565-60-6Relevant academic research and scientific papers
Primary Alcohols via Nickel Pentacarboxycyclopentadienyl Diamide Catalyzed Hydrosilylation of Terminal Epoxides
Lambert, Tristan H.,Steiniger, Keri A.
supporting information, p. 8013 - 8017 (2021/10/25)
The efficient and regioselective hydrosilylation of epoxides co-catalyzed by a pentacarboxycyclopentadienyl (PCCP) diamide nickel complex and Lewis acid is reported. This method allows for the reductive opening of terminal, monosubstituted epoxides to form unbranched, primary alcohols. A range of substrates including both terminal and nonterminal epoxides are shown to work, and a mechanistic rationale is provided. This work represents the first use of a PCCP derivative as a ligand for transition-metal catalysis.
Mild-temperature hydrogenation of carbonyls over Co-ZIF-9 derived Co-ZIF-x nanoparticle catalyst
Hu, Ao,Lu, Xinhuan,Pan, Haijun,Wang, Chenlong,Xia, Qinghua,Xia, Yongde,Yang, Lu,Yue, Fanfan,Zhang, Haifu,Zhou, Dan
, (2020/08/21)
Benzimidazole and metal cobalt salts were employed in the synthesis of Co-ZIF-9 by solvothermal crystallization. Highly active catalysts for selective hydrogenation of carbonyl compounds were developed. The optimal nanocatalyst Co-ZIF-350 manifested remarkable activity and selectivity for the hydrogenation of cyclohexanone under mild conditions. Catalytic conversion of cyclohexanone reached the highest over the catalyst of Co-ZIF-9-pyrolyzed at 350 °C for 2 h, in which the conversion of cyclohexanone was 100 % and the selectivity of cyclohexanol was ＞99 % at 50 °C. A wide scope of ketones/aromatic aldehydes could be selectively reduced to the corresponding alcohols with high yields. Importantly, the nanocatalyst Co-ZIF-350 presented good tolerance of substrates with various functional groups under mild conditions.
Systematic Engineering of Single Substitution in Zirconium Metal-Organic Frameworks toward High-Performance Catalysis
Huang, Ning,Yuan, Shuai,Drake, Hannah,Yang, Xinyu,Pang, Jiandong,Qin, Junsheng,Li, Jialuo,Zhang, Yingmu,Wang, Qi,Jiang, Donglin,Zhou, Hong-Cai
supporting information, p. 18590 - 18597 (2017/12/15)
Zirconium-based metal-organic frameworks (Zr-MOFs) exhibit great structural tunability and outstanding chemical stability, rendering them promising candidates for a wide range of practical applications. In this work, we synthesized a series of isostructural PCN-224 analogues functionalized by ethyl, bromo, chloro, and fluoro groups on the porphyrin unit, which allowed us to explicitly study the effects of electron-donating and electron-withdrawing substituents on catalytic performance in MOFs. Owing to the different electronic properties of ethyl, bromo, chloro, and fluoro substitutes, the molecular-level control over the chemical environment surrounding a catalytic center could be readily achieved in our MOFs. To investigate the effects of these substitutes on catalytic activity and selectivity, the oxidation of 3-methylpentane to corresponding alcohols and ketones was utilized as a model reaction. Within these five analogues of PCN-224, an extremely high turnover number of 7680 and turnover frequency of 10 240 h-1 was achieved by simply altering the substitutes on porphyrin rings. Moreover, a remarkable 99% selectivity of the tertiary alcohol over the five other possible by-products are realized. We demonstrate that this strategy can be used to efficiently screen a suitable peripheral environment around catalytic cores in MOFs for catalysis.
Photooxygenation of alkanes by dioxygen with: P -benzoquinone derivatives with high quantum yields
Ohkubo, Kei,Hirose, Kensaku,Fukuzumi, Shunichi
, p. 731 - 734 (2016/07/06)
Alkanes were oxygenated by dioxygen with p-benzoquinone derivatives such as p-xyloquinone in alkanes which are used as solvents to yield the corresponding alkyl hydroperoxides, alcohols and ketones under visible light irradiation with high quantum yields (Φ = 1000, 1600%). The photooxygenation is started by hydrogen atom abstraction from alkanes by the triplet excited states of p-benzoquinone derivatives as revealed by laser-induced transient absorption spectral measurements.
Solvent-Free Photooxidation of Alkanes by Dioxygen with 2,3-Dichloro-5,6-dicyano-p-benzoquinone via Photoinduced Electron Transfer
Ohkubo, Kei,Hirose, Kensaku,Fukuzumi, Shunichi
supporting information, p. 2255 - 2259 (2016/08/30)
Photooxidation of alkanes by dioxygen occurred under visible light irradiation of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) which acts as a super photooxidant. Solvent-free hydroxylation of cyclohexane and alkanes is initiated by electron transfer from alkanes to the singlet and triplet excited states of DDQ to afford the corresponding radical cations and DDQ??, as revealed by femtosecond laser-induced transient absorption measurements. Alkane radical cations readily deprotonate to produce alkyl radicals, which react with dioxygen to afford alkylperoxyl radicals. Alkylperoxyl radicals abstract hydrogen atoms from alkanes to yield alkyl hydroperoxides, accompanied by regeneration of alkyl radicals to constitute the radical chain reactions, so called autoxidation. The radical chain is terminated in the bimolecular reactions of alkylperoxyl radicals to yield the corresponding alcohols and ketones. DDQ??, produced by the photoinduced electron transfer from alkanes to the excited state of DDQ, disproportionates with protons to yield DDQH2.
Facile Protocol for Catalytic Frustrated Lewis Pair Hydrogenation and Reductive Deoxygenation of Ketones and Aldehydes
Mahdi, Tayseer,Stephan, Douglas W.
supporting information, p. 8511 - 8514 (2015/11/27)
A series of ketones and aldehydes are reduced in toluene under H2 in the presence of 5 mol % B(C6F5)3 and either cyclodextrin or molecular sieves affording a facile metal-free protocol for reduction to alcohols. Similar treatment of aryl ketones resulted in metal-free deoxygenation yielding aromatic hydrocarbons.
5-SEC-BUTYL-2-(2,4-DIMETHYL-CYCLOHEX-3-ENYL)-5-METHYL-[1,3]DIOXANE AND PROCESS FOR MAKING THE SAME
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Paragraph 0018; 0019, (2014/04/03)
The present invention is directed to 5-sec-butyl-2-(2,4-dimethyl-cyclohex-3-enyl)-5-methyl-[1,3]dioxane and a novel process for making the same.
5-sec-butyl-2-(2,4-dimethyl-cyclohex-3-enyl)-5-methyl-[1,3]dioxane and process for making the same
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Paragraph 0019, (2014/04/03)
The present invention is directed to 5-sec-butyl-2-(2,4-dimethyl-cyclohex-3-enyl)-5-methyl-[1,3]dioxane and a novel process for making the same.
Tuning a P450 enzyme for methane oxidation
Zilly, Felipe E.,Acevedo, Juan P.,Augustyniak, Wojciech,Deege, Alfred,Reetz, Manfred T.
supporting information; experimental part, p. 2720 - 2724 (2011/06/10)
A new spin: The addition of chemically inert perfluoro carboxylic acids (green; see picture) to P450 enzymes results in dramatic activation of their catalytic activity as a result of the conversion of the Fe/heme from a low-spin to a high-spin state, and the reduction of the binding-pocket size. Together these effects allow otherwise inert substrates such as propane and even methane to be oxidized. Copyright
Structural basis for the properties of two single-site proline mutants of CYP102A1 (P450BM3)
Whitehouse, Christopher J. C.,Yang, Wen,Yorke, Jake A.,Rowlatt, Benjamin C.,Strong, Anthony J. F.,Blanford, Christopher F.,Bell, Stephen G.,Bartlam, Mark,Wong, Luet-Lok,Rao, Zihe
experimental part, p. 2549 - 2556 (2011/10/09)
The crystal structures of the haem domains of Ala330Pro and Ile401Pro, two single-site proline variants of CYP102A1 (P450BM3) from Bacillus megaterium, have been solved. In the A330P structure, the active site is constricted by the relocation of the Pro329 side chain into the substrate access channel, providing a basis for the distinctive C-H bond oxidation profiles given by the variant and the enhanced activity with small molecules. I401P, which is exceptionally active towards non-natural substrates, displays a number of structural similarities to substrate-bound forms of the wild-type enzyme, notably an off-axial water ligand, a drop in the proximal loop, and the positioning of two I-helix residues, Gly265 and His266, the reorientation of which prevents the formation of several intrahelical hydrogen bonds. Second-generation I401P variants gave high in vitro oxidation rates with non-natural substrates as varied as fluorene and propane, towards which the wild-type enzyme is essentially inactive. The substrate-free I401P haem domain had a reduction potential slightly more oxidising than the palmitate-bound wild-type haem domain, and a first electron transfer rate that was about 10 % faster. The electronic properties of A330P were, by contrast, similar to those of the substrate-free wild-type enzyme. Protein evolution with proline: The crystal structures of two contrasting single-site proline mutants of CYP102A1 (P450BM3) have been solved. The two mutations combine to give a variant that shows substantially enhanced catalytic activity with small non-natural substrates (see graph).
