2431-96-1Relevant academic research and scientific papers
An Efficient Palladium-Catalysed Aminocarbonylation of Benzyl Chlorides
Oram, Niall,Richardson, Jeffery,Rilvin-Derrick, Eloise
, p. 369 - 372 (2020/02/27)
An improved procedure for the aminocarbonylation of benzyl chloride derivatives using carbon monoxide and either primary or secondary amines has been developed. Studying the competing background alkylation reaction allowed the solvent and base to be selected for a simple catalyst screen, which, in turn, enabled the discovery of a method for the preparation of 2-arylacetamides under mild conditions, with minimal side-products using an inexpensive phosphine ligand. This non-traditional optimisation strategy allowed us to overcome the background alkylation, which has been cited as justification for the development of more complex and less atom-economical approaches.
Synthesis of Novel Heterocycles by Amide Activation and Umpolung Cyclization
Maulide, Nuno,Riomet, Margaux,Roller, Alexander,Zhang, Haoqi
supporting information, (2020/03/24)
Herein, we report a metal-free synthesis of cyclic amidines, oxazines, and an oxazinone under mild conditions by electrophilic amide activation. This strategy features an unusual Umpolung cyclization mode and enables the smooth union of α-aryl amides and diverse alkylazides, effectively rerouting our previously reported α-amination transform.
Palladium-catalyzed carbonylation of benzylic ammonium salts to amides and esters: Via C-N bond activation
Yu, Weijie,Yang, Shuwu,Xiong, Fei,Fan, Tianxiang,Feng, Yan,Huang, Yuanyuan,Fu, Junkai,Wang, Tao
supporting information, p. 3099 - 3103 (2018/05/22)
An efficient palladium-catalyzed carbonylation reaction of readily available quaternary ammonium salts with CO is reported for the first time to afford arylacetamides and arylacetic acid esters via benzylic C-N bond cleavage. This protocol features mild reaction conditions under atmospheric pressure of CO, a redox-neutral process without an additional oxidant, and a broad substrate scope for various kinds of amines, alcohols and phenols.
Phototriggered Dehydration Condensation Using an Aminocyclopropenone
Mishiro, Kenji,Yushima, Yuki,Kunishima, Munetaka
supporting information, p. 4912 - 4915 (2017/09/23)
A phototriggered dehydration condensation using an aminocyclopropenone has been developed. The UV irradiation of an aminocyclopropenone generated a highly reactive ynamine in situ and the dehydration condensation of a carboxylic acid and an amine coexisting in the reaction solution smoothly proceeded to afford an amide. This reaction is completely controllable by the ON/OFF states of a UV lamp.
Sunlight assisted direct amide formation: Via a charge-transfer complex
Cohen, Irit,Mishra, Abhaya K.,Parvari, Galit,Edrei, Rachel,Dantus, Mauricio,Eichen, Yoav,Szpilman, Alex M.
supporting information, p. 10128 - 10131 (2017/09/23)
We report on the use of charge-transfer complexes between amines and carbon tetrachloride, as a novel way to activate the amine for photochemical reactions. This principle is demonstrated in a mild, transition metal free, visible light assisted, dealkylative amide formation from feedstock carboxylic acids and amines. The low absorption coefficient of the complex allows deep light penetration and thus scale up to a gram scale.
Mechanistic Pathways in Amide Activation: Flexible Synthesis of Oxazoles and Imidazoles
Di Mauro, Giovanni,Maryasin, Boris,Kaiser, Daniel,Shaaban, Saad,González, Leticia,Maulide, Nuno
supporting information, p. 3815 - 3818 (2017/07/26)
The preparation of substituted aminooxazoles and aminoimidazoles from α-arylamides and α-aminoamides through triflic anhydride-mediated amide activation is reported. These reactions proceed via the intermediacy of nitrilium adducts and feature N-oxide-promoted umpolung of the α-position of amides as well as a mechanistically intriguing sequence that results in sulfonyl migration from nitrogen to carbon. Quantum-chemical mechanistic analysis sheds light on the intricacies of the process.
Charge-Transfer Complex Promoted C-N Bond Activation for Ni-Catalyzed Carbonylation
Yu, Hui,Gao, Bao,Hu, Bin,Huang, Hanmin
supporting information, p. 3520 - 3523 (2017/07/17)
A new strategy was developed for activation of C-N bond via formation of an amine-I2 charge-transfer complex, which facilitates the inert C-N bond activation via oxidative addition with Ni(0). This strategy has been successfully applied in the Ni-catalyzed carbonylation of benzylamines via direct insertion of CO into the C-N bond, which provided a straightforward and rapid approach to arylacetamides in the presence of catalytic amounts of I2 and Ni catalyst. Mechanistic studies suggested that a benzyl radical generated via the oxidative addition was involved in the present reaction.
Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2
Li, Jing,Lear, Martin J.,Hayashi, Yujiro
supporting information, p. 9060 - 9064 (2016/07/26)
An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
Metal-Free Amidation of Acids with Formamides and T3P
Bannwart, Linda,Abele, Stefan,Tortoioli, Simone
, p. 2069 - 2078 (2016/07/06)
A new, simple and metal-free method for the direct formation of dialkylamides from carboxylic acids employing N,N-dialkylformamides as amine source is described. The one-pot reaction is promoted by propylphosphonic anhydride (T3P) in the presence of 0.5 equivalents of HCl.
Synthesis of Unsymmetrical Diaryl Acetamides, Benzofurans, Benzophenones, and Xanthenes by Transition-Metal-Free Oxidative Cross-Coupling of sp3 and sp2 C-H Bonds
Rathore, Vandana,Sattar, Moh.,Kumar, Raushan,Kumar, Sangit
, p. 9206 - 9218 (2016/10/14)
A chemo- and regioselective intermolecular sp3 C-H and sp2 C-H coupling reaction for C-C bond formation is described to access unsymmetrical diaryl acetamides under TM-free conditions from sec- and tert-arylacetamides and nitroarenes using tert-butoxide base in DMSO at room temperature. The coupling partners with sensitive functionalities such as chloro, bromo, hydroxy, and cyano were also amenable to the developed reaction. Synthesized α-(2/4-nitroaryl) phenylacetamides have been transformed into biologically important benzofurans, xanthenes, diaryl indoles, and unsymmetrical benzophenones by novel routes without applying a transition metal. Overall, an economical, yet efficient, strategy has been devised to access unsymmetrical diarylacetamides with the possibility of their further elaboration into a variety of biologically important heterocycles. Mechanistic understanding suggests that the reaction proceeds by a nucleophilic addition of a phenylacetamide carbanion, which is generated in the presence of tert-butoxide base, to the para or ortho (if para is substituted) position of nitrobenzene. The formed α-(4-nitrocyclohexa-2,4-dien-1-yl) phenylacetamide anion intermediate oxidized by a basic solution of DMSO or atmospheric oxygen led to the desired sp3 C-H and sp2 C-H coupled α-(2/4-nitroaryl) phenylacetamides.
