2040-20-2Relevant academic research and scientific papers
Temperature Dependence of the Photochemistry of Aryl Alkyl Ketones
Encina, M. V.,Lissi, E. A.,Lemp, Else,Zanocco, A.,Scaiano, J. C.
, p. 1856 - 1860 (1983)
The photochemistry of several phenyl alkyl and p-anisyl alkyl ketones has been examined using laser flash photolysis and conventional quantum yield techniques.The methoxy-substituted ketones show higher activation energies (ΔEa ca. 3 kcal mol-1) for the Norrish type I and type II processes.It is concluded that both reactions are adiabatic processes occurring from the triplet n? surface.In the case of p-methoxy-substituted ketones the upper n? surface is reached from the low-lying ?? triplet, with the energy gap between both states reflected as an increase in the activation energy.
Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
Biswal, Priyabrata,Samser, Shaikh,Meher, Sushanta Kumar,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
, p. 413 - 419 (2021/11/01)
One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.
Rhenium(I)-Catalyzed C-Methylation of Ketones, Indoles, and Arylacetonitriles Using Methanol
Shee, Sujan,Kundu, Sabuj
, p. 6943 - 6951 (2021/05/29)
A ReCl(CO)5/MeC(CH2PPh2)3 (L2) system was developed for the C-methylation reactions utilizing methanol and base, following the borrowing hydrogen strategy. Diverse ketones, indoles, and arylacetonitriles underwent mono-and dimethylation selectively up to 99% yield. Remarkably, tandem multiple methylations were also achieved by employing this catalytic system.
1,3-Alkyl Transposition in Allylic Alcohols Enabled by Proton-Coupled Electron Transfer
Knowles, Robert R.,Seidler, Gesa,Zhao, Kuo
supporting information, p. 20190 - 20195 (2021/08/13)
A method is described for the isomerization of acyclic allylic alcohols into β-functionalized ketones via 1,3-alkyl transposition. This reaction proceeds via light-driven proton-coupled electron transfer (PCET) activation of the O?H bond in the allylic al
Experimental and Computational Studies of Palladium-Catalyzed Spirocyclization via a Narasaka-Heck/C(sp3or sp2)-H Activation Cascade Reaction
Wei, Wan-Xu,Li, Yuke,Wen, Ya-Ting,Li, Ming,Li, Xue-Song,Wang, Cui-Tian,Liu, Hong-Chao,Xia, Yu,Zhang, Bo-Sheng,Jiao, Rui-Qiang,Liang, Yong-Min
supporting information, p. 7868 - 7875 (2021/05/27)
The first synthesis of highly strained spirocyclobutane-pyrrolines via a palladium-catalyzed tandem Narasaka-Heck/C(sp3 or sp2)-H activation reaction is reported here. The key step in this transformation is the activation of a δ-C-H bond via an in situ generated σ-alkyl-Pd(II) species to form a five-membered spiro-palladacycle intermediate. The concerted metalation-deprotonation (CMD) process, rate-determining step, and energy barrier of the entire reaction were explored by density functional theory (DFT) calculations. Moreover, a series of control experiments was conducted to probe the rate-determining step and reversibility of the C(sp3)-H activation step.
Facile preparation of 5-alkyl-1-aryltetrazoles with arenes, acyl chlorides, hydroxylamine, and diphenylphosphoryl azide
Shibasaki, Kaho,Togo, Hideo
, p. 1816 - 1830 (2020/11/19)
Successive treatment of arenes with acyl chlorides and AlCl3, the addition of water and removal of solvent, the reaction with NH2OH?HCl and K2CO3, and the reaction with diphenylphosphoryl azide and DBU under warming conditions gave the corresponding 5-alkyl-1-aryltetrazoles efficiently in good to moderate yields. The present method is one-pot transformation of arenes into 5-alkyl-1-aryltetrazoles using the Friedel-Crafts acylation and the Beckmann rearrangement under transition-metal-free conditions.
Iron-Catalyzed Cleavage Reaction of Keto Acids with Aliphatic Aldehydes for the Synthesis of Ketones and Ketone Esters
Zhou, Fangyuan,Li, Lesong,Lin, Kao,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
supporting information, p. 4246 - 4250 (2020/03/11)
The radical–radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical–radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy.
Method for preparing aryl ketone based on iron-catalyzed free radical-free radical coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation
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Paragraph 0055-0056, (2020/05/05)
The invention discloses a method for preparing an aryl ketone derivative based on a free radical-free radical cross-coupling reaction such as ketonic acid decarboxylation and fatty aldehyde de-carbonylation. The method comprises the following steps: reacting aryl-substituted ketonic acid with fatty aldehyde under the catalytic action of ferric triacetylacetonate to generate an aryl ketone derivative; the gram-grade reaction can be realized by the method only by using 3mol% of an iron catalyst; and the method has the advantages of no need of consumption of a large amount of a Lewis acid catalyst or a stoichiometric organic metal reagent, mild reaction conditions, one-step reaction, few by-products, wide substrate application range and scalable reaction, and overcomes the defects of large catalyst consumption, insufficient functional group tolerance, many by-products and the like in the prior art.
Electrochemical [4+2] Annulation-Rearrangement-Aromatization of Styrenes: Synthesis of Naphthalene Derivatives
Ma, Yueyue,Lv, Jufeng,Liu, Chengyu,Yao, Xiantong,Yan, Guoming,Yu, Wei,Ye, Jinxing
supporting information, p. 6756 - 6760 (2019/04/17)
We report the first electrochemical strategy to synthesize functionalized naphthalene derivatives through [4+2] annulation—rearrangement–aromatization from styrenes under mild conditions. The electrolysis does not require metals, oxidants and high valence substrates, indicating the atom and step-economy ideals. The dehydrodimer produced through [4+2] cycloaddition of 4-methoxy α-methyl styrene is isolated and proved to be the key intermediate for the following oxydehydrogenation to form carbon cation, which undergoes rearrangement–aromatization to afford the final products. This reaction represents a powerful access to construct multi-substituted naphthalene blocks in a single step.
Organic Superbase t-Bu-P4 Catalyzes Amination of Methoxy(hetero)arenes
Shigeno, Masanori,Hayashi, Kazutoshi,Nozawa-Kumada, Kanako,Kondo, Yoshinori
supporting information, p. 5505 - 5508 (2019/08/01)
We report that the organic superbase t-Bu-P4 efficiently catalyzes the amination of methoxy(hetero)arenes with amine nucleophiles such as aniline, indoline, and aminopyridine derivatives. This catalytic reaction is effective for the transformation of elec
