- Generation of Oxyphosphonium Ions by Photoredox/Cobaloxime Catalysis for Scalable Amide and Peptide Synthesis in Batch and Continuous-Flow
-
Phosphine-mediated deoxygenative nucleophilic substitutions, such as the Mitsunobu reaction, are of great importance in organic synthesis. However, the conventional protocols require stoichiometric oxidants to trigger the formation of the oxyphosphonium i
- Chen, Xiangyang,Houk, Kendall N.,Mo, Jia-Nan,Su, Junqi,Umanzor, Alexander,Zhang, Zheng,Zhao, Jiannan
-
supporting information
(2022/01/06)
-
- AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
-
The present invention generally relates to a process for selective and direct activation and subsequent amidation of aliphatic and aromatic carboxylic acids to afford an amide R3CONR1R2. That the process is capable of delivering gaseous or low-boiling point amines provides a major advantage over existing methodologies, which involves an intermediate of triacyloxyborane-amine complex [(R3CO2)3—B—NHR1R2]. This procedure readily produces primary, secondary, and tertiary amides, and is compatible with the chirality of the acid and amine involved. The preparation of known pharmaceutical molecules and intermediates has also been demonstrated.
- -
-
Paragraph 0008-0009; 0063-0064
(2022/03/04)
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- Deoxygenative hydroboration of primary, secondary, and tertiary amides: Catalyst-free synthesis of various substituted amines
-
Transformation of relatively less reactive functional groups under catalyst-free conditions is an interesting aspect and requires a typical protocol. Herein, we report the synthesis of various primary, secondary, and tertiary amines through hydroboration of amides using pinacolborane under catalyst-free and solvent-free conditions. The deoxygenative hydroboration of primary and secondary amides proceeded with excellent conversions. The comparatively less reactive tertiary amides were also converted to the corresponding N,N-diamines in moderate yields under catalyst-free conditions, although alcohols were obtained as a minor product.
- Yi, Jaeeun,Kim, Hyun Tae,Jaladi, Ashok Kumar,An, Duk Keun
-
supporting information
p. 129 - 132
(2021/11/17)
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- Nickel-Catalyzed Reductive Cross-Coupling of N-Acyl and N-Sulfonyl Benzotriazoles with Diverse Nitro Compounds: Rapid Access to Amides and Sulfonamides
-
Herein we report a Ni-catalyzed reductive transamidation of conveniently available N-acyl benzotriazoles with alkyl, alkenyl, and aryl nitro compounds, which afforded various amides with good yields and a broad substrate scope. The same catalytic reaction conditions were also applicable for N-sulfonyl benzotriazoles, which could undergo smooth reductive coupling with nitroarenes and nitroalkanes to afford the corresponding sulfonamides.
- Qu, Erdong,Li, Shangzhang,Bai, Jin,Zheng, Yan,Li, Wanfang
-
-
- Photocatalysis in Aqueous Micellar Media Enables Divergent C-H Arylation and N-Dealkylation of Benzamides
-
Photocatalysis in aqueous micellar media has recently opened wide avenues to activate strong carbon-halide bonds. So far, however, it has mainly explored strongly reducing conditions, restricting the available chemical space to radical or anionic reactivity. Here, we demonstrate a controllable, photocatalytic strategy that channels the reaction of chlorinated benzamides via either a radical or a cationic pathway, enabling a chemodivergent C-H arylation or N-dealkylation. The catalytic system operates under mild conditions with methylene blue as a photocatalyst and blue LEDs as the light source. Factors determining the reactivity of substrates, their selectivity, and preliminary mechanistic studies are presented.
- Cybularczyk-Cecotka, Martyna,Predygier, J?drzej,Crespi, Stefano,Szczepanik, Joanna,Giedyk, MacIej
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p. 3543 - 3549
(2022/03/27)
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- Chemoselective Electrosynthesis Using Rapid Alternating Polarity
-
Challenges in the selective manipulation of functional groups (chemoselectivity) in organic synthesis have historically been overcome either by using reagents/catalysts that tunably interact with a substrate or through modification to shield undesired sites of reactivity (protecting groups). Although electrochemistry offers precise redox control to achieve unique chemoselectivity, this approach often becomes challenging in the presence of multiple redox-active functionalities. Historically, electrosynthesis has been performed almost solely by using direct current (DC). In contrast, applying alternating current (AC) has been known to change reaction outcomes considerably on an analytical scale but has rarely been strategically exploited for use in complex preparative organic synthesis. Here we show how a square waveform employed to deliver electric current - rapid alternating polarity (rAP) - enables control over reaction outcomes in the chemoselective reduction of carbonyl compounds, one of the most widely used reaction manifolds. The reactivity observed cannot be recapitulated using DC electrolysis or chemical reagents. The synthetic value brought by this new method for controlling chemoselectivity is vividly demonstrated in the context of classical reactivity problems such as chiral auxiliary removal and cutting-edge medicinal chemistry topics such as the synthesis of PROTACs.
- Baran, Phil S.,Carlson, Ethan,Edwards, Jacob T.,Hayashi, Kyohei,Kawamata, Yu,Saito, Masato,Shaji, Shobin,Simmons, Bryan J.,Waldmann, Dirk,Zapf, Christoph W.
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supporting information
p. 16580 - 16588
(2021/10/20)
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- Method for preparing amide from carboxylic acid under irradiation of blue light by taking iridium and cobalt complexes as catalysts
-
The invention relates to a method for preparing amide from carboxylic acid under the irradiation of blue light by taking iridium and cobalt complexes as catalysts, and belongs to the field of chemistry. The method comprises the following step of: by taking R substituted carboxylic acid and R1' and R2' substituted amines as raw materials, triphenylphosphine as a deoxidizing agent, [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 as a photocatalyst and Co(dmgH)(dmgH2)Cl2 as a metal complex catalyst, reacting in dichloromethane in an inert atmosphere and under the irradiation of blue light to obtain an amide compound, wherein R is an aryl group, a heteroaryl group, a protected amino group, a substituted alkyl group, a substituted aryl group or a substituted protected amino group, R1' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group, and R2' is a hydrogen group, a substituted alkyl group, a phenyl group or a substituted phenyl group.
- -
-
Paragraph 0101-0102
(2021/05/12)
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- Synthesis of Benzoisoselenazolones via Rh(III)-Catalyzed Direct Annulative Selenation by Using Elemental Selenium
-
Isoselenazolone derivatives have attracted significant research interest because of their potent therapeutic activities and indispensable applications in organic synthesis. Efficient construction of functionalized isoselenazolone scaffolds is still challenging, and thus new synthetic approaches with improved operational simplicity have been of particular interest. In this manuscript, we introduce a rhodium-catalyzed direct selenium annulation by using stable and tractable elemental selenium. A series of benzamides as well as acrylamides were successfully coupled with selenium under mild reaction conditions, and the obtained isoselenazolones could be pivotal synthetic precursors for several organoselenium compounds. Based on the designed control experiments and X-ray absorption spectroscopy measurements, we propose an unprecedented selenation mechanism involving a highly electrophilic Se(IV) species as the reactive selenium donor. The reaction mechanism was further verified by a computational study.
- Xu-Xu, Qing-Feng,Nishii, Yuji,Uetake, Yuta,Sakurai, Hidehiro,Miura, Masahiro
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supporting information
p. 17952 - 17959
(2021/11/16)
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- Trifluoroacetic Acid Hydroxylamine System as Organocatalyst Reagent in a One-Pot Salt Free Process for the Synthesis of Caprolactam and Amides of Industrial Interest
-
In this work we studied the reactivity of the Trifluoroacetic acid hydroxylamine system in the one step salt free synthesis of amides from ketones. A particular regards was paid to the caprolactam synthesis because of its industrial relevance. Synthesis, reactivity and characterization of the hydroxylamine trifluoroacetate is given. Fast oximation reaction of several ketones was gained at room temperature (1?h of reaction quantitative conversion for several ketones). In the same reactor, by raising the temperature at 383?K, the Beckmann rearrangement of the so obtained oximes is easily accomplished in the presence of three equivalent of TFA. The possibility of obtaining the trifluoroacetate of the hydroxylamine with a modified nitric acid hydrogenation reactions was verified, too. Reuse of solvent and trifluoroacetic acid is easily achieved by distillation. Graphical abstract: Salt free one-pot caprolactam and amides process catalyzed by CF3COOH, in the presence of NH2OH TFA as the oximation agent.[Figure not available: see fulltext.].
- Manente,Pietrobon,Ronchin,Vavasori
-
p. 3543 - 3549
(2021/03/30)
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- Catalytic asymmetric [3+2] cycloaddition of isomünchnones with methyleneindolinones
-
An efficient enantioselective [3+2] cycloaddition of isomünchnones with methyleneindolinones that are generated by anin situintramolecular addition of the carbonyl group to rhodium carbenes is realized with a chiralN,N′-dioxide/Zn(ii) complex as a Lewis acid. A series of chiral oxa-bridged 3-spiropiperidines are obtained in high yields with excellent dr and excellent ee values.
- Feng, Xiaoming,Hu, Xinyue,Lin, Lili,Wang, Kaixuan,Xu, Chaoran,Zhou, Yuqiao
-
supporting information
p. 8917 - 8920
(2021/09/10)
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- Copper-catalyzed oxidative methylation of sulfonamides by dicumyl peroxide
-
A novel and facile copper-catalyzed methylation of sulfonamides was herein demonstrated. The practical transformation took place readily under the oxidative conditions, and N-methyl amides (23 examples) were successfully furnished in high efficiency (up to 90% yields). Dicumyl peroxide was considered to act not only as the oxidant in the system, but also methyl donor for the methylation protocol.
- Che, Shiying,Zhu, Qiao,Luo, Zhenghong,Lian, Yan,Zhao, Zijian
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p. 935 - 942
(2021/01/05)
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- Nickel Hydride Catalyzed Cleavage of Allyl Ethers Induced by Isomerization
-
This report discloses the deallylation of O - and N -allyl functional groups by using a combination of a Ni-H precatalyst and excess Bronsted acid. Key steps are the isomerization of the O - or N -allyl group through Ni-catalyzed double-bond migration followed by Bronsted acid induced O/N-C bond hydrolysis. A variety of functional groups are tolerated in this protocol, highlighting its synthetic value.
- Kathe, Prasad M.,Berkefeld, Andreas,Fleischer, Ivana
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supporting information
p. 1629 - 1632
(2021/02/09)
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- Assemblies of 1,4-Bis(diarylamino)naphthalenes and Aromatic Amphiphiles: Highly Reducing Photoredox Catalysis in Water
-
Host-guest assemblies of a designed 1,4-bis(diarylamino)naphthalene and V-shaped aromatic amphiphiles consisting of two pentamethylbenzene moieties bridged by an m -phenylene unit bearing two hydrophilic side chains emerged as highly reducing photoredox catalysis systems in water. An efficient demethoxylative hydrogen transfer of Weinreb amides has been developed. The present supramolecular strategy permits facile tuning of visible-light photoredox catalysis in water.
- Abe, Manabu,Akita, Munetaka,Chitose, Youhei,Hyodo, Yuki,Koike, Takashi,Takahashi, Keigo,Yoshizawa, Michito
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supporting information
(2021/10/21)
-
- Method for preparing primary and secondary amide compounds
-
The invention belongs to the field of organic chemical synthesis, and particularly relates to a method for preparing primary and secondary amide compounds. The method for preparing primary and secondary amide compounds comprises the following steps of carrying out catalytic reduction on an N-substituted amide compound at 30-130 DEG C by using a protic solvent as a reduction reagent and a dichloro(p-methyl isopropylbenzene) ruthenium (II) dimer complex as a catalyst to obtain a reaction solution after the reduction reaction is finished, and carrying out post-treatment on the reaction solution to obtain the corresponding primary amide compound or secondary amide compound. According to the method for preparing the primary and secondary amide compounds, the transfer hydrogenation reaction of nitrogen-oxygen and nitrogen-carbon bonds is realized, the reaction conditions are mild and simple, the substrate application range is wide, the operation is convenient, and the corresponding primary amide compound or secondary amide compound is obtained with high efficiency and high selectivity.
- -
-
Paragraph 0156-0166
(2021/02/06)
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- Method for efficiently synthesizing primary amide and N-methyl secondary amide compounds
-
The invention discloses a method for efficiently synthesizing primary amide and N-methyl secondary amide compounds, which specifically comprises the following steps: adding metal amine borane MRNHBH3 into a reaction container filled with anhydrous THF (tetrahydrofuran) under anhydrous and anaerobic conditions, wherein M=Na or K, and R=H or Me; adding an ester compound R 'CO2R ''(R' is alkyl or aryl) and R'' is alkyl or aryl) into a reaction kettle, carrying out stirring reaction at room temperature, and carrying out post-treatment to obtain the pure target product primary amide compound or N-methyl secondary amide compound. The preparation method is simple to operate, low in toxicity, harmless, safe, reliable and suitable for large-scale production.
- -
-
Paragraph 0007; 0012
(2021/08/07)
-
- Iron-Catalyzed C-C Single-Bond Cleavage of Alcohols
-
An iron-catalyzed deconstruction/hydrogenation reaction of alcohols through C-C bond cleavage is developed through photocatalysis, to produce ketones or aldehydes as the products. Tertiary, secondary, and primary alcohols bearing a wide range of substituents are suitable substrates. Complex natural alcohols can also perform the transformation selectively. A investigation of the mechanism reveals a procedure that involves chlorine radical improved O-H homolysis, with the assistance of 2,4,6-collidine.
- Liu, Wei,Wu, Qiang,Wang, Miao,Huang, Yahao,Hu, Peng
-
supporting information
p. 8413 - 8418
(2021/11/01)
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- Photoinduced Cross-Coupling of Aryl Iodides with Alkenes
-
A protocol for photoinduced cross-coupling of aryl iodides having polar π-functional groups or elongated π-conjugation with alkenes has been developed. The radical cascade mechanism involving generation of aryl radicals via C-I bond homolysis of photoexcited aryl iodides and their subsequent addition to alkenes is proposed. The method enables iodide-selective cross-coupling over other halogen leaving groups with functional group compatibility on both arene and alkene motifs.
- Liu, Yuliang,Li, Haoyu,Chiba, Shunsuke
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p. 427 - 432
(2021/01/26)
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- Electron Transfer Photoredox Catalysis: Development of a Photoactivated Reductive Desulfonylation of an Aza-Heteroaromatic Ring
-
Herein, we report a protocol for desulfonylation of aza-heteroaromatic rings via photoinduced electron transfer and hydrogen atom transfer. This general protocol has a wide substrate range and moderate to good yields. The utility of the method was demonstrated by the chemoselective desulfonylation of a molecule containing both an aliphatic and an aromatic sulfonamide. (Figure presented.).
- Qiang-Liu,Liu, Yu-Xiu,Song, Hong-Jian,Wang, Qing-Min
-
supporting information
p. 3110 - 3115
(2020/07/04)
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- Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant
-
An unprecedented N-demethylation of N-methyl amides has been developed by use of N-fluorobenzenesulfonimide as an oxidant with the aid of a copper catalyst. The conversion of amides to carbinolamines involves successive single-electron transfer, hydrogen-atom transfer, and hydrolysis, and is accompanied by formation of N-(phenylsulfonyl)benzenesulfonamide. Carbinolamines spontaneously decompose to N-demethylated amides and formaldehyde, because of their inherent instability.
- Yi, Xuewen,Yi, Xuewen,Lei, Siyu,Liu, Wangsheng,Che, Fengrui,Yu, Chunzheng,Liu, Xuesong,Wang, Zonghua,Zhou, Xin,Zhang, Yuexia
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supporting information
p. 4583 - 4587
(2020/05/05)
-
- Iridium-catalyzed, ligand-controlled directed alkynylation and alkenylation of arenes with terminal alkynes
-
We report iridium-catalyzed C-C formation between benzamides and terminal alkynes. With the choice of a suitable ligand, a C-H alkynylation or alkenylation product could be obtained selectively. The directed C-H alkynylation proceeded without the need for an external oxidant, while the directed C-H alkenylation likely involves an unusual vinylidene mechanism. This divergent reactivity provides access to both alkynylation and alkenylation products from the same set of starting materials.
- Sun, Xin,Zhao, Wei,Li, Bi-Jie
-
supporting information
p. 1298 - 1301
(2020/02/04)
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- Ru(II)-Catalyzed Oxidative Olefination of Benzamides: Switchable Aza-Michael and Aza-Wacker Reaction for Synthesis of Isoindolinones
-
Selective tandem oxidative C-H olefination-aza-Michael/aza-Wacker reaction of N-arylbenzamides is achieved by fine-tuning between base and additive to access valuable 3-oxoisoindolinyls and 3-oxoisoindolinylidenes, respectively. Careful optimization and c
- Kumar, Manoj,Verma, Akhilesh K.,Verma, Shalini
-
supporting information
(2020/06/25)
-
- Synthesis of CF3-containing isoindolinone derivatives through rhodium-catalyzed oxidative coupling of benzamides with 2-trifluoromethylacrylate
-
The oxidative coupling of benzamides with methyl 2- trifluoromethylacrylate proceeds smoothly under rhodium(III) catalysis to produce trifluoromethyl-substituted isoindolinone derivatives. The catalyst system [CpERhCl2]2/AgSbF6 is effective for the oxidat
- Yoshimoto, Risa,Morisaka, Hideaki,Usuki, Yoshinosuke,Shibata, Yu,Tanaka, Ken,Satoh, Tetsuya
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supporting information
p. 1481 - 1483
(2020/12/31)
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- Visible-light-promoted acyl radical cascade reaction for accessing acylated isoquinoline-1,3(2: H,4 H)-dione derivatives
-
A visible-light-promoted decarboxylative acyl radical acylation/cyclization cascade reaction of N-methacryloylbenzamides for accessing acylated isoquinoline-1,3(2H,4H)-dione derivatives was described. In this report, α-keto acids were used for generating acyl radicals and inducing radical acylations. This protocol features mild reaction conditions, operational practicality and a broad substrate scope.
- Hu, Yulai,Huang, Danfeng,Huo, Congde,Liu, Xuan,Su, Yingpeng,Wang, Ke-Hu,Xue, Wenxuan,Zhang, Rong,Zhao, Yanan
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supporting information
p. 1940 - 1948
(2020/03/23)
-
- Rhodium-Catalyzed Electrooxidative C?H Olefination of Benzamides
-
Metal-catalyzed chelation-assisted C?H olefinations have emerged as powerful tools for the construction of functionalized alkenes. Herein, we describe the rhoda-electrocatalyzed C?H activation/alkenylation of arenes. The olefinations of challenging electron-poor benzamides were thus accomplished in a fully dehydrogenative fashion under electrochemical conditions, avoiding stoichiometric chemical oxidants, and with H2 as the only byproduct. This versatile alkenylation reaction also features broad substrate scope and used electricity as a green oxidant.
- Ackermann, Lutz,Struwe, Julia,Zhang, Yan
-
supporting information
p. 15076 - 15080
(2020/06/20)
-
- Nucleophilic Addition to Nitrones Using a Flow Microreactor
-
Nucleophilic addition reactions of soft carbon nucleophiles to nitrones in a flow microreactor are reported for the first time. Under microflow conditions at 30 to 0 °C, a range of nitrones can be efficiently transformed into the corresponding oxyiminium ions by reaction with either acyl halides or trialkylsilyl triflates. These can subsequently undergo the addition of nucleophiles including allyltributylstannane, ketene methyl tert-butyldimethylsilyl acetal, and N-silyl ketene imines to afford the corresponding adducts in high yields; such reactions at a similar temperature under batch conditions resulted in lower yields because of undesired side reactions.
- Arakawa, Yukihiro,Imada, Yasushi,Minagawa, Keiji,Okamoto, Takuma,Ueta, Shun
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p. 866 - 870
(2020/05/28)
-
- Divergent Strain-Release Amino-Functionalization of [1.1.1]Propellane with Electrophilic Nitrogen-Radicals
-
Herein we report the development of a photocatalytic strategy for the divergent preparation of functionalized bicyclo[1.1.1]pentylamines. This approach exploits, for the first time, the ability of nitrogen-radicals to undergo strain-release reaction with [1.1.1]propellane. This reactivity is facilitated by the electrophilic nature of these open-shell intermediates and the presence of strong polar effects in the transition-state for C?N bond formation/ring-opening. With the aid of a simple reductive quenching photoredox cycle, we have successfully harnessed this novel radical strain-release amination as part of a multicomponent cascade compatible with several external trapping agents. Overall, this radical strategy enables the rapid construction of novel amino-functionalized building blocks with potential application in medicinal chemistry programs as p-substituted aniline bioisosteres.
- Kim, Ji Hye,Ruffoni, Alessandro,Al-Faiyz, Yasair S. S.,Sheikh, Nadeem S.,Leonori, Daniele
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p. 8225 - 8231
(2020/03/04)
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- Direct synthesis of amides from nonactivated carboxylic acids using urea as nitrogen source and Mg(NO3)2or imidazole as catalysts
-
A new method for the direct synthesis of primary and secondary amides from carboxylic acids is described using Mg(NO3)2·6H2O or imidazole as a low-cost and readily available catalyst, and urea as a stable, and easy to manipulate nitrogen source. This methodology is particularly useful for the direct synthesis of primary and methyl amides avoiding the use of ammonia and methylamine gas which can be tedious to manipulate. Furthermore, the transformation does not require the employment of coupling or activating agents which are commonly required.
- Blacker, A. John,Chhatwal, A. Rosie,Lomax, Helen V.,Marcé, Patricia,Williams, Jonathan M. J.
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p. 5808 - 5818
(2020/06/21)
-
- Dealkoxylation ofN-alkoxyamides without an external reductant driven by Pd/Al cooperative catalysis
-
Lewis acid-assisted palladium-catalysed dealkoxylation ofN-alkoxyamides has been developed. This reaction proceeded smoothly with a range ofN-alkoxyamides in the absence of an external reductant, thereby establishing a convenient and reductant-free protocol. In addition, a gram-scale reaction could be achieved. Preliminary mechanistic investigations indicated that β-hydrogen elimination from a palladium alkoxide intermediate generated an intramolecular hydride source.
- Suzuki, Hirotsugu,Shiomi, Takahiro,Yoneoka, Kenji,Matsuda, Takanori
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supporting information
p. 7545 - 7548
(2020/10/15)
-
- Base-controlled product switch in the ruthenium-catalyzed protodecarbonylation of phthalimides: A mechanistic study
-
The whole reaction mechanism of the ruthenium-catalyzed protodecarbonylation of N-substituted phthalimides into secondary amides was unravelled by a combined experimental and theoretical study. The chemoselectivity of the reaction, which is catalyzed by para-cymene coordinated Ru(ii) species all over the catalytic cycle, is exclusively controlled by the unique roles of the bases. Meanwhile, in the presence of K2CO3 or KOH at high temperatures, the same product (benzamide) is mainly formed, whereas at low temperatures, KOH led to an unexpected side-product (phthalamic acid) and no reactivity was observed with K2CO3. The non-covalent interactions between the potassium cations and the different carbonyl groups in the molecules are key to providing a thermodynamically favourable pathway with energetically accessible transition states. The unexpected formation of carbon dioxide (CO2) in the course of the reaction originates from the phthalimide substrate and the base K2CO3 in two different elementary steps, respectively.
- D'Alterio, Massimo Christian,Yuan, Yu-Chao,Bruneau, Christian,Talarico, Giovanni,Gramage-Doria, Rafael,Poater, Albert
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p. 180 - 186
(2020/01/13)
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- Amine-Mediated Bond Cleavage in Oxidized Lignin Models
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Introducing amines/ammonia into lignin cracking will allow novel bond cleavage pathways. Herein, a method of amines/ammonia-mediated bond cleavage in oxidized lignin β-O-4 models was studied using a copper catalyst at room temperature, demonstrating the effect of the amine source on the selectivity of products. For primary and secondary aliphatic amines, lignin ketone models underwent oxidative Cα?Cβ bond cleavage and Cα?N bond formation to generate aromatic amides. For ammonia, the competition between oxygen and ammonia determined the selectivity between Cα?N and Cβ?N bond formation, generating amides and α-keto amides, respectively. For tertiary amines, the lignin models underwent oxidative Cα?Cβ bond cleavage to benzoic acids. Control experiments indicated that amines act as nucleophiles attacking at the Cα or Cβ position of the oxidized β-O-4 linkage to be cleaved. This study represents a novel example that the breakage of oxidized lignin model can be regulated by amines with a copper catalyst.
- Li, Hongji,Liu, Meijiang,Liu, Huifang,Luo, Nengchao,Zhang, Chaofeng,Wang, Feng
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p. 4660 - 4665
(2020/07/04)
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- Amine-boranes as Dual-Purpose Reagents for Direct Amidation of Carboxylic Acids
-
Amine-boranes serve as dual-purpose reagents for direct amidation, activating aliphatic and aromatic carboxylic acids and, subsequently, delivering amines to provide the corresponding amides in up to 99% yields. Delivery of gaseous or low-boiling amines as their borane complexes provides a major advantage over existing methodologies. Utilizing amine-boranes containing borane incompatible functionalities allows for the preparation of functionalized amides. An intermolecular mechanism proceeding through a triacyloxyborane-amine complex is proposed.
- Choudhary, Shivani,Hamann, Henry J.,Ramachandran, P. Veeraraghavan
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supporting information
(2020/11/13)
-
- Atom-Economical and Tandem Conversion of Nitriles to N-Methylated Amides Using Methanol and Water
-
A cobalt complex catalyzed tandem conversion of nitrile to N-methylated amide is described using a methanol and water mixture. Using this protocol, several nitriles were directly and efficiently converted to the desired N-methylated amides. Kinetic experiments using H2O18 and CD3OD suggested that water and methanol were the source of the oxygen atom and methyl group, respectively, in the final N-methylated amides. Importantly, the participation of active Co(I)-H species in this transformation was realized from the control experiment. The kinetic isotope effect (KIE) study suggested that the activation of the C-H bond of methanol was a kinetically important step. The Hammett plot confirmed that the reaction was faster with the electron deficient nitriles. In addition, the plausible pathway for the formation of N-methylated amides from the nitriles was supported by the computational study.
- Paul, Bhaskar,Maji, Milan,Kundu, Sabuj
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p. 10469 - 10476
(2019/11/05)
-
- Cobalt-catalyzed carbonylative synthesis of phthalimides from n-(pyridin-2-ylmethyl)benzamides with tfben as the co source
-
A cobalt-catalyzed direct carbonylative synthesis of phthalimide motifs from N-(pyridin-2-ylmethyl)benzamides has been developed. Various phthalimide derivatives were obtained in moderate to excellent yields (up to 98percent) by using 2-picolylamine as an efficient directing group and benzene-1,3,5-triyl triformate (TFBen) as a convenient CO surrogate.
- Fu, Lu-Yang,Wu, Xiao-Feng,Ying, Jun
-
-
- Rhenium-Catalyzed Phthalide Synthesis from Benzamides and Aldehydes via C-H Bond Activation
-
The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C-H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation byproducts.
- Jia, Bing,Yang, Yunhui,Jin, Xiqing,Mao, Guoliang,Wang, Congyang
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supporting information
p. 6259 - 6263
(2019/09/06)
-
- Chemoselective Synthesis of Aryl Ketones from Amides and Grignard Reagents via C(O)-N Bond Cleavage under Catalyst-Free Conditions
-
Conversion of a wide range of N-Boc amides to aryl ketones was achieved with Grignard reagents via chemoselective C(O)-N bond cleavage. The reactions proceeded under catalyst-free conditions with different aryl, alkyl, and alkynyl Grignard reagents. α-Ketoamide was successfully converted to aryl diketones, while α,β-unsaturated amide underwent 1,4-addition followed by C(O)-N bond cleavage to provide diaryl propiophenones. N-Boc amides displayed higher reactivity than Weinreb amides with Grignard reagents. A broad substrate scope, excellent yields, and quick conversion are important features of this methodology.
- Sureshbabu, Popuri,Azeez, Sadaf,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
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p. 11823 - 11838
(2019/10/02)
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- Method for preparing derivatives of benzamide under microwave condition in aqueous phase
-
The invention discloses a method for preparing derivatives of benzamide under a microwave condition in an aqueous phase. A coupling reaction is carried out between substituted benzoic acid and amine under the microwave condition in the aqueous phase. The method for preparing the derivatives of benzamide is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applicable to a large number of functional groups, is high in yield, produces fewer by-products, and further is easy to operate, safe, low in cost and environmentally friendly. A formula is shown in the description.
- -
-
Paragraph 0019
(2019/03/28)
-
- Ruthenium-Catalyzed Synthesis of N-Methylated Amides using Methanol
-
An efficient synthesis of N-methylated amides using methanol in the presence of a ruthenium(II) catalyst is realized. Notably, applying this process, tandem C-methylation and N-methylation were achieved to synthesize α-methyl N-methylated amides. In addition, several kinetic studies and control experiments with the plausible intermediates were performed to understand this novel protocol. Furthermore, detailed computational studies were carried out to understand the mechanism of this transformation.
- Paul, Bhaskar,Panja, Dibyajyoti,Kundu, Sabuj
-
supporting information
p. 5843 - 5847
(2019/08/26)
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- Generation of alkyl radicals from alkylsilyl peroxides and their applications to C-N or C-O bond formations
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This article describes a novel method for the generation of alkyl radicals from alkylsilyl peroxides and their applications to the Cu-catalyzed mono-N-alkylation of amides or arylamines, and to the O-alkylation of carboxylic acids. The use of alkylsilyl peroxides as alkyl radical sources includes the following synthetic advantages: i) various alkylsilyl peroxides can be readily synthesized from the corresponding alcohols and be stored at bench, and ii) a variety of alkyl radicals can be generated efficiently under mild conditions.
- Sakurai, Shunya,Kato, Terumasa,Sakamoto, Ryu,Maruoka, Keiji
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p. 172 - 179
(2018/12/11)
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- Formation of Aryl [1-Cyano-4-(dialkylamino)butadienyl] Ketones from Pyridines
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Treatment of 2-chloropyridine with LDA and the Weinreb amide of benzoic acid afforded three unusual products, namely N -methylbenzamide, 2-chloropyridine-3-methanol, and the ring-opened addition product. This same final product could also be obtained from 2-chloro-3-benzoylpyridine on treatment with LDA. Mechanistic insight for the formation of these products is provided.
- Gim, Hyo Jin,Jung, Michael E.
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p. 2548 - 2552
(2019/06/08)
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- Aerobic Activation of C-H Bond in Amines Over a Nanorod Manganese Oxide Catalyst
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The development of heterogeneous catalysts for the synthesis of pharmaceutically relevant compounds is always important for chemistry research. Here, we report a selective aerobic oxidation of aromatic and aliphatic amines to corresponding amides over a nanorod manganese oxide (NR-MnOx) catalyst. The kinetic studies reveal that the NR-MnOx catalyzed amine-to-amide reaction proceeds the oxidative dehydrogenation of the amines into nitriles, followed by hydrolysis of nitrile into amides. The NR?MnOx exhibits fast kinetics and high selectivities in these steps, as well as hinders the by-product formation. More importantly, the NR-MnOx catalyst is stable and reusable in the continuous recycle tests with water as a sole by-product, exhibiting superior sustainability and significant advancement to outperform the traditional amide production route in acidic or basic media with toxic by-products.
- Wang, Hai,Wang, Liang,Wang, Sai,Dong, Xue,Zhang, Jian,Xiao, Feng-Shou
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p. 401 - 406
(2018/08/11)
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- Nickel-catalyzed aminocarbonylation of aryl halides with carbamoylsilanes: efficient synthesis of secondary (primary) aromatic amides
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A nickel-catalyzed aminocarbonylation of aryl halides using carbamoylsilane as an amide source leading to corresponding secondary or primary aromatic amides has been developed, in which the methoxymethyl and benzyl were used as amino protecting group. The protocol tolerates a broad range of aryl halides bearing different functional groups to afford good yields of aryl amides under mild reaction conditions. The types and the relative positions of substituents on the aryl ring make a notable impact on the coupling efficiency. The plausible mechanism of nickel-catalyzed aminocarbonylation has been suggested.
- Chen, Jianxin,Chen, Wenwen,Wen, Xueping
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- Method for preparing acidamide from terminal olefin
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The invention belongs to the technical field of preparation of a fine chemical engineering product and synthesis of a medicine intermediate, and particularly relates to a method for preparing acidamide from terminal olefin. According to the method, the terminal olefin is used as a raw material; firstly, dibromohydantoin is added; stirring is performed; then, iodine and ammonium hydroxide or organic amine is added to obtain the corresponding acidamide. The method provided by the invention can be used for converting aromatic ring substituted terminal olefin; the method is also very effective onthe conversion of aliphatic terminal olefin into the acidamide. Compared with the prior art, the method has the advantages that the raw materials are cheap and can be easily obtained; the cost is low;the conditions are mild; the operation is easy; the toxicity of the used reagents is small; good substrate compatibility is realized; great cost and environmental-friendly advantages and wide application prospects are realized.
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Paragraph 0011; 0012; 0020
(2019/04/04)
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- Methyl-triflate-mediated dearylmethylation of: N -(arylmethyl)carboxamides via the retro-Mannich reaction induced by electrophilic dearomatization/rearomatization in an aqueous medium at room temperature
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We have developed a protocol for the dearylmethylation of N-(arylmethyl)carboxamides under metal-free conditions in an aqueous medium at room temperature. This protocol involves methyl triflate-mediated successive C-C and C-N bond cleavages (retro-Mannich reaction) induced by electrophilic dearomatization/rearomatization. The dearomatization/rearomatization strategy can be expected to inspire the development of novel transformations based on the C-C bond cleavage in an environmentally benign manner.
- Peng, Hui,Ma, Jinhui,Luo, Wenkun,Zhang, Guangwen,Yin, Biaolin
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supporting information
p. 2252 - 2256
(2019/05/17)
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- A room temperature next amine control lignin model molecular breaking method
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The invention relates to a room temperature next amine control lignin model molecular breaking method. The method adopts the 1 - aryl - 2 - [...] as lignin β - O - 4 model molecule, in under the action of the copper salt and an amine, is oxidized and broken C - C/C - O key; wherein a primary and secondary aliphatic amine control into aromatic amide and a phenolic compound, inorganic ammonia control generating α - one amide and phenolic compound, tertiary amine control into aromatic acid and phenol compounds. The testing process are as follows: the 1 - aryl - 2 - [...], amine compound with a copper salt in dimethyl sulfoxide in mixed, put in the pressure container, the charge air or oxygen after the replacement is closed, at room temperature, stirring the reaction 8 - 12 is H, can occur model molecular C - C/C - O bond breaking, to obtain aromatic amide, α - one amide, aromatic acid and phenol compounds. The mild conditions, cheap catalyst and oxidizing agent, various controllable reaction product, the reaction process is simple and easy to operate.
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Paragraph 0030; 0031; 0070; 0071
(2019/06/30)
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- Tandem Transformation of Aldoximes to N-Methylated Amides Using Methanol
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Tandem conversion of aldoximes to N-methylated amides with methanol in presence of a single Ru(II) catalyst is accomplished through the Ru(II)-mediated rearrangement followed by the reductive N-methylation. Employing this protocol, several aldoximes were directly transformed to the N-methylated amides using methanol. Kinetic experiments with H218O advocated that the aldoxime is acted as the nucleophile during the aldoxime to amide rearrangement process. Involvement of nitrile intermediate during this transformation is realized from the kinetic study. (Figure presented.).
- Paul, Bhaskar,Maji, Milan,Panja, Dibyajyoti,Kundu, Sabuj
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supporting information
p. 5357 - 5362
(2019/11/14)
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- Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
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A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
- Mukhopadhyay, Sushobhan,Batra, Sanjay
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supporting information
p. 14622 - 14626
(2018/09/21)
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- Amide Effects in C?H Activation: Noncovalent Interactions with L-Shaped Ligand for meta Borylation of Aromatic Amides
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A new concept for the meta-selective borylation of aromatic amides is described. It has been demonstrated that while esters gave para borylations, amides lead to meta borylations. For achieving high meta selectivity, an L-shaped bifunctional ligand has been employed and engages in an O???K noncovalent interaction with the oxygen atom of the moderately distorted amide carbonyl group. This interaction provides exceptional control for meta C?H activation/borylation.
- Bisht, Ranjana,Hoque, Md Emdadul,Chattopadhyay, Buddhadeb
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supporting information
p. 15762 - 15766
(2018/11/10)
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- Towards a Sequential One-Pot Preparation of 1,2,3-Benzotriazin-4(3H)-ones Employing a Key Cp*Co(III)-catalyzed C?H Amidation Step
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1,2,3-benzotriazin-4(3H)-one derivatives have been recognised for their potential application as pesticides and pharmaceuticals and new methodologies for their preparation, starting from readily accessible reagents would therefore be an attractive proposition. A wide range of differently substituted benzamides are readily available, which provide an excellent substrate scaffold for the application of direct C?H functionalization protocols. In this context, herein we report the use of a Cp*Co(III) catalyst for the amidation of these benzamides, using 1,4,2-dioxazol-5-ones as amidating agent. The isolable intermediate 2-acetamido benzamide products can thereafter be converted to the desired 1,2,3-benzotriazin-4(3H)-one derivatives through the use of tert-butyl nitrite under mild conditions. It was found to be possible to perform the second step with the crude reaction mixture obtained from the initial C?H amidation step, leading to the overall development of a facile one-pot procedure for the preparation of a range of substituted 1,2,3-benzotriazin-4(3H)-one derivatives, requiring only 5 hours of reaction time, which is also applicable on a gram scale. In addition, the key Cp*Co(III)-catalyzed C?H amidation step has been studied by DFT calculations in order to fully elucidate the mechanism. (Figure presented.).
- Chirila, Paula G.,Skibinski, Lauren,Miller, Keith,Hamilton, Alex,Whiteoak, Christopher J.
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supporting information
p. 2324 - 2332
(2018/04/30)
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- A carbonylation reaction of carbon monoxide in the method of preparing amide
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The invention belongs to the technical field of synthesis of amides, discloses a process for the carbonylation of carbon monoxide in the method of preparing amide, the method is to cheap and easy to obtain the halogenated aromatic hydrocarbon and organic amine compounds as the substrate of reaction, to carbon monoxide as carbonyl source, under light-struck, halogenated aromatic hydrocarbons are cracked to produce free radical, by free-radical addition process to obtain the amide compound. Compared with the traditional carbonylation reaction, the carbon monoxide pressure is extremely low, can react to the atmospheric pressure. This process does not need to rely on any metal catalyst of the booster, mild reaction conditions, environmental protection, with a shorter synthetic route and high utilization efficiency of the atoms, the reaction system with higher substrate tolerance, green sustainable light source as the driving force, the atom economy is high, application prospect.
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Paragraph 0024; 0025; 0026; 0027; 0028-0032; 0085-0086; 0145
(2018/07/30)
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- Synthesis of benzamides through direct condensation of carboxylic acids and amines in the presence of diatomite earth@IL/ZrCl4 under ultrasonic irradiation
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A green, rapid, mild and highly efficient pathway for the preparation of benzamide derivatives is reported. The reaction was performed through direct condensation of benzoic acids and amines under ultrasonic irradiation in the presence of Lewis acidic ionic liquid immobilized on diatomite earth (diatomite earth@IL/ZrCl4). A new, highly efficient and green solid acid catalyst was easily prepared via a two-step procedure and used as an effective reusable catalyst. The prepared catalyst provides active sites for the synthesis of benzamides. The advantages of this method are the use of a superior and recoverable catalyst, low reaction times, simple procedure, high-yielding and eco-friendly process and use of ultrasonic irradiation as a green and powerful technology. Since benzamides are used widely in the pharmaceutical, paper and plastic industries, and also as an intermediate product in the synthesis of therapeutic agents, the presented new synthetic methods for this type of compounds can be of considerable importance.
- Ahmadi, Masoumeh,Moradi, Leila,Sadeghzadeh, Masoud
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p. 7873 - 7889
(2018/09/27)
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