- Acetyl nitrate mediated conversion of methyl ketones to diverse carboxylic acid derivatives
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The development of a novel acetyl nitrate mediated oxidative conversion of methyl ketones to carboxylic acid derivatives is described. By analogy to the haloform reaction and supported by experimental and computational investigation we propose a mechanism for this transformation.
- Bernard, Josephine,Capilato, Joseph N.,Hoy, Erik P.,Mattiucci, Joseph,Pellegrinelli, Peter J.,Perez, Lark J.,Philippi, Shane,Schnorbus, Logan
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p. 5298 - 5302
(2021/06/30)
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- A CO2-Catalyzed Transamidation Reaction
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Transamidation reactions are often mediated by reactive substrates in the presence of overstoichiometric activating reagents and/or transition metal catalysts. Here we report the use of CO2as a traceless catalyst: in the presence of catalytic amounts of CO2, transamidation reactions were accelerated with primary, secondary, and tertiary amide donors. Various amine nucleophiles including amino acid derivatives were tolerated, showcasing the utility of transamidation in peptide modification and polymer degradation (e.g., Nylon-6,6). In particular,N,O-dimethylhydroxyl amides (Weinreb amides) displayed a distinct reactivity in the CO2-catalyzed transamidation versus a N2atmosphere. Comparative Hammett studies and kinetic analysis were conducted to elucidate the catalytic activation mechanism of molecular CO2, which was supported by DFT calculations. We attributed the positive effect of CO2in the transamidation reaction to the stabilization of tetrahedral intermediates by covalent binding to the electrophilic CO2
- Yang, Yang,Liu, Jian,Kamounah, Fadhil S.,Ciancaleoni, Gianluca,Lee, Ji-Woong
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p. 16867 - 16881
(2021/11/18)
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- NaOTs-promoted transition metal-free C-N bond cleavage to form C-X (X = N, O, S) bonds
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Multifunctional transformation of amide C-N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution with mild conditions and a simple procedure for transformation of multiple amides.
- Chen, Wei,Liu, Sicheng,Liu, Tingting,Majeed, Irfan,Ye, Xiaojing,Zeng, Zhuo,Zhang, Yuqi,Zhu, Yulin
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supporting information
p. 8566 - 8571
(2021/10/20)
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- 5-Bromo-norborn-2-en-7-one derivatives as a carbon monoxide source for palladium catalyzed carbonylation reactions
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Norbornenone (5b), obtained from the reaction of 2,5-dimethyl-3,4-diphenylcyclopentadienone dimer (3) with bromomaleic anhydride (4b), provides an excellent base-triggered source of carbon monoxide for palladium-catalysed carbonylation reactions. Aminocarbonylation, ketoamide synthesis, and Suzuki-Miyaura reactions of aryl iodides carried out in a two-chamber reaction vessel gave good to excellent yields of carbonylated products.
- Payne, China M.,Cho, Kyulee,Larsen, David S.
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p. 30736 - 30740
(2019/10/19)
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- Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
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An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
- Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
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supporting information
p. 5098 - 5102
(2018/09/13)
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- Ligand- and Solvent-Tuned Chemoselective Carbonylation of Bromoaryl Triflates
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The palladium-catalyzed chemoselective carbonylation of bromoaryl triflates is reported. The selective C?Br bond versus C?OTf (OTf=triflate) bond functionalization can be remarkably tuned by the combination of the ligand [4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) vs. 1,1′-bis(diphenylphosphino)ferrocene (DPPF)] and the solvent (toluene vs. DMSO). The respective ligand and solvent effects are rationalized by DFT calculations. In contrast, the monodentate ligands BuPAd2 and tBu3P prefer the selective C?Br bond activation and are solvent insensitive.
- Shen, Chaoren,Wei, Zhihong,Jiao, Haijun,Wu, Xiao-Feng
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p. 13369 - 1337
(2017/09/06)
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- Radical-mediated divergent cyclization of benzamides toward perfluorinated or cyanated isoquinolinediones
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A simple and efficient copper-controlled divergent cyclization of benzamides, which leads to perfluorinated or cyanated isoquinolinediones, is developed. In the presence of AIBN, methacryloyl benzamides with perfluoroalkyl iodides undergo cascade radical addition/cyclization to afford perfluoroinated isoquinolinediones as the major product under metal-free conditions, whereas the use of CuI (10 mol%) is able to redirect the cyclization to yield isoquinolinediones bearing an α-cyano quaternary carbon center. The cyclization features controllable divergent synthesis and a broad substrate scope as well as highly practical reaction conditions, thereby making this strategy a highly attractive means to fluorinate or cyanate isoquinolinediones.
- Deng, You-Lin,Tang, Shi,Ding, Guo-Liang,Wang, Ming-Wei,Li, Jie,Li, Zeng-Zeng,Yuan, Li,Sheng, Rui-Long
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supporting information
p. 9348 - 9353
(2016/10/13)
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- N-heterocyclic carbene-catalyzed oxidative amidation of aldehydes with amines
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The N-heterocyclic carbene (NHC)-catalyzed oxidative amidation of aromatic aldehydes with amines in the presence of N-bromosuccinimide (NBS) as an oxidant has been developed for the synthesis of amides. This amidation strategy is tolerant to both the electronic and the steric nature of the aryl aldehydes employed. The present methodology was extended to chiral amino acid derivatives to generate the corresponding amides in good yields and excellent ee values (>98%).
- Alanthadka, Anitha,Maheswari, C. Uma
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supporting information
p. 1199 - 1203
(2015/04/22)
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- Metal free amide synthesis via carbon-carbon bond cleavage
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A metal-free oxidative coupling of methyl ketones and primary amines to amides has been developed. The reaction tolerates a variety of functional groups, and is operationally simple. The reaction is proposed to go through a radical pathway to form the triiodomethyl ketone intermediate and the amide is formed by the nucleophilic attack of amine on triiodomethyl ketone carbonyl.
- Zhu, Chunyin,Wei, Wei,Du, Peng,Wan, Xiaobing
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p. 9615 - 9620
(2015/01/09)
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- Fluorescent β-cyclodextrins modified by isomeric aminobenzamides: Synthesis, conformational analysis, and fluorescent behaviors
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Three isomeric fluorescent β-cyclodextrins bearing 2-, 3-, and 4-(2-aminoethyl)amino-N-butylbenzamide, respectively (1-3) have been synthesized. The conformations of these fluorescent CDs have been investigated by 2D NMR and induced circular dichromism. It is confirmed that the ortho isomer 1 takes a butyl-included conformation, while the other two isomers 2 and 3 display a phenyl-included conformation, respectively. The three fluorescent CDs 1-3 exhibited totally different self- and guest-inclusion fluorescence behavior. In the presence of adamantane carboxylate sodium (ADA) or deoxycholate sodium (DCA), the fluorescence intensity of 1 showed an enhancement over 1-fold, while 2 exhibited dramatic fluorescence quenching. Interestingly, the fluorescent responses of 3 toward two guests respectively were highly distinguishable. The fluorescence intensity of 3 only showed a slight increase upon the addition of ADA, but the addition of DCA led to a large decrease in fluorescence intensity. The investigations have been further carried out by 2D NMR, induced circular dichromism, fluorescence spectroscopy and molecular modeling to explore the relationships between the conformations and the fluorescence characteristics of CDs 1-3 in the absence and presence of guest molecules. On the basis of the above investigations, the origins for the different fluorescence behaviors have been proposed.
- Wang, Lei,Zhong, Cheng,Xue, Peng,Fu, Enqin
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experimental part
p. 4874 - 4883
(2011/08/04)
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- Oxidative amidation of aldehydes and alcohols with primary amines catalyzed by KI-TBHP
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Oxidative amidation of aldehydes and alcohols with amines to afford the corresponding amides in excellent yields and ee values over 98% is achieved by using a catalytic amount of KI in combination with TBHP as the external oxidant. This method avoids the use of expensive and/or air-sensitive reagents. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Rajender Reddy,Uma Maheswari,Venkateshwar,Lakshmi Kantam
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supporting information; experimental part
p. 3619 - 3622
(2009/05/07)
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- Aminolysis of 2,2,2-Trichloro-1-arylethanones in Aprotic Solvents
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The kinetics of the reaction of the title substrate with various alkylamines was studied in n-heptane, dichloromethane, dioxane, tetrahydrofuran, and acetonitrile.The reaction was third-order in amine when the solvent was n-heptane or dichloromethane.In the other solvents a second-order dependence on was observed.The fourth-order rate constants for the reaction of n-butylamine with various 2,2,2-trichloro-1-arylethanones in dichloromethane yielded a ρ value of 3.0.In all solvents the observed rate constans decreased with a temperature increase.Two mechanistic possibilities were suggested, the first one in solvents of low donicity, involving a T0 intermediate formed in a concerted process with the participation of an amine dimer; and the second one, a stepwise process in more basic solvents which takes place via a T+/- intermediate.Base-catalyzed collapse of the tetrahedral intermediates is the rate-determining step in both pathways.
- Druzian, Janice,Zucco, Cesar,Rezende, Marcos Caroli,Nome, Faruk
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p. 4767 - 4771
(2007/10/02)
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- Studies on the Sructure of Some Derivatives of 1,3-Thiazolidine-2-thione and Δ2-1,3-Thiazoline-2-thiol
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Two types of reactions have been observed for the ambident anion of 1,3-thiazolidine-2-thione: regioselective N-acylation and S-alkylation.The structures of the products, amides and thioethers, were determined by X-ray crystallographic analysis and by ass
- Fujita, Eiichi,Nagao, Yoshimitsu,Seno, Kaoru,Takao, Sachiko,Miyasaka, Tadayo,et al.
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p. 914 - 919
(2007/10/02)
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