JOURNAL OF ORGANIC CHEMISTRY
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2024
·
IF 3.3
Yangxin Jin,Predrag V. Petrovic,Shuquan Huang,Shibdas Banerjee,Abhijit Nandy,Paul T. Anastas,Jason Chun-Ho Lam
Dehydrogenative aromatization (DA) of cyclic ketones is central to the development of functionalized aromatic precursors and hydrogen transfer–related technologies. Traditional DA strategies require precious metals with oxidants and are typically performed at high temperatures (100–150 °C) to overcome the high energy barrier of aliphatic C–H bond activation. Recently, a mild alternative approach based on I2 has been proposed to realize DA on substituted unsaturated cyclic ketones under ambient conditions. However, depending on the solvent, the product selectivity may vary between phenol ether and phenol, and the reaction mechanisms remain unclear. Herein, based on time-resolved proton nuclear magnetic resonance, DFT calculation, and mass spectrometric analyses, we established a unified mechanism to account for the product distribution. Through substrate scope and desorption electrospray ionization–mass spectrometry, we discovered the formation of a carbocation, which has been overlooked in previous studies. An expanded substrate scope study coupled with spectroscopic observation provided strong evidence to elucidate the formation mechanism and the location of the carbocation. With a renewed understanding of the mechanism, we achieved a phenolic product yield of 17–96% while controlling the selectivity. Moreover, some reactants could undergo DA in H2O, achieving 95–96% yield at below water-boiling temperature.
研究领域:
有机化学
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催化化学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 8
·2078-2088
·
IF 2.372
He Xiaoxia,Chen Yu,Liu Ya,Fang Lina,Chen Zeng,Ji Hongbing
Abstract A series of metal-modified hierarchical M/H-ZSM-5 catalysts were prepared for catalytic conversion of cellulose in an aqueous medium. Characterization of the catalysts showed that the impregnation of metal into H-ZSM-5 did not change the basic framework and pore structure of H-ZSM-5, but it decreased the total acidity. Analysis of the products indicated that the catalysts significantly affected products distribution. When Co/H-ZSM-5 and Fe/H-ZSM-5 were used as the catalysts, the yields of lactic acid and cyclic ketones obviously increased. At last, a recommendable catalytic transformation pathway of cellulose over M/H-ZSM-5 was proposed on the basis of the obtained experimental results and the published literatures. Graphical Abstract In this paper, a series of metal-modified hierarchical M/H-ZSM-5 (M = Ce, Co, Ga, and Fe) catalysts were prepared and employed in catalytic conversion of cellulose in aqueous media to examined the products distribution of cellulose catalytic conversion. Based on our results and previous works, the plausible general reaction pathways of cellulose over M/H-ZSM-5 were proposed.
研究领域:
化学工程
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催化材料科学
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DOI
高影响因子
Molecular Catalysis
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2023
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IF 4.6
Bin Wu,Xiangyun Wang,Bo Yang,Yunjian Ma,Frank Hollmann,Yonghua Wang
In the present work we propose a bienzymatic cascade for the oxyfunctionalisation of cycloalkanes to cyclic alcohols/cyclic ketones. By combining a H 2 O 2 -dependent peroxygenase with a O 2 -consuming and H 2 O 2 -producing alcohol oxidase an overall aerobic oxidation system was established. A convincing proof-of-concept is presented and some current limitations are outlined.
研究领域:
生物化学
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酶工程
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DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 10
·1086
·
IF 4.501
Byu Ri Sim,Jie Gu,Yvette Ley,Shenggan Luo,Yihan Liu,Qin Chen,Yao Nie,Yi-Lei Zhao
Candida parapsilosiscarbonyl reductases (CpRCR) have been widely used for the reductive conversion of ketone precursors and chiral alcohol products in pharmaceutical industries. The enzymatic enantioselectivity is believed to be related to the shape complementation between the cavities in the enzymes and the substitutions of the ketone substrates. In this work, we reported an unexpected enantioselectivity in the enzyme reductions of dihydrofuran-3(2H)-one (DHF) to (S)-tetrahydrofuran-3-ol (DHF-ol, enantiomeric excess: 96.4%), while dihydrothiophen-3(2H)-one substrate (DHT) was unproductive under the same experimental conditions. To rationalize the exclusiveS-configuration and the specific reactivity ofDHF, we carried out molecular dynamics simulations for the reacting complexations ofDHFwithCpRCR, andDHTwithCpRCR. Our calculations indicate thatDHFpreferentially binds to the small cavity near L119, F285, and W286, while the large cavity near theα1helix was mainly occupied by solvent water molecules. Moreover, the pre-reaction state analysis suggests that thepro-Sconformations were more abundant than thepro-R, in particular forDHF. This suggests that the non-polar interaction of substrate C4-C5 methylene contacting the hydrophobic side-chains of L119-F285-W286, and the polar interaction of funanyl oxygen exposing the solvent environment play important roles in the enantioselectivity and reactivity. The phylogenetic tree ofCpRCR homologues implies that a variety of amino acid combinations at positions 285 and 286 were available and thereby potentially useful for redesigning enantioselective reductions of 5-membered-ring heterocyclic ketones.Keywords:carbonyl reductases;enantioselectivity;heterocyclic ketone;molecular modelling
研究领域:
生物化学
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酶工程
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DOI
高影响因子
ENERGY
·
2025
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IF 9.4
Xiaohua Li,Zhitao Lei,Yu Cao,Shanshan Shao,Shiliang Wu
The cycloketones were prepared efficiently via the selectively hydrogenation of aqueous phase lignin-derived single phenolic monomer and mixtures. The yield and selectivity of cycloketones was greatly improved over Br modified metal-acid mixed catalyst (PdH5@Br). First, the effect of side-chain functional structures on the aqueous-phase hydrogenation of phenols with Pd/C catalysis was investigated and it was found that the benzene ring with methyl group attached is more easily hydrogenated, and the phenolic hydroxyl side chain was more susceptible to form carbonyl than methoxy groups. A large number of enols existed, thus the catalyst acidity was adjusted by extra addition of HZSM-5, over which the yield of cycloketones from guaiacol was significantly boosted to 67.9%. Subsequently, the electronic properties of catalyst were altered by adding Br over Pd catalyst, weakening the over-chemisorption of intermediate phenol, and the hydrogenating of phenol under PdH5 were enhanced, thus an increased yield of cycloketone of 18.4% occurred. After the hydrotreating of guiaiacol for 2 h at 523 K and 2 MPa H 2 , the yield of cycloketone reached 80.4% on PdH5@Br. The hydrotreating performance of PdH5@Br with lignin-derived phenolic monomer mixtures as the feedstock was also tested, and it presented great universality and stability. It provides an efficient catalyst system and promising technological ideas for biomass hydrotreating.
研究领域:
化学工程
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可再生资源转化
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2019
·
IF 6.97
Ran Wang,Guangyi Li,Hao Tang,Aiqin Wang,Guoliang Xu,Yu Cong,Xiaodong Wang,Tao Zhang,Ning Li
Decalin is a jet fuel additive with high thermal stability and energy density. Herein, we reported a novel method for the preparation of decalin from cyclopentanone, a hemicellulose derived cycloketone. Ethanolamine acetate (EAOAc), an ionic liquid catalyst which can be derived from biomass, was first applied to the self-aldol condensation of cyclopentanone and demonstrated good activity for this reaction. After the optimization of reaction conditions, ∼83.5% carbon yield of 2-cyclopentylidenecyclopentanone was achieved over the EAOAc catalyst. The hydrodeoxygenation of 2-cyclopentylidenecyclopentanone over a physical mixture of Ru/C and H-β zeolite afforded bi(cyclopentane) which could be further isomerized to decalin. Among the screened catalysts, La-Y zeolite exhibited excellent performance for the isomerization process. According to the characterization results, the high activity of La-Y was rationalized by its large medium-strong acid amount and the appropriate ratio of Brønsted acid to Lewis acid. Analogously, branched decalins were synthesized with cyclohexanone using the same procedure.
研究领域:
化学工程
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能源科学
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催化科学
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产品关联
DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Xue Song,Hongkui Zhang,Jie Zhang,Runchao Sun,Jihong Zhao,Hailiang Zhao,Junkai Hu,Yongde Liu
In this study, a porous carbonaceous adsorbent was prepared from sycamore flocs by pyrolysis method and K2CO3 activation. The effects of preparative conditions of the material on its adsorptive property were explored. The optimal material (SFB2-900) was obtained with a K2CO3/biochar mass ratio of 2:1 at an activation temperature of 900 °C, possessing a huge surface specific area (1651.27 m2/g). The largest adsorption capacity for ciprofloxacin on SFB2-900 was up to 430.25 mg/g. The adsorption behavior was well described by the pseudo-second-order kinetic model and the Langmuir isothermal model. Meanwhile, this process was spontaneous and exothermic. The obtained material showed excellent adsorption performance in the conditions of diverse pH range, ionic strength, and water quality of the solution. The optimum adsorption conditions (pH = 7.01, dosage = 0.6 g/L, and C0 = 52.94 mg/L) determined based on the response surface methodology were in accordance with the practical validation consequences. The good regeneration effect of SFB2-900 manifested that this material had great practical application potential. Combining the experimental results and density functional theory calculation results, the adsorption mechanisms mainly included pore filling, π–π EDA interactions, electrostatic interactions, and H-bonds. The material could be regarded as a novel and high-efficiency adsorbent for antibiotics. Additionally, these findings also provide reference for the reuse of waste biomass in water treatment.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Xiaolong Liu,Jiaxing Zhang,Xue Liu,Kaixuan Yang,Ting Su,Hongying Lü,Peng Wu,Zhiguo Zhu
Catalytic conversions of cyclic ketones into lactones by the Baeyer–Villiger oxidation are particularly attractive for practical applications because catalytic transformations minimize reactant use as well as waste production while simplify processing conditions. Understanding the unique behaviors of highly mesoporous Sn-Beta zeolite catalyst during Baeyer–Villiger oxidation is a challenging research topic. Herein, highly mesopore single-crystalline Sn-Beta zeolite (Sn-Beta-2s) is hydrothermally synthesized via our developed two-step interzeolite transformation strategy. The synthesis mechanism obeys dissolution–recrystallization process, where the degradation step is essential to prepare Sn-Beta-2s zeolite with abundant mesoporous and relatively high hydrophobicity. This single-crystalline Sn-Beta zeolite is adopted to the Baeyer-Villiger oxidation of cyclic ketones as heterogeneous Lewis acid catalyst. Structure-performance relationship reveals that the diffusion performance dominates the product selectivity over three Sn-Beta zeolites. Through the investigation of catalytic mechanism by in-situ FT-IR spectra and DFT calculations, it is found that carbonyl group is activated by zeolitic framework Sn. As for the bulky tert -butyl hydroperoxide oxidant, the reaction can be only triggered on the zeolite surface due to the severe steric constraints within zeolite channels, accounting for the excellent catalytic activity of Sn-Beta-2s zeolite with nanocrystalline nature.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
Biomass Conversion and Biorefinery
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2020
·Vol. 12
·期 12
·5555-5562
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IF 2.602
Wang Yun,Cheng Hong,Li Xiang,Li Li-Ling,Liang Zhi-Hui,Liang Xin-Yi,Chen Xin-Yi
The catalytic promiscuity of MML, lipase from Mucor miehei, was reported to catalyze direct aldol reactions between aromatic aldehydes and cyclic ketones in water, ionic liquids, and deep eutectic solvents at 50 °C. Water can promote the catalytic activity of MML. A wide range of aromatic aldehydes reacted with cyclic ketones to provide the corresponding aldol products with high yields (up to 87.2%) and moderate to good diastereoselectivity (up to 3:97 dr).
研究领域:
生物化学
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绿色化学
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产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2019
·Vol. 36
·期 5
·865-869
·
IF 1.071
Yu Fengli,Chi Yujie,Gao Chong,Chen Ruirui,Xie Congxia,Yu Shitao
A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L -amino acid by utilizing an array of proton sources. The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone. The proline-based ionic liquid [ProH]CF 3 SO 3 was shown to exhibit the best catalytic activity. The reaction condition was optimized to give the following reagent ratio of n (cyclopentanone): n (catalyst): n (H 2 O 2 )=1:0.06:4, 60 °C and 6 h. Under the optimum conditions, the conversion of cyclopentanone was 96.57% and the selectivity for δ-valerolactone was 73.01%. The catalytic activity was shown to be constant after 4 cycles. A simple treatment was allowed for the recover and the reuse of [ProH]CF 3 SO 3 . The successful utilization of [ProH]CF 3 SO 3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of [ProH]CF 3 SO 3 to tolerate variation in the substrate.
研究领域:
有机化学
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催化化学
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产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2016
·
IF 3.389
Mazloom Shah,Qing-Xiang Guo,Yao Fu
The Pd, Ni, Ni-Sn, Cu and Ag@Pd nanocatalyst having different shape and size were used for direct dehydrogenation of cyclic ketones to the corresponding phenols in the presence of O 2 as the oxidant. Among all catalyst tested, metallic Pd-1 nanoparticles exhibited excellent catalytic performance both in presence and absence of p-toluenesulfonic acid. The dehydrogenation of cyclohexanone catalyzed by Pd-1 nanocatalyst led to a 93% yield of the desired cyclohexenone and phenol. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that there was no change in morphology, crystal phases and particles size of Pd-1 nanocatalyst after the reaction.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
Asian Journal of Organic Chemistry
·
2022
·Vol. 11
·期 9
·e202200349
·
IF 3.116
Yan Tang,Meng-Ni Li,Zhen-Yu Huang,Hai-Yang Liu,Xin-Yan Xiao,Si-Quan Zhang
Graphical The cofacial metal xanthene-bridged bis-corroles are applied to catalytic aerobic Baeyer-Villiger oxidation reaction. It turns out iron (IV) bis-corrole complex (Fe 2 XBC) exhibited excellent activity and selectivity towards the B-V oxidation of various cyclic ketones. The yield of ϵ -caprolactone could reach 98% with only 0.005 mol% catalyst. The turnover number (TON) of the Fe 2 XBC catalyst could even be up to 17400 in a gram-scale test of B-V oxidation of cyclohexanone. The metal (M=Co, Cu, Mn, Sn, Fe) xanthene-bridged bis-corroles (M 2 XBC) were synthesized and used for catalyzing aerobic Baeyer-Villiger (B-V) oxidation of cyclic ketones to corresponding lactones. It turns out iron (IV) bis-corrole complex (Fe 2 XBC) exhibited excellent activity and selectivity towards the B-V oxidation of various cyclic ketones at very low catalyst loading. The yield of ϵ -caprolactone could reach 98% with only 0.005 mol% catalyst. The turnover number (TON) of the Fe 2 XBC catalyst could even be up to 17400 in a gram-scale oxidation of cyclohexanone, showing the promising for industrial usage. Moreover, the existences of benzoyl radical and benzoylperoxy radical in the reaction were proved by ESI-HRMS spectra and electron paramagnetic resonance (EPR) spectra. A plausible radical mechanism for the metal bis-corrole catalyzed aerobic B-V oxidation of cyclohexanone in the presence benzaldehyde additive was proposed.
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
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