513-85-9Relevant articles and documents
Senkus
, p. 913,914 (1946)
Ghanayem,Swann
, p. 1847 (1962)
Reactions of cyclopentanone, γ-butyrolactone, and their derivatives with α-hydroxyethyl radicals
Brinkevich,Reztsov,Shadyro
, p. 303 - 309 (2014)
The interaction of cyclopentanone, 2-cyclopentenone, 1,3-cyclopentanedione, 3-methyl-1,2-cyclopentanedione, γ-butyrolactone, 2(5H)-furanone, ascorbic acid, and 5,6-O-isopropylidenyl-2-3-O-dimethylascorbic acid with α-hydroxyethyl radicals (α-HER) generated during the radiolysis of deaerated ethanol has been studied in the continuous irradiation mode. The test compounds, except γ-butyrolactone, oxidize α-HER. 2(5H)-Furanone and 2-cyclopentenone give hydroxyethylation products via the free-radical chain mechanism. In contrast to 2(5H)-furanone and 2-cyclopentenone, ascorbic and 5,6-O-isopropylidenyl-2,3-O-dimethyl-L-ascorbic acids are weaker oxidants for α-HER and attach these radicals at the multiple carbon-carbon bonds.
Particle size and surface chemistry in photoelectrochemical reactions at semiconductor particles
Müller,Majoni,Memming,Meissner
, p. 2501 - 2507 (1997)
In the present paper reactions at small and large ZnS particles have been investigated. It has been shown that ethanol is selectively oxidized at large (micrometer) particles to acetaldehyde without side products by a "two hole" process. In the case of nanometer particles the primarily formed α-hydroxyethyl radicals in a "one hole" process undergo a secondary reaction, i.e., the dimerization and disproportionation of the free radicals. It has been shown that a two hole process on nanometer particles becomes impossible because the time interval between two successive photon absorption incidents which lead to a successful hole transfer process in a 1-nm particle is much longer than the maximum lifetime of the α-hydroxyethyl radicals formed in the first step. The different mechanisms of ethanol oxidation and the influence of surface chemistry are discussed in detail.
Efficient production of acetoin by the newly isolated Bacillus licheniformis strain MEL09
Liu, Yongfeng,Zhang, Shuling,Yong, Yang-Chun,Ji, Zhixia,Ma, Xin,Xu, Zhenghong,Chen, Shouwen
, p. 390 - 394 (2011)
In this study, a new bacterial strain MEL09, which produces acetoin at high concentrations, was isolated from solid cultures of traditional Chinese vinegar. Based on physiological and biochemical characteristics as well as the 16S rDNA gene sequence, strain MEL09 was identified as Bacillus licheniformis. To improve acetoin production by B. licheniformis MEL09, medium composition and culture conditions were optimized by varying one factor at a time and using orthogonal array tests. Under these optimized conditions, the maximum acetoin concentration achieved was 41.26 g l-1, with 41.26% glucose conversion efficiency (84.39% of theoretical glucose conversion efficiency). This increase is 84.86% over the initial condition and is, to our knowledge, the highest acetoin level ever reported using fermentation methods.
Amplified Rate Acceleration by Simultaneous Up-Regulation of Multiple Active Sites in an Endo-Functionalized Porous Capsule
Kopilevich, Sivil,Müller, Achim,Weinstock, Ira A.
, p. 12740 - 12743 (2015)
Using the hydrolysis of epoxides in water as a model reaction, the effect of multiple active sites on Michaelis-Menten compliant rate accelerations in a porous capsule is demonstrated. The capsule is a water-soluble Ih-symmetry Keplerate-type complex of the form, [{MoVI6O21(H2O)6}12{MoV2O4(L)}30]42-, in which 12 pentagonal "ligands," {(MoVI)MoVI5O21(H2O)6}6-, are coordinated to 30 dimolybdenum sites, {MoV2O4L}1+ (L = an endohedrally coordinated ν2-bound carboxylate anion), resulting in 20 Mo9O9 pores. When "up-regulated" by removal of ca. one-third of the blocking ligands, L, an equal number of dimolybdenum sites are activated, and the newly freed-up space allows for encapsulation of nearly twice as many substrate guests, leading to a larger effective molarity (amplification), and an increase in the rate acceleration (kcat/kuncat) from 16,000 to an enzyme-like value of 182,800.
Selective Photocatalytic C-C Coupling of Bioethanol into 2,3-Butanediol over Pt-Decorated Hydroxyl-Group-Tunable TiO2 Photocatalysts
Yang, Pengju,Zhao, Jianghong,Cao, Baoyue,Li, Li,Wang, Zhijian,Tian, Xuxia,Jia, Suping,Zhu, Zhenping
, p. 2384 - 2390 (2015)
2,3-Butanediol (2,3-BD) was synthesized through TiO2-photocatalytic C-C coupling of bioethanol synchronously with the liberation of an energy H2 molecule in an anaerobic atmosphere. It was found that the selectivity of 2,3-BD is controlled by the amount of .OH. The less the .OH, the higher the 2,3-BD selectivity. Furthermore, it was revealed that the amount of .OH increases with the increasing of the surface OH groups on TiO2 photocatalyst. The introduction of water is in favor of the C-C coupling pathway. This can be attributed to the stronger interaction between water and TiO2, which is beneficial to recovering the OH groups and promoting the desorption of .CH(OH)CH3 intermediates, thus suppressing the thermodynamically favorable overoxidation of .CH(OH)CH3 into acetaldehyde and promoting the C-C coupling into 2,3-BD. Based on the findings, the 2,3-BD selectivity was greatly enhanced from approximately 2.6 % to approximately 65 % over Degussa P25-TiO2 photocatalyst through fluorine substitution of surface OH groups.
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Taub,Dorfman
, p. 4053 (1962)
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Lockhart
, p. 869 (1968)
Direct C-C coupling of bio-ethanol into 2,3-butanediol by photochemical and photocatalytic oxidation with hydrogen peroxide
Li, Na,Yan, Wenjun,Yang, Pengju,Zhang, Hongxia,Wang, Zhijian,Zheng, Jianfeng,Jia, Suping,Zhu, Zhenping
, p. 6029 - 6034 (2016)
Theoretically, selective C-H manipulation in ethanol can result in a direct C-C coupling synthesis of 2,3-butanediol (2,3-BDO). However, this process is typically extremely difficult to achieve because of the high complexity of the involved chemical bonds. In this work, we determine that hydroxide radicals generated from the photolysis of H2O2 can selectively attack the α-hydrogen atom in ethanol aqueous solutions and crack the C-H bond to produce hydroxyethyl radicals, which subsequently undergo C-C coupling to form 2,3-BDO. This selective C-H breakage is determined by the reaction rate, which is primarily controlled by the local H2O2 concentration at a given irradiation intensity. At a moderate reaction rate of ethanol (37 mmol h-1), the 2,3-BDO selectivity reaching as high as 91% can be obtained. The introduction of a catalyst can further increase ethanol conversion and enhance the 2,3-BDO formation rate by controlling the reaction rate. This result provides an environment-friendly approach to convert bio-ethanol directly to 2,3-BDO and to manipulate a single bond selectively in complex bonding situations.
Effects of α-tocopherol and related compounds on reactions involving various organic radicals
Povalishev,Polozov,Shadyro
, p. 1236 - 1239 (2006)
Effects of α-tocopherol, PMC, and a number of the respective sulfur-containing analogues on reactions involving various organic radicals were studied. The test compounds were found to interact with alkyl radicals more effectively than with peroxyl radicals. The presence of a sulfur atom in structures of the respective analogues did not produce significant effects on reactivity. Derivatives of 5-hydroxy-1,3-benzoxathiol-2-one and 6-hydroxy-1,4-benzoxathiin-2(3H)-one displayed a high reactivity toward α-hydroxyalkyl radicals.
C-H activations of methanol and ethanol and C-C couplings into diols by zinc-indium-sulfide under visible light
Zhang, Haikun,Xie, Shunji,Hu, Jinyuan,Wu, Xuejiao,Zhang, Qinghong,Cheng, Jun,Wang, Ye
, p. 1776 - 1779 (2020/02/20)
Herein, an environmentally friendly CoP/Zn2In2S5 catalyst is reported as a visible-light photocatalyst for the selective activation of the α-C-H bond of methanol to generate ethylene glycol with a selectivity of as high as 90%. The catalytic system also illustrates the first example of visible-light-driven dehydrogenative coupling of ethanol to 2,3-butanediol.
Energy- And cost-effective non-sterilized fermentation of 2,3-butanediol by an engineered: Klebsiella pneumoniae OU7 with an anti-microbial contamination system
Guo, Ze-Wang,Ou, Xiao-Yang,Xu, Pei,Gao, Hui-Fang,Zhang, Liao-Yuan,Zong, Min-Hua,Lou, Wen-Yong
, p. 8584 - 8593 (2020/12/31)
Microbial contamination is a serious challenge that needs to be overcome for the successful biosynthesis of 2,3-butanediol (2,3-BD). However, traditional strategies such as antibiotic administration or sterilization are costly, have high energy demands, and may increase the risk of antibiotic resistance. Here, we intend to develop a robust strategy to achieve non-sterilized fermentation of 2,3-BD. Briefly, the robust strain can metabolize unconventional chemicals as essential growth nutrients, and therefore, outcompete contaminant microbes that cannot use unconventional chemicals. To this end, Klebsiella pneumoniae OU7, a robust strain, was confirmed to rapidly exploit urea and phosphite (unconventional chemicals) as the primary sources of nitrogen (N) and phosphorus (P), and withstand deliberate contamination in the possibly contaminated systems. Secondly, metabolic engineering, pathogenicity elimination and adaptive laboratory evolution were successively performed, endowing the best strain with an excellent fermentation performance for safe 2,3-BD production. Finally, 84.53 g L-1 of 2,3-BD was synthesized with a productivity of 1.17 g L-1 h-1 and a yield of 0.38 g g-1 under the non-sterilized system. In summary, our technique reduces labor and energy costs and simplifies the fermentation process because sterilization does not need to be performed. Thus, our work will be beneficial for the sustainable synthesis of 2,3-BD. This journal is