135366-64-2Relevant academic research and scientific papers
1,5,7-Triazabicyclo[4.4.0]dec-5-ene Enhances Activity of Peroxide Intermediates in Phosphine-Free α-Hydroxylation of Ketones
Wang, Yongtao,Lu, Rui,Yao, Jia,Li, Haoran
, p. 6631 - 6638 (2021)
The critical role of double hydrogen bonds was addressed for the aerobic α-hydroxylation of ketones catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), in the absence of either a metal catalyst or phosphine reductant. Experimental and theoretical investigations were performed to study the mechanism. In addition to initiating the reaction by proton abstraction, a more important role of TBD was revealed, that is, to enhance the oxidizing ability of peroxide intermediates, allowing DMSO to be used rather than commonly used phosphine reductants. Further characterizations with nuclear Overhauser effect spectroscopy (NOESY) confirmed the presence of double hydrogen bonds between TBD and the ketone, and kinetic studies suggested the attack of dioxygen on the TBD-enol adduct to be the rate-determining step. This work should encourage the application of TBD as a catalyst for oxidations.
Monohydroxylation of cyclic and acyclic β-keto esters with molecular oxygen catalyzed by cobalt(II) chloride in neutral conditions
Baucherel, Xavier,Levoirier, Eric,Uziel, Jacques,Juge, Sylvain
, p. 1385 - 1387 (2000)
Cyclic and acyclic α-alkyl-α-hydroxy-β-keto esters 2 were obtained with 50-100% isolated yields from the corresponding β-keto esters 1 by oxidation with molecular oxygen in a mixture of CH3CN/i-PrOH and in the presence of cobalt(II) chloride. (
Formation of δ-Lactones by cyanide catalyzed rearrangement of α-Hydroxy-β-oxoesters
Kieslich, David,Christoffers, Jens
supporting information, p. 953 - 957 (2021/02/06)
δ-Valerolactone derivatives are formed by cyanide-catalyzed ring-transformation of cyclic α-hydroxy-β-oxoesters. This unprecedented reaction defines a new synthetic methodology, and the products are obtained in up to quantitative yields. Several alkyl substitutions as well as different ester residues are tolerated. Furthermore, benzo- and heteroarene-annulated starting materials are converted without problems. As an additional benefit, the starting materials are straightforwardly accessed by cerium-catalyzed aerobic α-hydroxylation of readily available β-oxoesters.
A green synthesis method for vitamin B1 intermediates
-
Paragraph 0013; 0052-0085; 0088-0091, (2022/01/04)
The present invention discloses a green synthesis method of vitamin B1 intermediates, in the presence of a catalyst α - acetyl - γ - butyrolactone under aerobic conditions, reacted in a solvent, to form α - hydroxyacetyl - γ - butyrolactone, and then into the reaction system into hydrogen chloride, in turn substitution reaction and water decarboxyl reaction, to generate vitamin B1 intermediates, i.e., 3-chloro-5-hydroxy-2-pentanone, the catalyst comprises copper salt Lewis acid The method of synthesizing 3-chloro-5-hydroxy-2-pentanone of the present invention can be more environmentally friendly, the equipment corrosive is small and has a higher yield, and can be carried out in one pot, the operation is simpler, the production cost is lower, and it is more suitable for industrial applications.
Aerobic α-hydroxylation of β-keto esters and amides by co-catalysis of SmI3 and I2 under mild base-free conditions
Yu, Shun-Ming,Cui, Kai,Lv, Fei,Yang, Zhen-Yu,Yao, Zhu-Jun
supporting information, p. 2818 - 2821 (2016/06/09)
A clean base-free α-hydroxylation of β-keto esters and amides has been developed, in which air was used as the oxygen source and SmI3 and I2 were applied as the catalysts, affording the corresponding α-hydroxylated 1,3-dicarbonyl pro
Highly efficient C-H hydroxylation of carbonyl compounds with oxygen under mild conditions
Liang, Yu-Feng,Jiao, Ning
supporting information, p. 548 - 552 (2014/01/23)
A transition-metal-free Cs2CO3-catalyzed α-hydroxylation of carbonyl compounds with O2 as the oxygen source is described. This reaction provides an efficient approach to tertiary α-hydroxycarbonyl compounds, which are highly valued chemicals and widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very environmentally friendly and practical. This transformation is highly efficient and highly selective for tertiary C(sp3)-H bond cleavage. OH, so simple! A transition-metal-free Cs2CO 3-catalyzed α-hydroxylation of carbonyl compounds with O 2 provided a variety of tertiary α-hydroxycarbonyl compounds (see scheme; DMSO=dimethyl sulfoxide), which are widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very efficient and practical.
I2-catalyzed direct α-hydroxylation of β-dicarbonyl compounds with atmospheric oxygen under photoirradiation
Miao, Chun-Bao,Wang, Yan-Hong,Xing, Meng-Lei,Lu, Xin-Wei,Sun, Xiao-Qiang,Yang, Hai-Tao
, p. 11584 - 11589 (2013/12/04)
An I2-catalyzed hydroxylation of β-dicarbonyl moieties using air as the oxidant under photoirradiation has been developed for the easy preparation of α-hydroxy-β-dicarbonyl compounds. The transformation was completed with only 1 mol % of I2. With α-unsubstituted malonates, the hydroxylated dimerization product was afforded as the predominant product along with a minor product, α,α-dihydroxyl malonate.
Formal [6+4] cycloaddition of a dicobalt acetylene complex with furan derivatives
Dota, Koichiro,Shimizu, Tadashi,Hasegawa, Shoji,Miyashita, Masaaki,Tanino, Keiji
supporting information; experimental part, p. 910 - 912 (2011/03/21)
An efficient method for constructing a 10-membered carbocycle with an oxygen bridge has been developed on the basis of a formal [6+4] cycloaddition reaction. Under the influence of EtAlCl2, a dicobalt hexacarbonyl acetylene complex possessing a
Iron-catalyzed hydroxylation of β-ketoesters with hydrogen peroxide as oxidant
Li, Dongmei,Schr?der, Kristin,Bitterlich, Bianca,Tse, Man Kin,Beller, Matthias
scheme or table, p. 5976 - 5979 (2009/04/11)
The hydroxylation of β-ketoesters was studied using simple iron catalysts and 30 wt % hydrogen peroxide as the terminal oxidant. The highest activity and yield were achieved in the presence of iron(III) chloride. Cyclic β-ketoesters could be smoothly hydr
Preparation of acyloins by cerium-catalyzed, direct hydroxylation of β-dicarbonyl compounds with molecular oxygen
Christoffers, Jens,Werner, Thomas,Unger, Sven,Frey, Wolfgang
, p. 425 - 431 (2007/10/03)
We report the metal-catalyzed α-hydroxylation of a variety of cyclic and acyclic β-dicarbonyl compounds by molecular oxygen. The decisive advantage of this new method is the use of catalytic amounts of the nontoxic cerium salt CeCl3·7H2O in 2-propanol at ambient temperature. Most of the cyclic substrates 4a-4i give high yields of analytically pure products 5a-5i, and the workup procedure is simple filtration through silica gel. The oxidation of acyclic dicarbonyl compounds 4j-4p, however, is accompanied by side reactions and decomposition, reducing the yields of products 5j-5p significantly. A proposed mechanism is in agreement with experimental results, in particular the observed oxygen uptake. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
