2204-98-0Relevant academic research and scientific papers
Cobalt-Catalyzed Markovnikov-Selective Radical Hydroacylation of Unactivated Alkenes with Acylphosphonates
Fang, Yewen,He, Jiayan,Li, Chaozhong,Li, Yi,Song, Tao,Zhang, Benxiang
, p. 4955 - 4961 (2021/05/04)
Acylphosphonates having the 5,5-dimethyl-1,3,2-dioxophosphinanyl skeleton are developed as efficient intermolecular radical acylation reagents, which enable the cobalt-catalyzed Markovnikov hydroacylation of unactivated alkenes at room temperature under mild conditions. The protocol exhibits broad substrate scope and wide functional group compatibility, providing branched ketones in satisfactory yields. A mechanism involving the Co-H mediated hydrogen atom transfer and subsequent trapping of alkyl radicals by acylphosphonates is proposed.
Catalytic Asymmetric Acyloin Rearrangements of α-Ketols, α-Hydroxy Aldehydes, and α-Iminols by N, N′-Dioxide-Metal Complexes
Dai, Li,Li, Xiangqiang,Zeng, Zi,Dong, Shunxi,Zhou, Yuqiao,Liu, Xiaohua,Feng, Xiaoming
supporting information, p. 5041 - 5045 (2020/07/03)
A highly enantioselective acyloin rearrangement of cyclic α-ketols has been developed with a chiral Al(III)-N,N′-dioxide complex as catalyst. This strategy provided an array of optically active 2-acyl-2-hydroxy cyclohexanones in moderate to good yields with high enantioselectivities. The asymmetric isomerizations of acyclic α-hydroxy aldehydes and α-iminols were achieved as well under modified conditions, affording the corresponding chiral α-hydroxy ketones and α-amino ketones in moderate results. Moreover, further transformations of product to enantioenriched diols were carried out.
Synthesis of Ketones through Microwave Irradiation Promoted Metal-Free Alkylation of Aldehydes by Activation of C(sp3)-H Bond
Zhang, Xinying,Wang, Zhangxin,Fan, Xuesen,Wang, Jianji
, p. 10660 - 10667 (2015/11/18)
In this paper, a novel methodology for the synthesis of ketones via microwave irradiation promoted direct alkylation of aldehydes by activation of the inert C(sp3)-H bond has been developed. Notably, the reactions were accomplished under metal-free conditions and used commercially available aldehydes and cycloalkanes as substrates without prefunctionalization. By using this novel method, an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established.
Preparation of unsymmetrical ketones from tosylhydrazones and aromatic aldehydes via formyl C-H bond insertion
Allwood, Daniel M.,Blakemore, David C.,Ley, Steven V.
, p. 3064 - 3067 (2014/06/23)
Preparation of ketones by insertion of diazo compounds into the formyl C-H bond of an aldehyde is an attractive procedure, but use of structurally diverse diazo compounds is hampered by preparation and safety issues. A convenient procedure for the synthesis of unsymmetrical ketones from bench-stable tosylhydrazones and aryl aldehydes is reported. The procedure can be performed in one pot from the parent carbonyl compound and needs only a base, with no additional promoters being required.
Direct catalytic asymmetric three-component Kabachnik-fields reaction
Cheng, Xu,Goddard, Richard,Buth, Gernot,List, Benjamin
supporting information; experimental part, p. 5079 - 5081 (2009/03/11)
(Chemical Equation Presented) As mimics of α-amino acids, α-amino phosphonates have great promise as antibacterial and anti-HIV agents as well as protease inhibitors. Racemic α-branched aldehydes react, in the presence the new chiral phosphoric acid catalyst 1, directly with p-anisidine (PMPNH2) and a phosphite to furnish β-branched α-amino phosphonates highly diastereoselectively and enantioselectively. Anth = anthracenyl.
A new efficient and selective synthesis of ketones from alkanes or cycloalkanes, CO, and silanes in the presence of aprotic superacids
Akhrem,Churilova,Orlinkov,Afanas'eva,Vitt,Petrovskii
, p. 918 - 923 (2007/10/03)
A new approach to the direct synthesis of ketones from alkanes or cycloalkanes (RH), CO, and silanes is proposed. Ketones were obtained in 50-97% yields from propane, butane, cyclopentane, cyclohexane, and methylcyclopentane on treatment with CO and silanes (Me4Si, Et4Si, or m-and p-XC6H4SiMe3, where X = Cl, Me, OMe) in the presence of CX4 · 2AlBr3 (X = Br, Cl) superacids at 0 °C. The reactions with m-and p-XC6H4SiMe3 (X = Cl, Me) occur regioselectively to give m-ketones from m-silanes and p-ketones from p-silanes. However, the only product, p-MeOC6H4COR, is formed both from m-and p-MeOC6H4SiMe3. The reaction of Cyclo-C5H9CO+ with BzSiMe3 results in an organosilicon ketone, Me3SiCH2QH4COC5H9, while in the presence of an excess of an acylating system (after alcoholysis), Me2Si(OR′)CH2C6H4COR is formed.
Ring Contraction of 2-Chlorocyclohexanone with Grignard Reagents
Hori, Mikio,Kataoka, Tadashi,Shimizu, Hiroshi,Imai, Eiji,Iwamura, Tatsunori,Maeda, Kaori
, p. 3599 - 3605 (2007/10/02)
The reaction of 2-chlorocyclohexanone with phenylmagnesium bromide in refluxing tetrahydrofuran unexpectedly afforded the ring-contracted product, cyclopentyl phenyl ketone, as the main product in moderate yield.The reactivities of several cyclic 2-haloketones were examined.Keywords - 2-chlorocyclohexanone; Grignard reaction; ring contraction; cyclopentyl phenyl ketone; solvent effect; THF; conformational isomer
