938-87-4Relevant academic research and scientific papers
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.
A Fast and General Route to Ketones from Amides and Organolithium Compounds under Aerobic Conditions: Synthetic and Mechanistic Aspects
Ghinato, Simone,Territo, Davide,Maranzana, Andrea,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
, p. 2868 - 2874 (2021/01/21)
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended.
Method for synthesizing aryl ketone compound by taking AQ as photocatalyst
-
Paragraph 0039-0043; 0076-0083, (2020/09/16)
The invention provides a method for synthesizing an aryl ketone compound by taking AQ as a photocatalyst. The method comprises the following steps that AQ serves as a photocatalyst; under the conditions of a palladium catalyst, a phosphine ligand, weak base and an organic solvent, a 390-to-430-nm photocatalysis lamp is used for irradiation at room temperature in an inert protective atmosphere, soan aldehyde group-containing compound reacts with Ar-X, wherein Ar-X is aryl halide or aryl trifluoromethanesulfonic acid, the aryl halide is aryl bromide or aryl iodide, and the aldehyde group-containing compound is one selected from aryl aldehyde, alkyl aldehyde, linear primary aldehyde and acyclic secondary aldehyde. According to the invention, the anthraquinone (AQ) HAT photocatalyst and palladium catalyst are combined for use, C-H arylation and alkenylation reactions of aldehyde can be directly carried out to synthesize ketone, and reaction efficiency is high. The method has the advantages of mild reaction conditions, high yield and a wide substrate application range, and can be used for synthesizing natural products in medicinal plants.
Direct C-H Arylation of Aldehydes by Merging Photocatalyzed Hydrogen Atom Transfer with Palladium Catalysis
Chen, Guangying,Cheng, Gui-Juan,Guo, Bin,Li, Xiaobao,Ran, Chongzhao,Wang, Lu,Wang, Ting,Wei, Jun-Jie,Zheng, Caijuan,Zheng, Chao
, p. 7543 - 7551 (2020/08/21)
Herein, we report that merging palladium catalysis with hydrogen atom transfer (HAT) photocatalysis enabled direct arylations and alkenylations of aldehyde C-H bonds, facilitating visible light-catalyzed construction of a variety of ketones. Tetrabutylammonium decatungstate and anthraquinone were found to act as synergistic HAT photocatalysts. Density functional theory calculations suggested a Pd0-PdII-PdIII-PdI-Pd0 pathway and revealed that regeneration of the Pd0 catalyst and the photocatalyst occurs simultaneously in the presence of KHCO3. This regeneration features a low energy barrier, promoting efficient coupling of the palladium catalytic cycle with the photocatalytic cycle. The work reported herein suggests great promise for further applications of HAT photocatalysis in palladium-catalyzed cross-coupling and C-H functionalization reactions to be successful.
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
-
Paragraph 0031-0032, (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.
Naphthyridine-based iridium complexes: Structures and catalytic activity on alkylation of aryl ketones
Chen, Po-Hao,Liu, Yi-Hung,Liu, Shiuh-Tzung
, p. 972 - 981 (2019/05/24)
Iridium(III) complexes containing a designed ligand, 2-amino-7-(2-pyridinyl)-1,8-naphthyridine derivative, were prepared and all complexes were characterized using spectroscopic and crystallographic methods. These new Ir(III) complexes are able to act as catalysts for the C-alkylation of aryl alkyl ketones with the use of alcohols as the alkylating agent. Typically, acetophenone undergoes alkylation with methanol and ethanol to yield isobutyrophenone and butyrophenone, respectively.
Palladacycle-Phosphine Catalyzed Methylation of Amines and Ketones Using Methanol
Mamidala, Ramesh,Biswal, Priyabrata,Subramani, M. Siva,Samser, Shaikh,Venkatasubbaiah, Krishnan
, p. 10472 - 10480 (2019/08/20)
Methylation of amines and ketones with palladacycle precatalyst has been performed using methanol as an environmentally benign reagent. Various ketones and amines undergo methylation reaction to yield monomethylated amines or ketones in moderate to good isolated yields. Moreover, this protocol was tested for the chemoselective methylation of 4-aminobenzenesulfonamide. The scope of the reaction was further extended to the deuteromethylation of ketones.
Catalytic C1 Alkylation with Methanol and Isotope-Labeled Methanol
Sklyaruk, Jan,Borghs, Jannik C.,El-Sepelgy, Osama,Rueping, Magnus
supporting information, p. 775 - 779 (2019/01/04)
A metal-catalyzed methylation process has been developed. By employing an air- and moisture-stable manganese catalyst together with isotopically labeled methanol, a series of D-, CD3-, and 13C-labeled products were obtained in good yields under mild reaction conditions with water as the only byproduct.
α-Methylation of Ketones with Methanol Catalyzed by Ni/SiO2-Al2O3
Charvieux, Aubin,Duguet, Nicolas,Métay, Estelle
supporting information, p. 3694 - 3698 (2019/06/13)
α-Methylation of ketones with methanol catalyzed by a cheap and easy to handle Ni/SiO2-Al2O3 was explored. After optimization of the reaction between propiophenone and methanol, the desired product was obtained in 95 % isolated yield. A wide range of ketones was methylated under the optimized conditions (16 examples). This procedure was extended to a three-component cross-benzylation-methylation of acetophenone.
