- Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
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A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
- Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
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supporting information
p. 4843 - 4848
(2021/06/28)
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- Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
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This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
- Brittain, William D. G.,Cobb, Steven L.
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p. 5793 - 5798
(2021/08/01)
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- Exploration of Cu-catalyzed regioselective hydrodehalogenation of o-haloanilides using EtOH as hydrogen source
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In present work, we have explored a Cu(acac)2/vasicine-catalyzed regioselective hydrodehalogenation methodology of o-haloanilides using EtOH as hydrogen source and solvent. The catalytic system could selectively dehalogenate 2-Br and 2-I, and features regioselective, efficient and functional group tolerance.
- Li, Min-Xin,Li, Mei-Ling,Tang, Yan-Ling,Sun, Yun,Qu, Lu,Huang, Feng,Mao, Ze-Wei
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supporting information
(2021/05/03)
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- Iron-catalyzed cross-coupling of N?methoxy amides and arylboronic acids for the synthesis of N-aryl amides
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An efficient iron-catalyzed synthesis of N-aryl amides from N?methoxy amides and arylboronic acids is developed. FeCl3 is used as the sole catalyst for the cross-coupling reaction between N?methoxy amides and arylboronic acids without any other
- Li, Jinhui,Liu, Jin-Biao,Luo, Nianhua,Qiu, Guanyinsheng,Ren, Shangfeng,Wang, Ying,Xie, Huilin
-
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- Acetonitrile and benzonitrile as versatile amino sources in copper-catalyzed mild electrochemical C-H amidation reactions
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A mild, efficient electrochemical approach to the site-selective direct C-H amidation of benzene and its derivatives with acetonitrile and benzonitrile has been developed. It has been shown that joint electrochemical oxidation of various arenes in the presence of a copper salt as a catalyst and nitriles leads to the formation of N-phenylacetamide from benzene and N-benzylacetamides from benzyl derivatives (up to 78% yield). A favorable feature of the process is mild conditions (room temperature, ambient pressure, no strong oxidants) that meet the criteria of green chemistry.
- Budnikova, Yulia,Kononov, Alexander,Rizvanov, Ildar,Strekalova, Sofia
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p. 37540 - 37543
(2021/12/07)
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- Visible-Light-Promoted Iron-Catalyzed N-Arylation of Dioxazolones with Arylboronic Acids
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A visible-light-promoted and simple iron salt-catalyzed N-arylation was achieved efficiently under external photosensitizer-free conditions. Arylboronic acids and bench-stable dioxazolones were used for this cross-coupling reaction. This reaction features high reactivity, wide substrate scope, good functional group tolerance, simple operation procedure, and mild reaction conditions. Preliminary mechanistic investigations were conducted to support a radical pathway. This method may contribute to shift the paradigm of iron-catalyzed C-N bond construction and nitrene transfer chemistry.
- Tang, Jing-Jing,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
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p. 13955 - 13961
(2021/11/20)
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- A practical and sustainable protocol for direct amidation of unactivated esters under transition-metal-free and solvent-free conditions
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In this paper, a NaOtBu-mediated synthesis approach was developed for direct amidation of unactivated esters with amines under transition-metal-free and solvent-free conditions, affording a series of amides in good to excellent yields at room temperature. In particular, an environmentally friendly and practical workup procedure, which circumvents the use of organic solvents and chromatography in most cases, was disclosed. Moreover, the gram-scale production of representative products3a,3wand3auwas efficiently realized by applying operationally simple, sustainable and practical procedures. Furthermore, this approach was also applicable to the synthesis of valuable molecules such as moclobemide (a powerful antidepressant), benodanil and fenfuram (two commercial agricultural fungicides). These results demonstrate that this protocol has the potential to streamline amide synthesis in industry. Meanwhile, quantitative green metrics of all the target products were evaluated, implying that the present protocol is advantageous over the reported ones in terms of environmental friendliness and sustainability. Finally, additional experiments and computational calculations were carried out to elucidate the mechanistic insight of this transformation, and one plausible mechanism was provided on the basis of these results and the related literature reports.
- Chen, Cheng,Cheng, Hua,Du, Min-Chen,Qian, Liang,Qin, Xin,Sang, Wei,Yao, Wei-Zhong,Yuan, Ye,Zhang, Rui
-
supporting information
p. 3972 - 3982
(2021/06/17)
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- Mechanochemical Synthesis of N-Aryl Amides from O-Protected Hydroxamic Acids
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Two robust and efficient mechanochemical protocols for the synthesis of an array of N-arylamides have been developed. This was achieved by a C?N cross-coupling between O-pivaloyl hydroxamic acids and aryl iodides or aryl boronic acids, in the presence of a stoichiometric amount of a copper mediator. The effectiveness of this method is highlighted by the high-yielding (up to 94 %), scalable (up to 8 mmol), and rapid (20 minutes) synthesis of N-aryl amides (15 examples), using a variety of deactivated and sterically encumbered substrates, whilst employing mild conditions and in the absence of solvents. In addition, it was determined that whilst the O-pivaloyl hydroxamic acid precursors can be synthesised mechanochemically, iron contamination originating from the steel jars was found to occur which can hinder the efficacy of this process. Furthermore, 3D printing was used to produce custom milling jars that could successfully accommodate a scaled-up version of the two protocols.
- Broumidis, Emmanouil,Jones, Mary C.,Lloyd, Gareth O.,Vilela, Filipe
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p. 1754 - 1761
(2020/09/02)
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- Rhodium-Catalyzed Addition of Organozinc Iodides to Carbon-11 Isocyanates
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Amides were prepared using rhodium-catalyzed coupling of organozinc iodides and carbon-11 (11C, t1/2 = 20.4 min) isocyanates. Nonradioactive isocyanates and sp3 or sp2 organozinc iodides generated amides in yields of 13%-87%. Incorporation of cyclotron-produced [11C]CO2 into 11C-amide products proceeded in yields of 5%-99%. The synthetic utility of the methodology was demonstrated through the isolation of [11C]N-(4-fluorophenyl)-4-methoxybenzamide ([11C]6g) with a molar activity of 267 GBq μmol-1 and 12% radiochemical yield in 21 min from the beginning of synthesis.
- Fouad, Moustafa H.,Ismailani, Uzair S.,Mair, Braeden A.,Munch, Maxime,Rotstein, Benjamin H.
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p. 2746 - 2750
(2020/04/16)
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- Nickel/briphos-catalyzed transamidation of unactivated tertiary amides
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The transamidation of tertiary amides was achieved via nickel catalysis in combination with briphos ligands. N-Methyl-N-phenylbenzamide derivatives reacted with primary amines in the presence of NiCl2/briphos L4 to provide the transamidated products in moderate to good yields. Primary aromatic amines delivered higher product yields than aliphatic amines.
- Kim, Hyunwoo,Lee, Sunwoo,Shin, Taeil,Yang, Dahyeon
-
supporting information
p. 6053 - 6057
(2020/10/27)
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- Buchwald-Hartwig cross-coupling of amides (transamidation) by selective N-C(O) cleavage mediated by air- And moisture-stable [Pd(NHC)(allyl)Cl] precatalysts: Catalyst evaluation and mechanism
-
The Pd-NHC-catalyzed acyl-type Buchwald-Hartwig cross-coupling of amides by N-C(O) cleavage (transamidation) provides a valuable alternative to the classical methods for amide synthesis. Herein, we report a combined experimental and computational study of the Buchwald-Hartwig cross-coupling of amides using well-defined, air- and moisture-stable [Pd(NHC)(allyl)Cl] precatalysts. Most crucially, we present a comprehensive evaluation of a series of distinct Pd(ii)-NHC precatalysts featuring different NHC scaffolds and throw-away ligands for the synthesis of functionalized amides that are not compatible with stoichiometric transition-metal-free transamidation methods. Furthermore, we present evaluation of the catalytic cycle by DFT methods for a series of different Pd(ii)-NHC precatalysts. The viability of accessing NHC-supported acyl-palladium(ii) amido complexes will have implications for the design and development of cross-coupling methods involving stable amide electrophiles.
- Li, Guangchen,Zhou, Tongliang,Poater, Albert,Cavallo, Luigi,Nolan, Steven P.,Szostak, Michal
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p. 710 - 716
(2020/02/25)
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- A Unified and Practical Method for Carbon–Heteroatom Cross-Coupling using Nickel/Photo Dual Catalysis
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While carbon–heteroatom cross-coupling reactions have been extensively studied, many methods are specific and limited to a particular set of substrates or functional groups. Reported here is a general method that allows for C?O, C?N and C?S cross-coupling reactions under one general set of conditions. We propose that an energy transfer pathway, in which an iridium photosensitizer produces an excited nickel(II) complex, is responsible for the key reductive elimination step that couples aryl bromides, iodides, and chlorides to 1° and 2° alcohols, amines, thiols, carbamates, and sulfonamides, and is amenable to scale up via a flow apparatus.
- Escobar, Randolph A.,Johannes, Jeffrey W.
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supporting information
(2020/04/17)
-
- Switching from biaryl formation to amidation with convoluted polymeric nickel catalysis
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A stable, reusable, and insoluble poly(4-vinyl-pyridine) nickel catalyst (P4VP-NiCl2) was prepared through the molecular convolution of poly(4-vinylpyridine) (P4VP) and nickel chloride. We proposed a coordination structure of the Ni center in the precatalyst based on elemental analysis and Ni K-edge XANES, and we confirmed that it is consistent with Ni K-edge EXAFS. The Suzuki?Miyaura-type coupling of aryl halides and arylboronic esters proceeded using P4VP-NiCl2 (0.1 mol % Ni) to give the corresponding biaryl compounds in up to 94% yield. Surprisingly, when the same reaction of aryl halides and arylboronic acid/ester was carried out in the presence of amides, the amidation proceeded predominantly to give the corresponding arylamides in up to 99% yield. In contrast, the reaction of aryl halides and amides in the absence of arylboronic acid/ester did not proceed. P4VP-NiCl2 successfully catalyzed the lactamization for preparing phenanthridinone. P4VP-NiCl2 was reused five times without significant loss of catalytic activity. Pharmaceuticals, natural products, and biologically active compounds were synthesized efficiently using P4VPNiCl2 catalysis. Nickel contamination in the prepared pharmaceutical compounds was not detected by ICP-MS analysis. The reaction was scaled to multigrams without any loss of chemical yield. Mechanistic studies for both Suzuki?Miyaura and amidation were performed.
- Sen, Abhijit,Dhital, Raghu N.,Sato, Takuma,Ohno, Aya,Yamada, Yoichi M.A.
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p. 14410 - 14418
(2020/12/21)
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- Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
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Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
- Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
-
supporting information
p. 237 - 241
(2019/01/10)
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- Catalytic Hydrogenation of Carboxamides with a Bifunctional Cp Ru Catalyst Bearing an Imidazol-2-ylidene with a Protic Aminoethyl Side Chain
-
Synthesis of a Cp Ru complex bearing an NH 2 -functionalized N -heterocyclic carbene (C-N H) was achieved by treatment of CpRuBr(isoprene) with an equimolar amount of a silver complex, which was generated from Ag 2 O and 1-(2-aminoethyl)-3-methylimidazolium bromide, in CH 3 CN at room temperature. The new CpRuBr(C-N H) complex showed a higher catalytic performance than the related CpRuCl(P-N H) and CpRuCl(N-N H) complexes. In the reaction of N -arylcarboxamides, the amine products were obtained in satisfactory yields under mild temperature conditions.
- Ikariya, Takao,Kawano, Teruhiro,Kayaki, Yoshihito,Watari, Ryo
-
supporting information
p. 2542 - 2547
(2019/06/08)
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- N-heterocyclic carbene palladium complex crystal, synthetic method thereof, and application thereof in preparation of amide compounds
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The invention discloses an N-heterocyclic carbene palladium complex crystal, a synthetic method thereof and application thereof in preparation of amide compounds. The structural formula of the complexcrystal is shown in the specification, or the complex crystal is prepared from an N-heterocyclic carbene ligand, Pd(CH3CN)2Cl2 and Ag2O in acetonitrile serving as a solvent. The N-heterocyclic carbene palladium complex crystal is relatively stable, wherein the raw materials used in the synthesis method are cheap and easy to obtain, so that the synthetic method is simple, convenient and easy to implement is simple in post-treamtent and is high in yield; and the N-heterocyclic carbene palladium complex crystal is used for catalyzing carbonylation carbon-nitrogen bond coupling reaction to prepare amide compounds and is high in catalytic activity, easy to operate and high in atom economy.
- -
-
Paragraph 0029-0032; 0079-0082
(2019/12/02)
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- Highly Chemoselective, Transition-Metal-Free Transamidation of Unactivated Amides and Direct Amidation of Alkyl Esters by N-C/O-C Cleavage
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The amide bond is one of the most fundamental functional groups in chemistry and biology and plays a central role in numerous processes harnessed to streamline the synthesis of key pharmaceutical and industrial molecules. Although the synthesis of amides is one of the most frequently performed reactions by academic and industrial scientists, the direct transamidation of tertiary amides is challenging due to unfavorable kinetic and thermodynamic contributions of the process. Herein, we report the first general, mild, and highly chemoselective method for transamidation of unactivated tertiary amides by a direct acyl N-C bond cleavage with non-nucleophilic amines. This operationally simple method is performed in the absence of transition metals and operates under unusually mild reaction conditions. In this context, we further describe the direct amidation of abundant alkyl esters to afford amide bonds with exquisite selectivity by acyl C-O bond cleavage. The utility of this process is showcased by a broad scope of the method, including various sensitive functional groups, late-stage modification, and the synthesis of drug molecules (>80 examples). Remarkable selectivity toward different functional groups and within different amide and ester electrophiles that is not feasible using existing methods was observed. Extensive experimental and computational studies were conducted to provide insight into the mechanism and the origins of high selectivity. We further present a series of guidelines to predict the reactivity of amides and esters in the synthesis of valuable amide bonds by this user-friendly process. In light of the importance of the amide bond in organic synthesis and major practical advantages of this method, the study opens up new opportunities in the synthesis of pivotal amide bonds in a broad range of chemical contexts.
- Li, Guangchen,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
-
supporting information
p. 11161 - 11172
(2019/08/07)
-
- Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
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An electrosynthesis method for amide bond formation has been developed in an attempt to increase the atom economy for this class of reactions. This "anion pool" method electrochemically generates strong nucleophiles from amine substrates. The amine nucleophiles then react with acid anhydrides to generate amides, and the by-product from this reaction undergoes further chemical transformations to generate pharmaceutically relevant benzoic esters. These one-pot reactions are operationally simple, are performed at room temperature, and avoid rare transition metals and added bases. The amide synthesis is amenable to primary and secondary amines and a variety of anhydrides with yields up to 90% obtained. Atom economy and process mass index (PMI) values calculated for this procedure indicate that this process can be considered greener compared to traditional amide synthesis routes used by industry. Furthermore, this electrochemical approach showed unique selectivity when substrates that contained two inequivalent amine moieties were examined.
- Mevan Dissanayake,Melville, Alex D.,Vannucci, Aaron K.
-
supporting information
p. 3165 - 3171
(2019/06/18)
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- Amide Synthesis from Thiocarboxylic Acids and Amines by Spontaneous Reaction and Electrosynthesis
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Amide bond formation is one of the most important basic reactions in chemistry. A catalyst-free approach for constructing amide bonds from thiocarboxylic acids and amines was developed. The mechanistic studies showed that the disulfide was the key intermediate for this amide synthesis. Thiobenzoic acids could be automatically oxidized to disulfides in air, thioaliphatic acids could be electro-oxidized to disulfides, and the resulting disulfides reacted with amines to give the corresponding amides. By this method, various amides could be easily synthesized in excellent yields without using any catalyst or activator. The successful synthesis of bioactive compounds also highlights the synthetic utility of this strategy in medicinal chemistry.
- Tang, Li,Matuska, Jack H.,Huang, Yu-Han,He, Yan-Hong,Guan, Zhi
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p. 2570 - 2575
(2019/06/13)
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- Synthesis of Amides by Mild Palladium-Catalyzed Aminocarbonylation of Arylsilanes with Amines Enabled by Copper(II) Fluoride
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A general Pd-catalyzed synthesis of amides by oxidative aminocarbonylation of arylsilanes under mild conditions was accomplished for the first time. The reaction is promoted by a commercially available copper(II) fluoride, which acts as a dual silane activator and mild oxidant, enabling highly efficient aminocarbonylation of versatile arylsilanes at atmospheric CO pressure. The reaction is tolerant of a wide range of arylsilanes and various sensitive halide functional groups as well as a broad scope of amines are compatible with this oxidative process using cheap CO. A significant aspect involves the increased efficiency by the catalyst system. The reaction represents a segue into the powerful Pd-catalyzed oxidative transformations of organosilanes.
- Zhang, Jin,Hou, Yanyan,Ma, Yangmin,Szostak, Michal
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p. 338 - 345
(2019/01/10)
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- Secondary/tertiary amide compound and synthesis method thereof
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The invention discloses a secondary/tertiary amide compound and a synthesis method thereof. The method comprises the following steps: adding arylsilane and an amine compound, a catalyst and an additive to a solvent, introducing CO under a certain pressure, carrying out a carbonylation reaction, and carrying out separation and purification to obtain the secondary/tertiary amide. The method for preparing the secondary/tertiary amide by the carbonylation reaction has the advantages of concision, high efficiency, directness in the reaction, high atom economy, and wide sources and good stability ofa substrate. The reaction system of the invention does not require inert gas protection, and has mild conditions, and the target product is easy to separate and the yield reaches up to 92% under optimized reaction conditions.
- -
-
Paragraph 0091; 0092; 0093; 0094; 0096
(2019/01/21)
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- Clickable coupling of carboxylic acids and amines at room temperature mediated by SO2F2: A significant breakthrough for the construction of amides and peptide linkages
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The construction of amide bonds and peptide linkages is one of the most fundamental transformations in all life processes and organic synthesis. The synthesis of structurally ubiquitous amide motifs is essential in the assembly of numerous important molecules such as peptides, proteins, alkaloids, pharmaceutical agents, polymers, ligands and agrochemicals. A method of SO2F2-mediated direct clickable coupling of carboxylic acids with amines was developed for the synthesis of a broad scope of amides in a simple, mild, highly efficient, robust and practical manner (>110 examples, >90% yields in most cases). The direct click reactions of acids and amines on a gram scale are also demonstrated using an extremely easy work-up and purification process of washing with 1 M aqueous HCl to provide the desired amides in greater than 99% purity and excellent yields.
- Wang, Shi-Meng,Zhao, Chuang,Zhang, Xu,Qin, Hua-Li
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p. 4087 - 4101
(2019/04/30)
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- Pd-Catalyzed Oxidation of Aldimines to Amides
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Methods for the synthesis of amides via the direct oxidation of imines are rarely reported. Here we report an efficient method for Pd-catalyzed oxidation of imines to amide derivatives by the use of cheap aqueous tert -butyl hydroperoxide as an oxidant through a Wacker-type reaction. This method is practically convenient and displays high functional group tolerance, allowing a variety of imines to transform into the corresponding amide derivatives in moderate to good yields.
- Gao, Shanshan,Ma, Yaorui,Chen, Weidong,Luo, Junfei
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supporting information
p. 2191 - 2194
(2018/10/02)
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- Rapidly Activating Pd-Precatalyst for Suzuki-Miyaura and Buchwald-Hartwig Couplings of Aryl Esters
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Esters are valuable electrophiles for cross-coupling due to their ubiquity and ease of synthesis. However, harsh conditions are traditionally required for the effective cross-coupling of ester substrates. Utilizing a recently discovered precatalyst, Pd-catalyzed Suzuki-Miyaura and Buchwald-Hartwig reactions involving cleavage of the C(acyl)-O bond of aryl esters that proceed under mild conditions are reported. The Pd(II) precatalyst is highly active because it is reduced to the Pd(0) active species more rapidly than previous precatalysts.
- Dardir, Amira H.,Melvin, Patrick R.,Davis, Ryan. M.,Hazari, Nilay,Mohadjer Beromi, Megan
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supporting information
p. 469 - 477
(2018/02/19)
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- Copper-catalyzed synthesis of arylcarboxamides from aldehydes and isocyanides: The isocyano group as an N1 synthon
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An interesting radical coupling reaction of aromatic aldehydes with isocyanides was disclosed for the synthesis of amides catalyzed by copper. According to the experimental results and mechanistic study, the isocyano group acted as an N1 synthon rather than exhibiting the carbene-like reactivity, exploiting a new reactivity profile of isocyanides.
- Liu, Jian-Quan,Shen, Xuanyu,Liu, Zhenhua,Wang, Xiang-Shan
-
supporting information
p. 6314 - 6317
(2017/08/10)
-
- Sulfur–Fluoride Exchange (SuFEx)-Mediated Synthesis of Sterically Hindered and Electron-Deficient Secondary and Tertiary Amides via Acyl Fluoride Intermediates
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Amide bond formation is one of the most executed reactions in chemistry and biology. This is largely due to the ubiquity of the amide functional group in biological molecules, natural products and pharmaceutically important drugs. We report here the development of “SuFExAmide”: a new sulfur–fluoride exchange (SuFEx) click chemistry based protocol for the efficient amidation of carboxylic acids via acyl fluoride intermediates. We have developed benzene-1,3-disulfonyl fluoride as a cost effective, powerful and versatile coupling agent, which delivers challenging secondary and tertiary amides in excellent yields from sterically hindered and electron-deficient amines. The straightforward method offers significant benefits over existing protocols in terms of substrate scope, efficiency and ease of operation and is demonstrated by the synthesis of 44 amides, including GNF6702, an antiprotozoal drug candidate. In the majority of cases, the amide products are obtained in high yield without the need for excess reagents or chromatographic purification.
- Smedley, Christopher J.,Barrow, Andrew S.,Spiteri, Christian,Giel, Marie-Claire,Sharma, Pallavi,Moses, John E.
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p. 9990 - 9995
(2017/08/01)
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- Rhodium-catalyzed electrophilic amination of arylboronic acids with secondary hydroxylamines
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A rhodium(III)-catalyzed electrophilic amination of arylboronic acids with secondary hydroxylamines has been developed. The rhodium catalysis is compatible with heteroarylboronic acids as well as acyl and alkoxycarbonyl protecting groups on the nitrogen of O-acylhydroxylamines, and the corresponding secondary anilines are obtained in good to excellent yields.
- Yasuhisa, Tomohiro,Hirano, Koji,Miura, Masahiro
-
supporting information
p. 463 - 465
(2017/04/03)
-
- A General Method for Two-Step Transamidation of Secondary Amides Using Commercially Available, Air- and Moisture-Stable Palladium/NHC (N-Heterocyclic Carbene) Complexes
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The first general method is reported for transamidation of secondary carboxamides catalyzed by Pd-NHC (NHC = N-heterocyclic carbene) complexes. Commercially available, air- and moisture-stable (NHC)Pd(R-allyl)Cl complexes can effect C-N cross-coupling of a wide range of N-Boc and N-Ts amides, obtained by selective amide N-functionalization, with non-nucleophilic anilines and sterically hindered amines in very good yields. The first use of versatile Pd-NHC complexes as catalysts is represented for transition-metal-catalyzed C(acyl)-N amination of amides by N-C activation.
- Meng, Guangrong,Lei, Peng,Szostak, Michal
-
supporting information
p. 2158 - 2161
(2017/04/27)
-
- Synthesis of N -Aryl Amides by Ligand-Free Copper-Catalyzed ipso -Amidation of Arylboronic Acids with Nitriles
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A facile copper-catalyzed ipso-amidation of arylboronic acids with nitriles has been developed. The method provides a highly efficient and economical synthesis of N-aryl amides with a broad substrate scope.
- Qiao, Yan,Li, Gaoqiang,Liu, Sha,Yangkai, Yujie,Tu, Jingxuan,Xu, Feng
-
supporting information
p. 1834 - 1838
(2017/04/06)
-
- Efficient and Mild Ullmann-Type N-Arylation of Amides, Carbamates, and Azoles in Water
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A simple, sustainable, efficient, mild, and low-cost protocol was developed for d-glucose-assisted Cu-catalyzed Ullmann reactions in water for amides, carbamates, and nitrogen-containing heterocycles. The reaction was compatible with diverse aryl/heteroaryl iodides, giving highly substituted pyridine, indole, or indazole rings. This method offers an attractive alternative to existing protocols, because the reaction proceeds in aqueous media, occurs at or near ambient temperature, and provides the N-arylated products in good to high yields.
- Bollenbach, Maud,Aquino, Pedro G. V.,de Araújo-Júnior, Jo?o Xavier,Bourguignon, Jean-Jacques,Bihel, Frédéric,Salomé, Christophe,Wagner, Patrick,Schmitt, Martine
-
supporting information
p. 13676 - 13683
(2017/10/10)
-
- Catalyst-Free Singlet Oxygen-Promoted Decarboxylative Amidation of α-Keto Acids with Free Amines
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A novel catalyst-free decarboxylative amidation of α-keto acids with amines under mild conditions has been developed. Advantages of the new protocol include avoidance of metal catalysts and high levels of functional group tolerance. In addition, the reaction can be scaled up and shows high chemoselectivity. Preliminary mechanistic studies suggest that singlet oxygen, generated from oxygen under irradiation, is the key promoter for this catalyst-free transformation.
- Xu, Wen-Tao,Huang, Bei,Dai, Jian-Jun,Xu, Jun,Xu, Hua-Jian
-
supporting information
p. 3114 - 3117
(2016/07/14)
-
- Experimental and computational insights into the nature of weak intermolecular interactions in trifluoromethyl-substituted isomeric crystalline N-methyl-N-phenylbenzamides
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The knowledge about the prevalence of weak interactions in terms of the nature and energetics associated with their formation is of significance in organic solids. In the present study, we have systematically explored the existence of different types of i
- Panini, Piyush,Chopra, Deepak
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p. 8720 - 8738
(2015/11/10)
-
- Chloroform as a Carbon Monoxide Precursor: In or Ex Situ Generation of CO for Pd-Catalyzed Aminocarbonylations
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Conditions for the rapid hydrolysis of chloroform to carbon monoxide (CO) using heterogeneous CsOH·H2O are described. CO and 13CO can be generated cleanly and rapidly under mild conditions and can be captured either in or ex situ in palladium-catalyzed aminocarbonylation reactions. Utilizing only 1-3 equiv of CO allows for the aminocarbonylation of aryl, vinyl, and benzyl halides with a wide variety of primary and secondary amines giving amide products in good to excellent yields. (Chemical Equation Presented).
- Gockel, Samuel N.,Hull, Kami L.
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supporting information
p. 3236 - 3239
(2015/07/15)
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- An efficient magnetic copper ferrite nanoparticle catalysed ligand and solvent free synthesis of N-aryl amide from aldoximes and iodobenzene
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A simple, efficient, and environmentally benign method has been reported for the synthesis of N-aryl amides using aldoximes and iodobenzene under ligand free and solvent free conditions and using magnetically separable copper ferrite nanoparticles as catalyst. The catalyst was characterised using XRD, FEG-SEM, EDAX, ICP-AES and TEM and tested for recyclability for up to five cycles.
- Sarode, Sachin A.,Bhojane, Jeevan M.,Nagarkar, Jayashree M.
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p. 105353 - 105358
(2015/12/30)
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- Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
-
OSU-6, an MCM-41 type hexagonal mesoporous silica with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures for a broad range of substrates. An added benefit is that the catalyst can be recycled and reused multiple times without significant loss of activity.
- Nammalwar, Baskar,Muddala, Nagendra Prasad,Watts, Field M.,Bunce, Richard A.
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p. 9101 - 9111
(2015/11/09)
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- Palladium-Catalyzed Aerobic Oxidative Dehydrogenation of Cyclohexenes to Substituted Arene Derivatives
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A palladium(II) catalyst system has been identified for aerobic dehydrogenation of substituted cyclohexenes to the corresponding arene derivatives. Use of sodium anthraquinone-2-sulfonate (AMS) as a cocatalyst enhances the product yields. A wide range of functional groups are tolerated in the reactions, and the scope and limitations of the method are described. The catalytic dehydrogenation of cyclohexenes is showcased in an efficient route to a phthalimide-based TRPA1 activity modulator.
- Iosub, Andrei V.,Stahl, Shannon S.
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p. 3454 - 3457
(2015/03/30)
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- Nickel-catalyzed dehydrogenative cross-coupling: Direct transformation of aldehydes into esters and amides
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By exploring a new mode of nickel-catalyzed cross-coupling, a method to directly transform both aromatic and aliphatic aldehydes into either esters or amides has been developed. The success of this oxidative coupling depends on the appropriate choice of catalyst and organic oxidant, including the use of either α,α,α-trifluoroacetophenone or excess aldehyde. Mechanistic data that supports a catalytic cycle involving oxidative addition into the aldehyde C-H bond is also presented.
- Whittaker, Aaron M.,Dong, Vy M.
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supporting information
p. 1312 - 1315
(2015/01/30)
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- Highly efficient dehydrogenative cross-coupling of aldehydes with amines and alcohols
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A common protocol for the synthesis of amides, esters and α-ketoesters via cross dehydrogenative coupling of aldehydes and amines/alcohols has been developed. The method is applicable to a wide variety of alcohols and amines as well as aliphatic and aromatic aldehydes. Also, the use of acetaldehyde for acetylation and ethyl glyoxalate to access 2-oxo-amino esters is presented for the first time.
- Deshidi, Ramesh,Rizvi, Masood Ahmad,Shah, Bhahwal Ali
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p. 90521 - 90524
(2015/11/11)
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- Aryl formate as bifunctional reagent: Applications in palladium-catalyzed carbonylative coupling reactions using in situ generated CO
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After decades of development, carbonylation reactions have become one of the most powerful tools in modern organic synthesis. However, the requirement of CO gas limits the applications of such reactions. Reported herein is a versatile and practical protocol for carbonylative reactions which rely on the cooperation of phenyl formate and nonaflate, and the generation of CO in situ. This protocol has a high functional-group tolerance and could be applied in carbonylations with C, N, and, O nucleophiles. The corresponding amides, alkynones, furanones, and aryl benzoates were synthesized in good yields. Transformers: A versatile and practical protocol for carbonylation reactions involve the cooperation of phenyl formate and nonaflate with generation of CO in situ. This protocol has a high functional-group tolerance and could be applied in carbonylative couplings with C, N, and O nucleophiles. The corresponding amides, alkynones, furanones, and aryl benzoates were synthesized in good yield.
- Li, Haoquan,Neumann, Helfried,Beller, Matthias,Wu, Xiao-Feng
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supporting information
p. 3183 - 3186
(2014/04/03)
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- Efficient cobalt-catalyzed C-N cross-coupling reaction between benzamide and aryl iodide in water
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A practical and efficient strategy for the N-arylation of benzamide catalysed by a Co(C2O4)·2H2O/dmeda system in water is reported. Under the optimized conditions, a wide variety of N-arylated products were obtained in good yields (up to 92%) using substituted aryl iodides.
- Tan, Bryan Yong-Hao,Teo, Yong-Chua
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supporting information
p. 7478 - 7481
(2014/12/11)
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- Copper catalyzed N-arylation between aryl halides and nitriles in water: An efficient tandem synthesis of benzanilides
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A series of benzanilide compounds were synthesized through copper-catalyzed tandem reactions. With the assistance of ionic liquid as phase transfer catalyst, aryl halides, and nitriles underwent a hydrolysis/coupling pathway to form benzanilides in water. Advantages of this reaction include the use of water as the environmental friendly solvent, short reaction time, and the tolerance of various functional groups. A proposed mechanism based on control experiments is also presented.
- Wang, Jichao,Yin, Xinchi,Wu, Jun,Wu, Datong,Pan, Yuanjiang
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p. 10463 - 10469
(2013/11/19)
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- Efficient manganese/copper bimetallic catalyst for N-arylation of amides and sulfonamides under mild conditions in water
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An efficient and mild method using a bimetallic MnF2/CuI catalyst at 60 °C in water was developed for the N-arylation of amides and sulfonamides with aryl halides. A variety of functionalized amides and sulfonamides were coupled with different substituted aryl halides to afford the corresponding N-arylated products in good to excellent yields (up to 97 %). An efficient method using a bimetallic MnF2/CuI catalyst in combination with trans-1,2-diaminocyclohexane as the ligand has been developed for the cross-coupling of benzamides and sulfonamides with differently substituted aryl iodides in water. The corresponding N-arylated products were obtained in good to excellent yields (up to 97 %) under the catalytic conditions. Copyright
- Teo, Yong-Chua,Yong, Fui-Fong,Ithnin, Idzham Khalid,Yio, Siew-Hui Trionna,Lin, Zhiyin
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supporting information
p. 515 - 524
(2013/02/26)
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- Role of intermolecular interactions involving organic fluorine in trifluoromethylated benzanilides
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Trifluoromethylated benzanilides, containing C(sp3)-F bonds, have been synthesized and their crystal and molecular structures have been investigated to highlight the significance of weak intermolecular interactions associated with the presence
- Panini, Piyush,Chopra, Deepak
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experimental part
p. 1972 - 1989
(2012/05/21)
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- Nickel-mediated N-arylation with arylboronic acids: An avenue to Chan-Lam coupling
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An efficient use of NiCl2·6H2O, for the cross-coupling of arylboronic acids with various N-nucleophiles, has been demonstrated. The method is practical and offers an alternative to the corresponding Cu-mediated Chan-Lam process for the construction of the C-N bond.
- Raghuvanshi, Dushyant Singh,Gupta, Amit Kumar,Singh, Krishna Nand
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supporting information
p. 4326 - 4329
(2012/10/29)
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- A simple copper-catalyzed synthesis of tertiary acyclic amides
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The N-arylation of aromatic and aliphatic secondary acyclic amides, known to be poor nucleophiles, has been accomplished using a simple and cheap copper catalytic system. The corresponding tertiary acyclic amides, which can be found in numerous biologically active compounds, have been obtained in good to excellent yields.
- Racine, Emilie,Monnier, Florian,Vors, Jean-Pierre,Taillefer, Marc
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supporting information; experimental part
p. 2818 - 2821
(2011/07/09)
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- Bis(cyclopentadienyldicarbonyliron) as a convenient carbon monoxide source in palladium-catalyzed carbonylative coupling of aryl iodides with amines, alcohols, and thiols
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Bis(cyclopentadienyldicarbonyliron) ([CpFe(CO)2]2) serves as a carbon monoxide source in carbonylative coupling reactions. Treatment of aryl iodides with primary amines in the presence of DBU and [CpFe(CO)2]2 under palladium catalysis provides the corresponding benzamides in good yields. Similar reactions with phenols and thiols provide the corresponding benzoate esters and thioesters, respectively. A catalytic amount of DMAP as an additive promoted the carbonylative coupling reactions with primary alcohol and secondary amine.
- Nakaya, Ryotaro,Yorimitsu, Hideki,Oshima, Koichiro
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experimental part
p. 904 - 906
(2011/12/05)
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- Manganese-catalyzed cleavage of a carbon-carbon single bond between carbonyl carbon and α-carbon atoms of ketones
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Singled out: Treatment of ketones with carbodiimides in the presence of a catalytic amount of either [{HMn(CO)4}3] or [Mn 2(CO)10] gave amides in good to excellent yields. In this reaction, the carbon-carbon single bond of a ketone is cleaved efficiently. The reaction also proceeded by using isocyanates instead of carbodiimides. Copyright
- Kuninobu, Yoichiro,Uesugi, Tadamasa,Kawata, Atsushi,Takai, Kazuhiko
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p. 10406 - 10408
(2011/12/04)
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- Palladium complexes of bis(acyclic diaminocarbene) ligands with chiral N-substituents and 8-membered chelate rings
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Reaction of cis-dichloridobis(p-trifluoromethylphenylisocyanide)palladium(II) with N,N′-bis[(R)-1-phenylethyl]-1,3-diaminopropane afforded an enantiomerically pure, C1-symmetric bis(acyclic diaminocarbene)PdCl2 complex in 41% yield.
- Wanniarachchi, Yoshitha A.,Subramanium, Sri S.,Slaughter, LeGrande M.
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experimental part
p. 3297 - 3305
(2010/01/11)
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- N,N-carbonyldiimidazole-mediated amide coupling: Significant rate enhancement achieved by acid catalysis with imidazole - HCI
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Over a series of 10 aromatic amines we show the rate of CDI mediated amidation to be significantly enhanced upon introduction of imidazole·HCI as a proton source for acid catalysis. Our work supports and provides an application for previous investigations into the imidazolium effect, thus increasing the scope of CDI as an amide-coupling reagent with aromatic amines. The influence of the relative pKa of the amines studied on the rate of reaction was also investigated.
- Woodman, Emily K.,Chaffey, Julian G. K.,Hopes, Philip A.,Hose, David R. J.,Gilday, John P.
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supporting information; experimental part
p. 106 - 113
(2010/04/22)
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- Thermal Diels-Alder reactions of 3-(benzoylamino)-6-(polyfluoroalkyl)pyran- 2-ones - New synthesis of p-(polyfluoroalkyl)anilines
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A new practical method for the regioselective synthesis of the N-benzoyl-4-(polyfluoroalkyl) anilines 5a-g by thermal Diels-Alder cycloaddition of 5-substituted 3-(benzoylamino)-6-(polyfluoroalkyl)pyran-2-ones 1a-e with fluorostyrenes 2 and 7, acetylenes
- Tolmachova, Nataliya A.,Gerus, Igor I.,Vdovenko, Sergey I.,Essers, Michael,Froehlich, Roland,Haufe, Guenter
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p. 4704 - 4709
(2007/10/03)
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