55234-56-5Relevant academic research and scientific papers
Facile Synthesis of γ-Ketonitriles in Water via C(sp2)–H Activation of Aromatic Aldehydes over Cu?g-C3N4 under Visible-Light
Bhardiya, Smita R.,Rai, Ankita,Rai, Vijai K.,Sheshma, Harendra,Singh, Manorama,Verma, Fooleswar
, p. 5841 - 5846 (2020/09/21)
A facile C(sp2)–H activation of aldehyde under visible-light conditions using Cu?g-C3N4 as photocatalyst and water as solvent is reported. The envisaged method involves photocatalytic intermolecular Stetter reaction using
Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst: Applications and mechanism thereof
Balletti, Matteo,De Pedro Beato, Eduardo,Mazzarella, Daniele,Melchiorre, Paolo
, p. 6312 - 6324 (2020/08/24)
We detail a strategy that uses a commercially available nucleophilic organic catalyst to generate acyl and carbamoyl radicals upon activation of the corresponding chlorides and anhydrides via a nucleophilic acyl substitution path. The resulting nucleophilic radicals are then intercepted by a variety of electron-poor olefins in a Giese-type addition process. The chemistry requires low-energy photons (blue LEDs) to activate acyl and carbamoyl radical precursors, which, due to their high reduction potential, are not readily prone to redox-based activation mechanisms. To elucidate the key mechanistic aspects of this catalytic photochemical radical generation strategy, we used a combination of transient absorption spectroscopy investigations, electrochemical studies, quantum yield measurements, and the characterization of key intermediates. We identified a variety of off-the-cycle intermediates that engage in a light-regulated equilibrium with reactive radicals. These regulated equilibriums cooperate to control the overall concentrations of the radicals, contributing to the efficiency of the overall catalytic process and facilitating the turnover of the catalyst. This journal is
A Photochemical Organocatalytic Strategy for the α-Alkylation of Ketones by using Radicals
Goti, Giulio,Melchiorre, Paolo,O?eka, Maksim,Schweitzer-Chaput, Bertrand,Spinnato, Davide
supporting information, p. 9485 - 9490 (2020/04/09)
Reported herein is a visible-light-mediated radical approach to the α-alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2-based activation of alkyl halides and blue light irradiation. The resulting open-shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two-electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox-neutral nature of this process makes it compatible with a cinchona-based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α-alkylation of ketones.
Syntheses of Pyrroles, Pyridines, and Ketonitriles via Catalytic Carbopalladation of Dinitriles
Qi, Linjun,Li, Renhao,Yao, Xinrong,Zhen, Qianqian,Ye, Pengqing,Shao, Yinlin,Chen, Jiuxi
, p. 1097 - 1108 (2020/01/22)
The first example of the Pd-catalyzed addition of organoboron reagents to dinitriles, as an efficient means of preparing 2,5-diarylpyrroles and 2,6-diarylpyridines, has been discussed here. Furthermore, the highly selective carbopalladation of dinitriles with organoboron reagents to give long-chain ketonitriles has been developed as well. Based on the broad scope of substrates, excellent functional group tolerance, and use of commercially available substrates, the Pd-catalyzed addition reaction of arylboronic acid and dinitriles is expected to be significant in future synthetic procedures.
A Novel Ketonitrile Synthesis by Palladium-Catalyzed Carbonylative Coupling Reactions of Amides with Arylboronic Acids
Mai, Wen-Peng,Liu, Yang,Sui, Hong-Dai,Xiao, Yong-Mei,Mao, Pu,Lu, Kui
supporting information, p. 7814 - 7819 (2019/12/24)
A novel, efficient, and simple procedure to synthesize diverse ketonitriles by palladium-catalyzed Suzuki coupling of amides through N–C cleavage has been developed. This procedure features mild conditions, a broad substrate scope, and easily prepared substrates, providing a simple and efficient access to a variety of ketonitriles.
Ag2CO3-mediated direct functionalization of alkyl nitriles: Facile synthesis of γ-ketonitriles through nitrile alkylation of enol acetates
Cheng, Pi,Wang, Wei,Wang, Lin,Zeng, Jianguo,Reiser, Oliver,Liang, Yun
, p. 1408 - 1412 (2019/05/06)
Direct C(sp3)-H functionalization of alkyl nitriles is a low toxic and facile route to nitrile-containing compounds. In this research, the Ag2CO3-mediated nitrile methylenation of enol acetates is developed to prepare γ-ketonitriles through the direct C(sp3)-H oxidative functionalization of acetonitrile. A radical pathway is proposed, and acetonitrile serves both as solvent and CN-containing radical source.
Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of ?-Diketones and ?-Ketonitriles
Li, Yi,Shang, Jia-Qi,Wang, Xiang-Xiang,Xia, Wen-Jin,Yang, Tao,Xin, Yangchun,Li, Ya-Min
supporting information, p. 2227 - 2230 (2019/03/26)
A novel copper-catalyzed decarboxylative oxyalkylation of alkynyl carboxylic acids with ketones and alkylnitriles via direct C(sp3)-H bond functionalization to construct new C-C bonds and C-O double bonds was developed. This transformation is featured by wide functional group compatibility and the use of readily available reagents, thus affording a general approach to ?-diketones and ?-ketonitriles. A possible mechanism is proposed.
Chemoselective Access to γ-Ketoesters with Stereogenic Quaternary α-Center or γ-Keto Nitriles by Aerobic Reaction of α-Cyanoesters and Styrenes
Zhang, Song-Lin,Wang, Xian-Jin,Yu, Ze-Long
supporting information, p. 3139 - 3142 (2017/06/23)
Chemoselective access to either γ-ketoesters with a quaternary all-carbon α-stereogenic center or γ-keto nitriles is described by copper-catalyzed aerobic reaction of styrenes with α-cyanoesters. Formal oxo-enolation or oxo-cyanomethylation of styrenes is achieved via a sequence of addition of enolate (or cyanomethyl) radical to olefin and oxidation of the resulting radical adduct. This method starts from abundant and cheap feedstock under aerobic conditions, without any prefunctionalization or the production of stoichiometric metal salts waste, making it very attractive for practical use.
Preparation γ - par phenyle and γ - ketoester method (by machine translation)
-
Paragraph 0089-0093, (2018/04/01)
The invention relates to a process for preparing γ - par phenyle and γ - ketoester method, characterized in that comprises the following experimental procedure: catalyst/ligand/additive under the catalytic action of, in the environment of oxygen, with the α - cyano ester substituted styrene mixed solution for 60 - 100 °C oil bath pot reaction 12 - 20 h; cooling after reaction to the room temperature, by extraction, washing, drying and chromatography, to obtain the product γ - par phenyle and γ - ketoester. The invention of each reaction raw material, catalyst, ligand, additive and solvent are industrial commodities, simple and easy to obtain, the price is cheap, and performance is quite stable, does not need special storage conditions, the operation is convenient. The invention has advantages of low cost, high yield, the process is simple, and less pollution and the like. (by machine translation)
Light-Driven Vitamin B12-Catalysed Generation of Acyl Radicals from 2-S-Pyridyl Thioesters
Ociepa, Micha?,Baka, Oskar,Narodowiec, Jakub,Gryko, Dorota
supporting information, p. 3560 - 3565 (2017/10/24)
Acyl radicals are invaluable intermediates in organic synthesis, however their generation remains challenging. Herein, we present an unprecedented light-driven, cobalt-catalysed method for the generation of acyl radicals from readily available 2-S-pyridyl thioesters. The synthetic potential of this methodology was demonstrated in the Giese-type acylation of activated olefins in the presence of heptamethyl cobyrrinate. This vitamin B12 derivative proved to be the most efficient catalyst in the studied process. The developed method features broad substrate scope (38 examples), good functional group tolerance, and mild reaction conditions. Moreover, it is easily scalable (illustrated on a 20-fold scale-up procedure), enabling its preparative use. Mechanistic studies revealed that the reaction proceeds via a radical pathway with the key steps involving the formation of an acyl-vitamin B12 complex and subsequent photolysis of the Co?C bond. (Figure presented.).
