- Metal-free hydroalkoxylation of ynesulfonamides with esters
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An efficient metal-free hydroalkoxylation reaction of ynesulfonamides with esters under mild conditions is described. Under the catalysis of TMSOTf, various ynesulfonamides are transformed into the corresponding alkoxy-substituted enamides in high yields
- Gao, Erhui,Peng, Cheng,Zhang, Jingyi,Wang, Xiao-Na,Chang, Junbiao
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supporting information
p. 2182 - 2185
(2021/03/26)
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- Catalyst-Free, Metal-Free, and Chemoselective Transamidation of Activated Secondary Amides
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A simple protocol, which is catalyst-free, metal-free, and chemoselective, for transamidation of activated secondary amides in ethanol as solvent under mild conditions is reported. A wide range of amines, amino acids, amino alcohols, and the substituents, which are problematic in catalyzed transamidation, are tolerated in this methodology. The transamidation reaction was successfully extended to water as the medium as well. The present methodology appears to be better than the other catalyzed transamidations reported recently.
- Ramkumar, Rajagopal,Chandrasekaran, Srinivasan
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p. 921 - 932
(2019/02/10)
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- Efficient N-acylation of sulfonamides using cesium salt of Wells–Dawson heteropolyacid as catalyst: Synthesis of new N-acyl sulfonamides and cyclic imides
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N-acylation of substituted sulfonamides with different anhydrides in the presence of Cesium salt of Wells–Dawson heteropolyacid (Cs5HP2W18O62) as an efficient and reusable catalyst was investigated for the first time. ?Cs5HP2W18O62 was used with a catalytic amount in water as a green solvent. At room temperature, a series of N-acylsulfonamides were synthesized, while under refluxing conditions, new cyclic imides containing sulfonyl group were obtained. Atom-economy, high yields, easy work-up, as well as simple catalyst recovery and reusability are the key features of this procedure.
- Benali, Nesma,Bougheloum, Chafika,Alioua, Sabrina,Belghiche, Robila,Messalhi, Abdelrani
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p. 3099 - 3112
(2018/12/04)
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- Metal-free hydroacyloxylation and hydration reactions of ynamides: Synthesis of α-acyloxyenamides and N-acylsulfonamides
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Two types of highly efficient and operationally simple reactions of ynamides under metal-free conditions are developed, including hydroacyloxylation and hydration, which afforded highly functionalized α-acyloxyenamides and pharmaceutically important N-acy
- Xu, Shijie,Liu, Jianquan,Hu, B. Donghua,Bi, Xihe
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supporting information
p. 184 - 187
(2018/04/16)
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- Transition-metal-free tunable chemoselective nfunctionalization of indoles with ynamides
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Two unprecedented Nfunctionalizations of indoles with ynamides are described. By varying the electron-withdrawing group on the ynamide nitrogen atom, either Z-indolo-etheneamides or indolo-amidines can be selectively obtained under the same metal-free reaction conditions. The scope and synthetic potential of these reactions, as well as some mechanistic insights provided by DFT calculations, are reported.
- Hentz, Alexandre,Retailleau, Pascal,Gandon, Vincent,Cariou, Kevin,Dodd, Robert H.
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supporting information
p. 8333 - 8337
(2014/08/18)
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- N -acyl DBN tetraphenylborate salts as N -acylating agents
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Air-stable and crystalline N-acyl DBN tetraphenylborate salts have been synthesized from 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) and the corresponding acyl chloride in the presence of sodium tetraphenylborate. The salts have been shown to be effective N-acylating agents, reacting with primary amines, secondary amines, and sulfonamides to form the corresponding N-acylated products in good yields. The DBN hydrotetraphenylborate byproduct can be conveniently removed by filtration, providing pure N-acylated products without the need for further purification. The N-acyl DBN tetraphenylborate salts are attractive alternatives to acyl halides as they can be stored in air without decomposition, avoid the production of free acid during acylation reactions, and can be used under more forcing thermal conditions.
- Taylor, James E.,Jones, Matthew D.,Williams, Jonathan M. J.,Bull, Steven D.
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experimental part
p. 2808 - 2818
(2012/04/23)
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- A new and efficient method for the facile synthesis of N-acyl sulfonamides under Lewis acid catalysis
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The N-acylation of sulfonamides with carboxylic acid anhydrides in the presence of Lewis acids is described. Several Lewis acids such as BF3·Et2O, ZnCl2, MoCl5, TiCl4, B(C6F5)su
- Raji Reddy, Chada,Mahipal, Bodugam,Yaragorla, Srinivasa Rao
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p. 7528 - 7532
(2008/03/14)
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- Reductive deprotection of allyl, benzyl and sulfonyl substituted alcohols, amines and amides using a naphthalene-catalysed lithiation
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The reaction of different protected alcohols, amines and amides with lithium and a catalytic amount of naphthalene (4 mol %) in THF at low temperature leads to their deprotection under very mild reaction conditions, the process being in many cases chemoselective.
- Alonso, Emma,Ramon, Diego J.,Yus, Miguel
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p. 14355 - 14368
(2007/10/03)
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- Chemical and Spectroscopical Evidence for an Electron-Transfer Mechanism in the Reaction of Arenesulfonyl Chlorides with Anions
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The reaction of amide and amidate anions 2 with p-toluenesulfonyl chloride (1) under different reaction conditions gives rise to the total or partial reduction of the acyl halide to p-toluenesulfinic acid (5) and acylation compounds in variable amounts depending on the crowding at the anionic center.This indicates that a Single-Electron Transfer (SET) mechanism is involved in the reactions of 1 with anions.Unpaired electron species are detected by ESR in the course of the reactions. - Key Words: Arene sulfonyl chlorides/ Electron transfer (ET) mechanism
- Asensio, Gregorio,Nunez, Elena Gonzalez,Rodrigo, Maria Jose,Varea, Teresa
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p. 1799 - 1802
(2007/10/02)
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