60-12-8Relevant articles and documents
Visible light catalyzed anti-markovnikov hydration of styrene to 2-phenylethanol: From batch to continuous
Chen, Yuhang,Zhang, Jie,Tang, Zhiyong,Sun, Yuhan
, (2020)
The 2-phenylethanol production by traditional chemical methods requires multi-step reactions, in which harsh conditions such as high temperature or strong acid/base are required and undesired by-products are easily produced. The visible light catalyzed anti-Markovnikov hydration of styrene is a single-step reaction using non-toxic catalyst under mild conditions. However, this reaction usually takes ten or even dozens of hours, facing the problem in scale up. The present work aims to intensify this reaction in continuous flow microreactor with comparison to traditional batch reactor. The effects of light source shape, reaction temperature, substrate concentration and catalyst concentration on the reaction were investigated. The continuous flow microreactor permitted to ensure more uniform light intensity and larger specific surface area, the reaction rate could thus be enhanced. The maximum productivity of 2-phenylethanol was 0.122 mol/(L.h), which was 2.5 times higher than that obtained in test tube under the same reaction conditions and 34 times higher than that reported in previous literature. The optimal photosensitizer concentration was 2 %. The increase of substrate concentration would lead to the addition reaction between styrene cationic intermediates with styrene, thereby decreasing the selectivity of 2-phenylethanol.
Nitrogen and sulfur co-doped cobalt carbon catalysts for ethylbenzene oxidation with synergistically enhanced performance
Chen, Sheng,Wu, Yujie,Jie, Shanshan,Au, Chak Tong,Liu, Zhigang
, p. 9462 - 9467 (2019)
Heteroatom doping has been demonstrated to be an effective strategy for improving the performance of catalysts. In this paper, cobalt carbon catalysts co-doped with nitrogen and sulfur (N and S) were synthesized through a hydrothermal method with chelate composites involving melamine, thioglycolic acid (C2H4O2S), and tetrahydrate cobalt acetate (Co(OAc)2·4H2O). In addition, the selective oxidation of ethylbenzene under solvent-free conditions with molecular oxygen was used as a probe reaction to evaluate the activity of the catalysts. The optimized catalyst shows an ethylbenzene conversion of 48% with an acetophenone selectivity of 85%. Furthermore, the catalysts were systematically characterized by techniques such as TEM, SEM, XRD, Raman, and XPS. The results reveal that the species of cobalt sulfides and synergistic effects between N and S has inserted a key influence on their catalytic performance.
Ni nanoparticles supported on microwave-synthesised hectorite for the hydrogenation of styrene oxide
Vicente, Isabel,Salagre, Pilar,Cesteros, Yolanda
, p. 31 - 37 (2011)
Three hectorites were synthesised at different preparation conditions by aging with microwaves. One more hectorite was aged by conventional heating for comparison. Synthesized hectorites were used as supports of nickel nanoparticles for the catalytic hydrogenation of styrene oxide to obtain 2-phenylethanol. Ni/hectorite obtained by impregnation of a microwaved-synthesised hectorite with the highest nickel content (10 wt%) resulted in high active, high selective to 2-phenylethanol and high resistant to deactivation catalyst. Catalytic results were related to the different NiO-hectorite interactions observed by TPR together with the accessibility to the acid sites present in the supports. Both factors mainly depended on the hectorite purity and the use of microwaves for hectorite synthesis.
Tetrahedral Sn-silsesquioxane: Synthesis, characterization and catalysis
Beletskiy, Evgeny V.,Shen, Zhongliang,Riofski, Mark V.,Hou, Xianliang,Gallagher, James R.,Miller, Jeffrey T.,Wu, Yuyang,Kung, Harold H.,Kung, Mayfair C.
, p. 15699 - 15701 (2014)
A tetrahedral stannasilsesquioxane complex was synthesized as a racemic mixture using Sn(OiPr)4 and silsesquioxanediol, and its structure was confirmed with X-ray crystallography, NMR, and EXAFS. The complex was a Lewis acid, and both anti and syn-binding with Lewis bases were possible with the formation of octahedral Sn complexes. It was also a Lewis acid catalyst active for epoxide ring opening and hydride transfer.
A study of factors affecting α-(N-carbamoyl)alkylcuprate chemistry
Dieter,Topping,Nice
, p. 2302 - 2311 (2001)
The effect of Cu(I) salt (i.e., CuCN, CuCN·2LiCl, CuI), cuprate reagent, sec-butyllithium quality, solvent, and temperature upon the chemical yields obtained in the reactions of α-(N-carbamoyl)alkylcuprates [i.e., N-Boc-protected α-aminoalkylcuprates] with (E)1-iodo-1-hexene, 5,5-dimethyl-2-cyclohexenone, methylvinyl ketone, crotonate esters, and an acid chloride has been examined. Cuprate conjugate addition and vinylation reactions can succeed with low-quality sec-butyllithium, presumably containing insoluble lithium hydride and lithium alkoxide impurities, although yields are significantly lower than those obtained with high-quality s-BuLi, α-(N-Carbamoyl)alkylcuprates prepared from high-quality sec-butyllithium are thermally stable for 2-3 h at room temperature and are equally effective when prepared from either insoluble CuCN or THF-soluble CuCN·2LiCl. Use of the latter reagent permits rapid cuprate formation at -78 °C, thereby avoiding the higher temperatures required for cuprate formation from THF-insoluble CuCN that are problematic with solutions containing thermally unstable α-lithiocarbamates.
BIOMIMETIC ACTIVATION OF THE C-H BOND. 1. OXYGENATION OF HYDROCARBONS BY ATMOSPHERIC OXYGEN IN THE PRESENCE OF METAL CHLORIDES AND ASCORBIC ACID OR GLUCOSE
Druzhinina, A. N.,Shul'pin, G. B.
, p. 1317 - 1320 (1991)
Oxygenation of hydrocarbons by atmospheric oxygen is initiated by FeCl3, CuCl2, and NaAuCl4 in aqueous acetonitrile in the presence of ascorbic acid or glucose as the reducting agent.Cyclohexane is oxidized to cyclohexanol and cyclohexanone in the presence of ascorbic acid.Ethylbenzene forms acetophenone and 1-phenylethanol in the presence of ascorbic acid or glucose.Styrene is oxidized to form benzaldehyde in general.
Biocatalytic reaction and recycling by using CO2-induced organic-aqueous tunable solvents
Broering, James M.,Hill, Elizabeth M.,Hallett, Jason P.,Liotta, Charles L.,Eckert, Charles A.,Bommarius, Andreas S.
, p. 4670 - 4673 (2006)
(Chemical Equation Presented) Tamed OATS: A scheme that integrates homogeneous biocatalysis in organic-aqueous mixtures with CO2-induced separation has been developed. This method allows for simultaneous product recovery and recycling of the homogeneous biocatalyst for reuse.
Formation of 2-phenylethanol from styrene in the presence of zeolites and UV irradiation
Steilemann, Markus,Armor, John N.,Hoelderich, Wolfgang F.
, p. 697 - 698 (1999)
2-Phenylethanol is formed via an in situ multistep reaction by irradiation of styrene in the presence of silica-alumina compounds such as zeolites in aqueous and methanolic systems; the first step is presumably an oxidation.
A Recyclable Heterogeneous Palladium Catalyst Anchored to Modified Metal-Organic Framework for Hydrogenation of Styrene Oxide
Hossain,Jalil
, p. 1946 - 1950 (2019)
A heterogeneous palladium(II) catalyst anchored to modified metal-organic framework has been synthesized and characterized. The performance of the catalyst has been tested for the hydrogenation of styrene oxide at ambient temperature and pressure. The catalyst showed an excellent activity and selectivity for the preparation of 2-phenylethanol from styrene oxide with 100% conversion and 98% selectivity. The catalyst is very stable and easily recyclable for several times without loss of activity.
Mono- and binuclear complexes of iron(II) and iron(III) with an N 4O ligand: Synthesis, structures and catalytic properties in alkane oxidation
Li, Fei,Wang, Mei,Ma, Chengbing,Gao, Aiping,Chen, Hongbo,Sun, Licheng
, p. 2427 - 2434 (2006)
Three mononuclear iron complexes and one binuclear iron complex, [Fe(tpoen)Cl]·0.5(Fe2OCl6) (1), [Fe(tpoen)Cl]PF6 (2), Fe(tpoen)Cl3 (3) and [{Fe(tpoen)}2(-O)](ClO4)4 (4) (tpoen = N-(2-pyridylmethoxyethyl)-N,N-bis(2-pyridylmethyl)amine), were synthesized as functional models of non-heme iron oxygenases. Crystallographic studies revealed that the Fe(ii) center of 1 is in a pseudooctahedral environment with a pentadentate N4O ligand and a chloride ion trans to the oxygen atom. The Fe(iii) center of 3 is ligated by three nitrogen atoms of tpoen and three chloride ions in a facial configuration. Each Fe(iii) center of 4 is coordinated with four nitrogen atoms and an oxygen atom of tpoen with the Fe-O-Fe angle of 172.0(3) A. Complexes 2, 3 and 4 catalysed the oxidation of cyclohexane with H2O2 in the total TNs of 24-36 with A/K ratios of 1.9-2.4. Under the same conditions they also catalysed both the oxidation of ethylbenzene to benzylic alcohol and acetobenzene with good activity (30-47 TN) and low selectivity (A/K 0.7), and the oxidation of adamantane with moderate activity (15-18 TN) and low regioselectivity (3°/2° 3.0-3.2). With mCPBA as oxidant the catalytic activities of 2, 3 and 4 increased 1.8 to 2.3-fold for the oxidation of cyclohexane and ethylbenzene and 6.3 to 7.5-fold for the oxidation of adamantane. Drastic enhancement of the regioselectivity was observed in the oxidation of adamantane (3°/2° 18.5-30.3). The Royal Society of Chemistry 2006.
