1173294-91-1Relevant academic research and scientific papers
Acylation of Arenes with Aldehydes through Dual C-H Activations by Merging Photocatalysis and Palladium Catalysis
Wang, Haiyang,Li, Tao,Hu, Dongyan,Tong, Xiaogang,Zheng, Liyan,Xia, Chengfeng
supporting information, p. 3772 - 3776 (2021/05/10)
An acylation of arenes with aldehydes through dual C-H activations at room temperature is reported. The acylation was initiated by phenanthraquinone-catalyzed hydrogen atom transfer from aldehyde under visible light irradiation. The aldehyde-derived acyl
A Strategy for Amide C-N Bond Activation with Ruthenium Catalyst: Selective Aromatic Acylation
Li, Wenkuan,Zhang, Sheng,Feng, Xiujuan,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
supporting information, p. 2521 - 2526 (2021/04/05)
A strategy for amide C-N bond activation with ruthenium catalyst is described for the first time. The in situ formed bis-cycloruthenated complexes were demonstrated to be the key active species with superior oxidative addition ability to an inert amide C-N bond. The direct C-H bond activation of 2-arylpyridines followed by the amide C-N bond activation took place in the presence of a ruthenium precatalyst to produce monoacylation products in moderate to good yields. Synthetically useful functional groups, such as halogen atoms (F and Cl), ester, acetyl, and vinyl, remained intact during tandem C-H/C-N bond activation reactions.
Dual photoredox/palladium-catalyzed C-H acylation of 2-arylpyridines with oxime esters
He, Bin-Qing,Gao, Yuan,Wang, Peng-Zi,Wu, Hong,Zhou, Hong-Bin,Liu, Xiao-Peng,Chen, Jia-Rong
, p. 373 - 377 (2020/09/11)
An unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C-C bond cleavage and directed ortho C-H acylation of 2-arylpyridines by using oxime esters is described. Oxime esters can serve as efficient acyl sources through formation of the corresponding acyl radicals by photoredox-catalyzed iminyl-radical-mediated C-C bond cleavage. This redox-neutral protocol features excellent regioselectivity, a broad substrate scope, and good functional-group tolerance with respect to both components, giving a broad range of aryl ketones with generally good yields.
Monodisperse CuPd alloy nanoparticles as efficient and reusable catalyst for the C (sp2)–H bond activation
Huang, Fei,Wang, Feifan,Hu, Qiyan,Tang, Lin,Xu, Dongping,Fang, Yang,Zhang, Wu
, (2021/03/17)
Metal-catalyzed selective activation of C–H bonds is very important for the construction of a variety of biologically active molecules. Supported alloy nanoparticles are of great interest in various catalytic applications due to the synergistic effects between different metals. Here, well-dispersed CuPd alloy nanoparticles supported on reduced graphene oxide (rGO) were synthesized and found to be highly efficient and recyclable catalyst for the chelation-assisted C (sp2)–H bond activation. Aromatic ketones or esters were synthesized via the cross-dehydrogenative coupling (CDC) reaction between 2-arylpyridines and alcohols or acids. Moreover, the catalyst was recovered and used for five times without significantly losing activity.
Silver catalyzed pyridine-directed acceptorless dehydrogenation of secondary alcohols
Zhuang, Xin,Tao, Jing,Luo, Zhen,Hong, Chuan-Ming,Liu, Zheng-Qiang,Li, Qing-Hua,Ren, Li-Qing,Luo, Qun-Li,Liu, Tang-Lin
, p. 245 - 249 (2021/02/03)
A silver catalyzed pyridine-directed acceptorless dehydrogenation of secondary benzyl alcohols was developed. This general procedure delivers ketones with high atom-economy and hydrogen was the sole byproduct. This dehydrogenation reaction has a good functional group tolerance and high efficiency (up to 90% yield and 10,000/1 substrates-to-catalyst ratio).
Ruthenium-Catalyzed Carbonylative Coupling of Anilines with Organoboranes by the Cleavage of Neutral Aryl C-N Bond
Xu, Jian-Xing,Zhao, Fengqian,Yuan, Yang,Wu, Xiao-Feng
, p. 2756 - 2760 (2020/03/30)
Herein, we report the first ruthenium-catalyzed Suzuki-type carbonylative reaction of electronically neutral anilines via C(aryl)-N bond cleavage. Without any ligand and base, diaryl ketones can be obtained in moderate to high yields by using Ru3/su
Nickel-catalyzed regioselective C-H acylation of chelating arenes: A new catalytic system for C-C bond formation: Via a radical process and its mechanistic explorations
Li, Ze-Lin,Wu, Peng-Yu,Sun, Kang-Kang,Cai, Chun
, p. 12152 - 12158 (2019/08/07)
An unprecedented acylation at the ortho C-H bond of chelating arenes via the Ni(ii)-catalyzed cross dehydrogenative coupling strategy has been developed here. This new procedure exhibits excellent regioselectivity and good functional group tolerance. This discovery could be of great importance for the C-H acylation reactions of chelating arenes without any extraneous directing group and for the application of nickel-catalyzed C-H activation. Mechanistic investigations into the reaction process are also described.
Ag1Pd1-rGO nanocomposite as recyclable catalyst for CDC reactions of 2-arylpyridines with aldehydes
Hu, Qiyan,Liu, Xiaowang,Huang, Fei,Wang, Feifan,Li, Qian,Zhang, Wu
, p. 27 - 31 (2018/05/29)
Ag1Pd1 nanoparticle-reduced graphene oxide (Ag1Pd1-rGO) nanocomposite was used as an efficient catalyst for the synthesis of aromatic ketones via cross dehydrogenative coupling (CDC) reactions of 2-arylpyridines
Use of Cyclopropane as C1 Synthetic Unit by Directed Retro-Cyclopropanation with Ethylene Release
Asako, Sobi,Kobashi, Takaaki,Takai, Kazuhiko
supporting information, p. 15425 - 15429 (2018/11/23)
Cyclopropanation of alkenes is a well-established textbook reaction for the synthesis of cyclopropanes, where a "high-energy" carbene species is exploited to drive the reaction forward. However, little attention has been focused toward molecular transformations involving the reverse reaction, retro-cyclopropanation (RC). This is because of difficulties associated with both cleaving the two geminal C-C single bonds and exploiting the generated carbenes for further transformations in an efficient and selective manner. Here, we report that a molybdenum-based catalytic system overcomes the above challenges and effects the RC of cyclopropanes bearing a pyridyl group with the release of ethylene (alkene) and the subsequent intramolecular cyclization leading to pyrido[2,1-a]isoindoles. The reaction allows for the uncommon use of cyclopropanes as C1 synthetic units in contrast to most conventional reactions in which cyclopropanes are used as C3 synthetic units. We anticipate that this new strategy will pave the way for C1 cyclopropane chemistry.
Palladium-catalyzed decarboxylative, decarbonylative and dehydrogenative C(sp2)-H acylation at room temperature
Hossian, Asik,Manna, Manash Kumar,Manna, Kartic,Jana, Ranjan
supporting information, p. 6592 - 6603 (2017/08/16)
Over the past few decades, an impressive array of C-H activation methodology has been developed for organic synthesis. However, due to the inherent inertness of the C-H bonds (e.g. ~110 kcal mol-1 for the cleavage of C(aryl)-H bonds) harsh reaction conditions have been realized to overcome high energetic transition states resulting in a limited substrate scope and functional group tolerance. Therefore, the development of mild C-H functionalization protocols is in high demand to exploit the full potential of the C-H activation strategy in the synthesis of a complex molecular framework. Although, electron-rich substrates undergo electrophilic metalation under relatively mild conditions, electron-deficient substrates proceed through a rate-limiting C-H insertion under forcing conditions at high temperature. In addition, a stoichiometric amount of toxic silver salt is frequently used in palladium catalysis to facilitate the C-H activation process which is not acceptable from the environmental and industrial standpoint. We report herein, a Pd(ii)-catalyzed decarboxylative C-H acylation of 2-arylpyridines with α-ketocarboxylic acids under mild conditions. The present protocol does not require stoichiometric silver(i) salts as additives and proceeds smoothly at ambient temperature. A novel decarbonylative C-H acylation reaction has also been accomplished using aryl glyoxals as acyl surrogates. Finally, a practical C-H acylation via a dehydrogenative pathway has been demonstrated using commercially available benzaldehydes and aqueous hydroperoxides. We also disclose that acetonitrile solvent is optimal for the acylation reaction at room temperature and has a prominent role in the reaction outcome. Control experiments suggest that the acylation reaction via decarboxylative, decarbonylative and dehydrogenative proceeds through a radical pathway. Thus we disclose a practical protocol for the sp2 C-H acylation reaction.
