5350-76-5Relevant academic research and scientific papers
Preparation method of aryl ketone
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Paragraph 0064-0068, (2021/10/11)
The invention discloses a preparation method of aryl ketone. The preparation method comprises the following steps: mixing a phenyl epoxy compound, aryl trifluoromethanesulfonate, a phosphine ligand, a nickel source, alkali and an organic solvent, and conducting reacting in one step under the protection of inert gas to generate aryl ketone. The preparation method disclosed by the invention is simple in process, mild in conditions and low in cost, and paves a way for large-scale industrial production application, such as drug synthesis or natural product synthesis application, of aryl ketone serving as an important organic reaction intermediate.
Ring size and nothing else matters: unusual regioselectivity of alkyne hydration by NHC gold(i) complexes
Ageshina, Alexandra A.,Asachenko, Andrey F.,Chesnokov, Gleb A.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Philippova, Anna N.,Rzhevskiy, Sergey A.,Topchiy, Maxim A.
supporting information, p. 5686 - 5689 (2021/06/16)
We have investigated the role of ring sizes and substituents in NHC ligands in some (NHC)Au(i) complexes in the hydration of internal alkynes. Despite the fact that using (NHC)Au(i) complexes in the hydration of diarylacetylenes leads to Markovnikov-type products, the precise tuning of ligands allows changing the regioselectivity in arylalkylacetylene hydration to the anti-Markovnikov-type.
Heck reactions of α- or β-substituted enol ethers with aryl bromides catalysed by a tetraphosphane/palladium complex - Direct access to acetophenone or 1-arylpropanone derivatives
Battace, Ahmed,Feuerstein, Marie,Lemhadri, Mhamed,Zair, Touriya,Doucet, Henri,Santelli, Maurice
, p. 3122 - 3132 (2008/02/08)
cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphanylmethyl)cyclopentane/ [PdCl(C3H5)]2 efficiently catalyses the Heck reaction of α- and β-substituted enol ethers with aryl bromides. The arylation of 1-phenyl-1-(trimethylsilyloxy) ethylene led directly to the 2-aryl-1-phenylethanones. Similar reaction rates were observed with electron-rich, electron-deficient or sterically congested aryl bromides. Heck reaction with benzyl isopropenyl ether gave a mixture of isomers. However, this mixture gave selectively the 1-arylpropanones after hydrolysis. Employing β-methoxystyrene, 3-ethoxyacrylonitrile or methyl 3-methoxyacrylate, the regioselective α-arylation of these enol ethers was observed in all cases, but mixtures of (Z) and (E) isomers were generally obtained, which in many cases yielded a single ketone product after acid treatment. The stereoselectivity of this reaction depends on steric and electronic factors, and better stereoselectivities in favour of (Z) isomers were observed with electron-rich or sterically congested aryl bromides. Higher yields were obtained for this reaction with electron-rich or sterically congested aryl bromides than with electron-poor aryl bromides. These observations suggest that the rate-limiting step of the catalytic cycle is not the oxidative addition of the aryl bromide to the palladium complex with these substituted enol ethers. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Photocyclization of -(o-Tolyl)acetophenones: Triplet and 1,5-biradical reactivity
Wagner, Peter J.,Meador, Michael A.,Zhou, Boli,Park, Bong-Ser
, p. 9630 - 9639 (2007/10/02)
Several ring-substituted α-(o-tolyl)acetophenones undergo photocyclization to 2-indanol derivatives in high quantum efficiency in solution and in high chemical yield as solids. The mechanism for reaction involves triplet state δ-hydrogen atom abstraction that generates 1,5-biradicals. Quenching studies indicate that the n.π* excited triplets of these ketones react, with rate constants >108 s-1. Variations in triplet reactivity are ascribed to conformational equilibria that populate reactive and unreactive geometries to different extents. The α-aryl ring eclipses the carbonyl in the lowest energy geometry, from which the most favorable geometry for reaction can be reached by small bond rotations. α-(2,4,6-Triisopropylpheny)acetophenone forms the relatively long lived enol as well as indanol in solvent-dependent ratios; deuterium labeling indicates that the 1,5-biradical disproportionates to form enol. This does not happen with α-mesitylacetophenone, so its 54% cyclization quantum efficiency is ascribed to an internal triplet quenching that competes with hydrogen abstraction. This internal quenching is presumed to be of the charge-transfer type and does not appear to lead directly to 1,5-biradicals. 1-Methyl-2-phenyl-2-indanol is formed from α-(o-ethylpheny)acetophenone with a Z/E ratio of 20:1 in benzene and 2:1 in methanol. The 1,5-biradical intermediates were characterized by flash spectroscopy; they have lifetimes between 15 and 45 ns, with those derived from α-(o-isopropylphenyl) ketones being twice as long-lived as those derived from α-(o-methylphenyl) ketones, and show only a small solvent dependence. Biradical lifetimes and the diastereoselectivity of cyclization are interpreted in terms of biradical intersystem crossing occurring preferentially along the reaction coordinate for cyclization, such that the two processes effectively occur concurrently. The applicability of this concept to other biradicals is discussed.
DURCH STERISCHE EFFEKTE STABILISIERTE β-KETOCARBONSAEUREN
Meier, Herbert,Wengenroth, Horst,Lauer, Wolfgang,Krause, Volker
, p. 5253 - 5256 (2007/10/02)
Increasing steric hindrance in β-keto carboxylic acids leads to an increasing kinetic stability towards decarboxylation, till systems are reached wich are completely stable at room temperature.Simultaneously the tautomeric equilibrium is changed in favour of the (Z)-enol, and finally in favour of the (E)-configurated enol.
Chemical Consequences of Single-Electron Oxidation of Phenylmesityldiazoethane
Little, Charles B.,Schuster, Gary B.
, p. 7167 - 7175 (2007/10/02)
Both thermolysis and photolysis of 1-phenyl-2-mesityldiazoethane (PMDE) lead exclusively to products derived from facile hydrogen or mesityl migration subsequent to, or concurrent with, loss of N2.No detectable amounts of ketazine or any dimeric hydrocarbons are formed in these reactions -a result that is attributable to the steric hindrance about the diazo carbon in PMDE.Quite in contrast, the one-electron oxidation of this diazoalkane yields no monomeric products by simple hydrogen or mesityl migration; instead, ketazine and dimeric products are formed by two distinct paths.Dimerization of diazo radical cations followed by competing secondary reactions of the resulting dication is the favored path according for the major products.In a very much slower reaction, PMDE+. attacks neutral PMDE to yield ketazine.
New Methods and Reagents in Organic Synthesis. 20. 2-Mesitylenesulfonyl diazomethane: Synthesis and Application to the Arndt-Eistert Synthesis
Kuo, Ying-Che,Aoyama, Toyohiko,Shioiri, Takayuki
, p. 899 - 902 (2007/10/02)
2-Mesitylenesulfonyldiazomethane (4) was conveniently prepared from 2-mesitylenesulfonylchloride (5) in 4 steps.Reaction of 4 with benzoyl chloride smoothly furnished α-benzoyl α-(2-mesitylenesulfonyl)diazomethane (9).Thermal treatment of 9 in the presenc
The Chemistry of Aryllead(IV) Tricarboxylates. Reaction with Silyl Enol Ethers
Bell, Craig H.,Pinhey, John T.,Sternhell, Sever
, p. 2237 - 2245 (2007/10/02)
The trimethylsilyl enol ether of acetophenone (1) and p-methoxyphenyllead triacetate (2) react to give (p-methoxyphenyl)phenacyllead(IV) diacetate (4) in high yield.This plumbation reaction has been studied for a number of ketone trimethylsilyl enol ethers and aryllead triacetates, and it would appear that it is probably limited to aryl ketone trimethylsilyl enol ethers.The trifluoroacetic acid catalysed break down of these α-plumbated ketones to substituted deoxybenzoins has been examined in considerable detail.The thermal decomposition of one of the lead compounds to a deoxybenzoin derivative has also been examined.
