4571-02-2Relevant 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
supporting information, p. 6631 - 6638 (2021/02/05)
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.
Alpha-hydroxy-ketone compound synthesis method
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Paragraph 0049; 0050; 0051; 0052; 0053, (2017/07/19)
The invention discloses an alpha-hydroxy-ketone compound synthesis method. In the prior art, a noble metal complex, an organophosphorus compound or an iodine elementary substance is always used as a catalyst, the price is high and the recycle cost is higher; used alkali is organic alkali with a complex structure or unusual inorganic alkali such as cesium carbonate which is high in price; a used solvent is always selected from aprotic organic solvents, the post-treatment is complex, and industrialized application is difficult to realize. According to the alpha-hydroxy-ketone compound synthesis method provided by the invention, common inorganic sulfocompounds with low price are adopted as the catalyst, under the alkali and aerobic condition, a carbonyl compound is catalyzed to react to obtain the alpha-hydroxy-ketone compound. The invention has the advantages that the used raw materials are easy to obtain, the price is low, the yield is high, the product purity is high, the waste amount is less and easy to treat, and industrialization is easy to realize.
A novel lanthanum metal-assisted reaction of diaryl ketones and electrophiles
Umeda, Rui,Ninomiya, Masashi,Nishino, Toshiaki,Kishida, Makoto,Toiya, Shunsuke,Saito, Tomoki,Nishiyama, Yutaka,Sonoda, Noboru
, p. 1287 - 1291 (2015/03/05)
A novel and efficient lanthanum metal-assisted carbon-carbon bond formation of diaryl ketones and various electrophiles, such as carbonyl compounds, esters, nitriles, and epoxides, has been developed. When diaryl ketones were allowed to react with dialkyl ketones in the presence of lanthanum metal and a catalytic amount of iodine, the cross pinacol coupling reaction proceeded to give the corresponding unsymmetrical 1,2-diols in moderate to good yields. α-Hydroxy ketones were prepared by the lanthanum metal-assisted reaction of diaryl ketones with esters or nitriles, followed by hydrolysis with aq HCl. It is interesting to note that for the epoxides, the coupling reaction proceeded via the Meinwald rearrangement of epoxides to give the corresponding 1,2-diols.
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.
Aerobic oxygenation of benzylic ketones promoted by a gold nanocluster catalyst
Sakurai, Hidehiro,Kamiya, Ikuyo,Kitahara, Hiroaki,Tsunoyama, Hironori,Tsukudad, Tatsuya
experimental part, p. 245 - 248 (2009/06/23)
Gold nanoclusters stabilized by poly(N-vinyl-2-pyrrolidone) (Au:PVP) promote the oxidation of benzylic ketones, including auto-oxidation-type bond-cleavage reactions and α-hydroxylation, under ambient conditions. The catalyst accelerates the formation of
Aerobic oxidative iodination of ketones catalysed by sodium nitrite "on water" or in a micelle-based aqueous system
Stavber, Gaj,Iskra, Jernej,Zupan, Marko,Stavber, Stojan
experimental part, p. 1262 - 1267 (2010/05/02)
Selective and efficient aerobic oxidative iodination of ketones in aqueous media was achieved by using molecular iodine as the source of iodine atoms, air as the terminal oxidant, sodium nitrite (NaNO2) as the catalyst and H2SO4
Electroreductive acylation of aromatic ketones with acylimidazoles
Kise, Naoki,Agui, Syun,Morimoto, Shinji,Ueda, Nasuo
, p. 9407 - 9410 (2007/10/03)
The intermolecular reductive coupling of aromatic ketones with acylimidazoles was effected by electroreduction in the presence of chlorotrimethylsilane and gave α-trimethylsiloxy ketones and esters. The best result was obtained using Bu4NPF6 as a supporting electrolyte and a Pb cathode in THF. The α-trimethylsiloxy-containing products were transformed to the corresponding α-hydroxy ketones and esters by treatment with TBAF in THF. This method was also effective for the intramolecular reductive coupling of δ- and ε-keto acylimidazoles.
Rhodium-catalyzed addition of arylstannanes to carbon-heteroatom double bond
Oi, Shuichi,Moro, Mitsutoshi,Fukuhara, Hiroe,Kawanishi, Takanori,Inoue, Yoshio
, p. 4351 - 4361 (2007/10/03)
The addition of arylstannanes to the carbon-heteroatom double bond in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN)2]BF4) was examined. The reactions of aldehydes, α-dicarbonyl compounds, and N-substituted aldimines with the arylstannanes gave corresponding alcohols, α-hydroxy carbonyl compounds, and amines, respectively. An arylrhodium complex generated by the transmetalation with the arylstannane was probably the active catalytic species.
Superacid-catalyzed electrocyclization of diphenylmethyl cations to fluorenes. Kinetic and theoretical revisit supporting the involvement of ethylene dications
Ohwada, Tomohiko,Suzuki, Takayoshi,Shudo, Koichi
, p. 4629 - 4637 (2007/10/03)
In superacid media, diphenylmethyl cations bearing an α-carbonyl group generate fluorene compounds. We have obtained chemical evidence showing the acidity dependence of this fluorene cyclization process. A linear relationship was found between the rate of
Organolithium reagents by reductive decyanation of nitriles with lithium and a catalytic amount of 4,4'-di-tert-butyl-biphenyl in a Barbier-type reaction
Guijarro,Yus
, p. 3447 - 3452 (2007/10/02)
The reaction of different nitriles 1 with an excess of lithium powder (1:14 molar ratio) and a catalytic amount of 4,4'-di-tert-butylbiphenyl (5 mol %) in the presence of a carbonyl compound (Barbier-type conditions) in THF at low temperature (-30 or -78°C) leads to the corresponding compounds 2 resulting from the coupling between the electrophile and the organolithium intermediate arising from a reductive decyanation of the starting nitrile 1. This new reaction can be also applied to the use of trimethylchlorosilane as electrophile at 0°C.
