1536-23-8Relevant academic research and scientific papers
Aryl palladium carbene complexes and carbene-aryl coupling reactions
Albeniz, Ana C.,Espinet, Pablo,Manrique, Raul,Perez-Mateo, Alberto
, p. 1565 - 1573 (2005)
Transmetalation of an aminocarbene moiety from [W(CO) 5{C(NEt2)R}] to palladium leads to isolable monoaminocarbene palladium aryl complexes [{Pd(μ-Br)Pf[C(NEt 2)R]}2] (R = Me, Ph; Pf = C6F5). When [W(CO)5{C(OMe)R}] is used, the corresponding palladium carbenes cannot be isolated since these putative, more electrophilic carbenes undergo a fast migratory insertion process to give alkyl palladium complexes. These complexes could be stabilized in the η3-allylic form for R = 2-phenylethenyl or in the less stable η3-benzylic fashion for R = Ph. Hydrolysis products and a pentafluorophenylvinylic methyl ether (when R = Me) were also observed. The monoaminocarbenes slowly decompose through carbene-aryl coupling to produce the corresponding iminium salts and, depending on the reaction conditions, the corresponding hydrolysis products. The electrophilicity of the carbene carbon, which is mainly determined by the nature of the heteroatom group, controls the ease of evolution by carbene-aryl coupling. Accordingly, no carbene-aryl coupling was observed for a diaminocarbene palladium aryl complex.
London Dispersion Interactions Rather than Steric Hindrance Determine the Enantioselectivity of the Corey–Bakshi–Shibata Reduction
Eschmann, Christian,Song, Lijuan,Schreiner, Peter R.
supporting information, p. 4823 - 4832 (2021/02/01)
The well-known Corey–Bakshi–Shibata (CBS) reduction is a powerful method for the asymmetric synthesis of alcohols from prochiral ketones, often featuring high yields and excellent selectivities. While steric repulsion has been regarded as the key director of the observed high enantioselectivity for many years, we show that London dispersion (LD) interactions are at least as important for enantiodiscrimination. We exemplify this through a combination of detailed computational and experimental studies for a series of modified CBS catalysts equipped with dispersion energy donors (DEDs) in the catalysts and the substrates. Our results demonstrate that attractive LD interactions between the catalyst and the substrate, rather than steric repulsion, determine the selectivity. As a key outcome of our study, we were able to improve the catalyst design for some challenging CBS reductions.
A Bifunctional Iron Nanocomposite Catalyst for Efficient Oxidation of Alkenes to Ketones and 1,2-Diketones
Ma, Zhiming,Ren, Peng,Song, Tao,Xiao, Jianliang,Yang, Yong,Yuan, Youzhu
, p. 4617 - 4629 (2020/05/19)
We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe-Nx and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe-N-C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.
Decarboxylative Cross-Coupling of Acyl Fluorides with Potassium Perfluorobenzoates
Fu, Liyan,Chen, Qiang,Nishihara, Yasushi
supporting information, p. 6388 - 6393 (2020/08/24)
We report the transition metal-free decarboxylative cross-coupling reactions of acyl fluorides with potassium perfluorobenzoates. Compared with traditional transition metal-catalyzed cross-couplings, this protocol presents an extremely environmentally ben
Pd(II)-Catalyzed Denitrogenative and Desulfinative Addition of Arylsulfonyl Hydrazides with Nitriles
Meng, Mengting,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
, p. 3275 - 3284 (2018/03/25)
A Pd(II)-catalyzed denitrogenative and desulfinative addition of arylsulfonyl hydrazides with nitriles has been successfully achieved under mild conditions. This transformation is a new method for the addition reaction to nitriles with arylsulfonyl hydrazides as arylating agent, thus providing an alternative synthesis of aryl ketones. The reported addition reaction is tolerant to many common functional groups, and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported denitrogenative and desulfinative addition was also appropriate for alkyl nitriles, making this newly developed transformation attractive.
Preparation method of aromatic ketone
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Paragraph 0046; 0047; 0048; 0050, (2018/09/11)
The invention discloses a preparation method of aromatic ketone. Under the effects of a palladium catalyst and a nitrogen-containing ligand, nitrile compounds and arylsulfonylhydrazide take desulfurization addition reaction in an organic solvent; after the reaction is completed, post treatment is performed to obtain aromatic ketone. The reaction is applicable to aromatic nitrile compounds, and isalso applicable to aliphatic nitrile compounds; the reaction realizes the wide substrate applicability and functional group tolerance; the potential application value is realized in the aspect of aryl-carbonyl building.
Method for preparing aromatic ketone in aqueous phase
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Paragraph 0042-0045, (2018/04/26)
The invention discloses a method for preparing aromatic ketone in an aqueous phase, comprising the following steps: enabling aryl formyl potassium formate and aryl potassium fluoborate to generate decarboxylation acylation reaction in water under the actions of a silver catalyst and an oxidizing agent, and performing treatment after reaction is ended to obtain the disclosed aromatic ketone. According to the preparation method, the silver catalyst replaces a noble metal catalyst, water is taken as a solvent, an aromatic ketone product is obtained with relatively high yield, the adopted catalystis low in cost and easy to obtain, reaction conditions are mild, and meanwhile, the product is good in university, and therefore, the method has good application potential.
Ag(i)/persulfate-catalyzed decarboxylative coupling of α-oxocarboxylates with organotrifluoroborates in water under room temperature
Chang, Sheng,Wang, Jian Feng,Dong, Lin Lin,Wang, Dan,Feng, Bo,Shi, Yuan Tai
, p. 51928 - 51934 (2017/11/22)
The decarboxylative coupling reaction of α-oxocarboxylates and organotrifluoroborates was carried out smoothly in the presence of catalytic AgNO3 using K2S2O8 as oxidant to generate diarylketone products in high
Carbonylative coupling of aryl tosylates/triflates with arylboronic acids under CO atmosphere
Hao, Cheng Yi,Wang, Dan,Li, Ya Wei,Dong, Lin Lin,Jin, Ying,Zhang, Xiu Rong,Zhu, He Yun,Chang, Sheng
, p. 86502 - 86509 (2016/09/23)
The carbonylative Suzuki-Miyaura reaction between aryl tosylates/triflates with arylboronic acid is herein reported, using base-free conditions and a balloon pressure of carbon monoxide. Under these conditions, unsymmetrical biaryl ketones were obtained in modest to excellent yields. This method was adapted to the synthesis of oxybenzone and ketoprofen in good yields under mild conditions.
Carbonylative Hiyama coupling of aryl halides with arylsilanes under balloon pressure of CO
Chang, Sheng,Jin, Ying,Zhang, Xiu Rong,Sun, Yong Bing
supporting information, p. 2017 - 2020 (2016/04/26)
An efficient protocol has been developed for the carbonylative Hiyama coupling of aryl halides using the cesium fluoride as a promoter by palladium-catalyzed in NMP. This protocol was applied to a wide variety of functionalized and hindered aryl iodides and bromides with arylsilanes, to afford the desired biaryl ketones in good to excellent yields.
