing highly active anchored Ru complex catalysts for hydrogenation reaction.
Ir nanoclusters confined within hollow MIL-101(Fe) for selective hydrogenation of α,β-unsaturated aldehyde
Chen, Yurong,Li, Guangqin,Li, Yinle,Liu, Qian,Liu, Qinghua,Liu, Qinglin,Su, Hui
supporting information, (2021/08/13)
Although the selective hydrogenation of α,β-unsaturated aldehyde to unsaturated alcohol (UOL) is an extremely important transformation, it is still a great challenge to achieve high selectivity to UOL due to thermodynamic favoring of the C[dbnd]C hydrogenation over the C[dbnd]O hydrogenation. Herein, we report that iridium nanoclusters (Ir NCs) confined within hollow MIL-101(Fe) expresses satisfied reaction activity (93.9%) and high selectivity (96.2%) for the hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) under 1 bar H2 atmosphere and room temperature. The unique hollow structure of MIL-101(Fe) benefits for the fast transport of reactant, ensuring the comparable reaction activity and better recyclability of Ir@MIL-101(Fe) than the counterparts which Ir NCs were on the surface of MIL-101(Fe). Furthermore, The X-ray photoelectron spectroscopy data indicates the electropositive Ir NCs, owing to the electron transfer from Ir to MIL-101(Fe), can interact with oxygen lone pairs, and Fourier transform infrared spectrum shows the Lewis acid sites in MIL-101(Fe) can strongly interact with C[dbnd]O bond, which contributes to a high selectivity for COL. This work suggests the considerable potential of synergetic effect between hollow MOFs and metal nanoclusters for selective hydrogenation reactions.
Metal oxide coated ceramic corrugated plate catalyst, preparation and application in preparation of key intermediates of citral
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Page/Page column 9, (2021/04/14)
The present disclosure belongs to the technical field of catalysis, and particularly relates to a metal oxide coated ceramic corrugated plate catalyst, its preparation method and application thereof in preparation of key intermediates of citral. The catalyst consists of a ceramic corrugated plate carrier and a metal oxide active layer coated on a surface of the carrier, wherein the metal oxide active layer is a metal oxide formed by active ingredient titanium and at least four other metal elements selected from vanadium, chromium, manganese, iron, zirconium, niobium and molybdenum.
Nickel-Catalyzed Asymmetric Reductive 1,2-Carboamination of Unactivated Alkenes
He, Jun,Xue, Yuhang,Han, Bo,Zhang, Chunzhu,Wang, You,Zhu, Shaolin
supporting information, p. 2328 - 2332 (2020/01/08)
Starting from diverse alkene-tethered aryl iodides and O-benzoyl-hydroxylamines, the enantioselective reductive cross-electrophilic 1,2-carboamination of unactivated alkenes was achieved using a chiral pyrox/nickel complex as the catalyst. This mild, modular, and practical protocol provides rapid access to a variety of β-chiral amines with an enantioenriched aryl-substituted quaternary carbon center in good yields and with excellent enantioselectivities. This process reveals a complementary regioselectivity when compared to Pd and Cu catalysis.
Scalable synthesis of the aroma compounds d6-β-ionone and d6-β-cyclocitral for use as internal standards in stable isotope dilution assays
Mosaferi, Shabnam,Jelley, Rebecca E.,Fedrizzi, Bruno,Barker, David
supporting information, (2020/12/02)
C13 Norisoprenoids are important aroma compounds in wine, giving positive attributes to the overall wine aroma even when found at very low levels. β-Ionone is considered one of the most important aroma compounds giving violet, woody and raspberry aromas to wine, fruits and vegetables in which it is found. Due to its potent aroma at low levels, precise analytical methods are desired for its quantification. Stable isotope dilution assay (SIDA) is one of the most important of these methods but requires the use of isotopically labelled standards. Herein, we describe the scalable synthesis of d6-β-ionone and d6-β-cyclocitral, another aroma compound with smokey and fruity notes, starting from the relatively inexpensive deuterated starting material d6-acetone.
Visible-Light-Promoted Intramolecular α-Allylation of Aldehydes in the Absence of Sacrificial Hydrogen Acceptors
Liu, Feng,Liu, Jia-Li,tu, Jia-Lin
supporting information, p. 7369 - 7372 (2020/10/05)
We report herein an unprecedented protocol for radical cyclization of aldehydes with pendant alkenes via synergistic photoredox, cobaloxime, and amine catalysis. The transformation was achieved in the absence of external oxidants, providing a variety of 5-, 6-, and 7-membered ring products with alkene transposition in satisfactory yields. The reaction exhibits wide functional group compatibility and occurs under mild conditions with extrusion of H2.
Preparation method of 3-methyl-2-butenol
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Paragraph 0026-0027; 0028-0029; 0030-0031; 0032-0049, (2020/12/08)
The invention provides a preparation method of 3-methyl-2-butenol. The preparation method comprises the following steps: carrying out an isomerization reaction on 2-methyl-3-butene-2-ol in a tubular reactor under the catalysis of a ruthenium catalyst to obtain the 3-methyl-2-butenol. No solvent is added in a reaction process, 2-methyl-3-butene-2-ol is subjected to the isomerization reaction in thetubular reactor to obtain a mixture of the 3-methyl-2-butene-2-ol and the 2-methyl-3-butene-2-ol, the mixture is rectified and separated to obtain the pure 3-methyl-2-butene-2-ol, and the 3-methyl-2-butene-2-ol obtained through recovery is returned to a reaction process, and continues to participate in the reaction. The method has the advantages of simple process flow, few side reactions, high reaction selectivity and high conversion rate.
Engineering Catalysts for Selective Ester Hydrogenation
Dub, Pavel A.,Batrice, Rami J.,Gordon, John C.,Scott, Brian L.,Minko, Yury,Schmidt, Jurgen G.,Williams, Robert F.
, p. 415 - 442 (2020/03/04)
The development of efficient catalysts and processes for synthesizing functionalized (olefinic and/or chiral) primary alcohols and fluoral hemiacetals is currently needed. These are valuable building blocks for pharmaceuticals, agrochemicals, perfumes, and so forth. From an economic standpoint, bench-stable Takasago Int. Corp.'s Ru-PNP, more commonly known as Ru-MACHO, and Gusev's Ru-SNS complexes are arguably the most appealing molecular catalysts to access primary alcohols from esters and H2 (Waser, M. et al. Org. Proc. Res. Dev. 2018, 22, 862). This work introduces economically competitive Ru-SNP(O)z complexes (z = 0, 1), which combine key structural elements of both of these catalysts. In particular, the incorporation of SNP heteroatoms into the ligand skeleton was found to be crucial for the design of a more product-selective catalyst in the synthesis of fluoral hemiacetals under kinetically controlled conditions. Based on experimental observations and computational analysis, this paper further extends the current state-of-the-art understanding of the accelerative role of KO-t-C4H9 in ester hydrogenation. It attempts to explain why a maximum turnover is seen to occur starting at 25 mol % base, in contrast to only 10 mol % with ketones as substrates.
