- Loss of benzaldehyde in the fragmentation of protonated benzoylamines: Benzoyl cation as a hydride acceptor in the gas phase
-
In electrospray ionization tandem mass spectrometry of protonated 1-benzoylamines (1-benzoylpiperadine, 1-benzoylmorpholine, and 1-benzoyl-4-methylpiperazine), the dominant fragmentation pathway was amide bond cleavage to form benzoyl cation and neutral amine. Meanwhile, in their fragmentations, an interesting loss of benzaldehyde (106?Da) was observed and identified to derive from hydride transfer reaction between the benzoyl cation and amine. A stepwise mechanism for loss of 106?Da (benzene and CO) could be excluded with the aid of deuterium labeling experiment. Theoretical calculations indicated that hydride transfers from amines (piperadine, morpholine, and 1-methylpiperazine) to benzoyl cation were thermodynamically permitted, and 1-methylpiperazine was the best hydride donor among the 3 amines. The mass spectrometric experimental results were consistent with the computational results. The relative abundance of the iminium cation (relative to the benzoyl cation) in the fragmentation of protonated 1-benzoyl-4-methylpiperazine was higher than that in the fragmentation of the other 2 protonated 1-benzoylamines. By comparing the fragmentations of protonated 1-benzyl-4-methylpiperazine and protonated 1-benzoyl-4-methylpiperazine and the energetics of their hydride transfer reactions, this study revealed that benzoyl cation was a hydride acceptor in the gas phase, but which was weaker than benzyl cation.
- Chai, Yunfeng,Shao, Yunlong,Wang, Lu,Wang, Lin
-
-
Read Online
- A new and efficient one-pot synthesis of aromatic alkynyl ketones from aromatic esters
-
The reaction of aromatic esters with alkynyllithiums in the presence of lithium morpholinide and BF3·OEt2 gave aromatic alkynyl ketones in good yield (78-87%).
- Yim, Sang Jun,Kwon, Chan Ho,An, Duk Keun
-
-
Read Online
- Synthesis of tertiary benzamides via Pd-catalyzed coupling of arylboronic esters and carbamoyl chlorides
-
Ortho-substituted arylboronic esters are efficiently coupled with carbamoyl chlorides under Pd-catalysis to give tertiary benzamides.
- Lysen, Morten,Kelleher, Susan,Begtrup, Mikael,Kristensen, Jesper Langgaard
-
-
Read Online
- Catalytic Formation of α-Aryl Ketones by C-H Functionalization with Cyclic Alkenyl Carbonates and One-Pot Synthesis of Isocoumarins
-
We report here a method for direct catalytic introduction of simple α-acylalkyl groups via rhodium-catalyzed C-H functionalization with cyclic alkenyl carbonates, synthetic equivalents to enolates bearing leaving groups. The reaction proceeded smoothly without using bases to give α-aryl ketones in high yields. Various nitrogen-containing aromatic rings and amide groups serve as directing groups. 3-Substituted isocoumarins can also be prepared by one-pot C-H functionalization/cyclization.
- Hara, Yusuke,Onodera, Shunsuke,Kochi, Takuya,Kakiuchi, Fumitoshi
-
-
Read Online
- Silica nanosphere-supported palladium(II) furfural complex as a highly efficient and recyclable catalyst for oxidative amination of aldehydes
-
The present work reports the fabrication of a novel and highly efficient silica nanospheres-based palladium catalyst (SiO2@APTES@Pd-FFR) via immobilization of a palladium complex onto silica nanospheres functionalized with 3-aminopropyltriethoxysilane (APTES), and its catalytic application for the oxidative amination of aldehydes to yield commercially important amides. The structure of the nano-catalyst was confirmed by Solid-state 13C CPMAS and 29Si CPMAS NMR spectroscopy, Brunauer-Emmett-Teller (BET) surface area analysis, Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray fluorescence spectroscopy (ED-XRF), Atomic absorption spectroscopy (AAS), Transmission electron microscopy (TEM) and elemental analysis. The nano-catalyst was found to be highly effective for the oxidative amination of aldehydes using hydrogen peroxide as an environmentally benign oxidant to give amides. The effect of various reaction parameters such as temperature, amount of catalyst, reaction time, type of solvent, oxidant used, substrate to oxidant ratio etc. have been demonstrated to achieve high catalytic efficacy. Moreover, this nanostructured catalyst could be recovered with simplicity and reused for several cycles without any significant loss in its catalytic activity. In addition, the stability of the reused nano-catalyst was proved by FT-IR and HRTEM techniques. It is worth noting that the features of mild reaction conditions, simple work-up procedure, high product yield, no use of toxic organic solvents, high turn-over frequency (TOF), and easy recovery and reusability of the present quasi-homogeneous nano-catalyst make this protocol an attractive alternative to the existing catalytic methods for the oxidative amination of aldehydes to furnish industrially important amides. The Royal Society of Chemistry 2014.
- Sharma,Sharma, Shivani
-
-
Read Online
- The magnetic graphene oxide/NHC catalyzed aerobic direct amidation and cross-dehydrogenative coupling of aldehydes
-
In this paper, the synthesis of a novel imidazolium based N-heterocyclic carbene (NHC) containing imidazopyridine substitutes using a three-component reaction is described. This compound was immobilized on magnetic graphene oxide (GO) to make a heterogeneous catalyst for the direct aerobic amidation of benzaldehyde derivatives under solvent-free conditions, as well as the intra-and intermolecular cross dehydrogenative coupling of aldehydes. In addition, the catalytic activity of the NHC catalyst was homogeneously studied in the presence of Fe3O4 nanoparticles under the same conditions, and showed good activity with lower yields than the heterogeneous catalyst.
- Sepahvand, Heshmatollah,Ghasemi, Elnaz,Sharbati, Mohammad,Mohammadi, Melika Sadat,Arshadi Pirlar, Maghsoud,Shahverdizadeh, Gholam Hossein
-
-
Read Online
- Development of palladium catalysts immobilized on supported phosphonium ionic liquid phases
-
The application of heterogeneous palladium catalysts supported on phosphonium ion modified silica was investigated in aminocarbonylation reactions of aryl iodides. In contrast to catalysts immobilized on supports decorated with imidazolium ions, the application of phosphonium type supported ionic liquid phases made it possible to carry out double carbonylation with good selectivity in apolar toluene which led to a considerable decrease in the amount of leached palladium. An even better stabilization of the palladium catalyst could be achieved by introducing dicationic organic moieties incorporating both imidazolium and phosphonium ions on the surface of the support. At the same time, the former catalyst, obtained from the supported phosphonium ionic liquid phase was found to be superior in monocarbonylations. The amide products were obtained in good yields by the proper choice of the reaction conditions, such as reaction temperature and pressure and that of the base.
- Urbán, Béla,Skoda-F?ldes, Rita
-
-
Read Online
- Synthesis of sterically hindered peptide analogs using diphenyl phosphite as the coupling reagent
-
Some model sterically hindered peptide analogs were synthesized with various yields using diphenyl phosphite as the coupling reagent under mild conditions. The experimental procedure is straightforward and the products are easily isolated. This method may be convenient and efficient for the synthesis of hindered peptides.
- Yang, Ting,Lin, Changxue,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
-
-
Read Online
- N-BENZOYL O,O-DIALKYL PHOSPHORANILIDATES: REACTION WITH O- AND N-NUCLEOPHILES
-
Solvolysis of mixed phosphoric-carboxylic N-phenylimides occurs with exclusive attack of nucleophiles at the carbonyl carbon centre and is accompanied by phosphoryl N->O migration.
- Baraniak, Janina,Stec, Wojciech J.
-
-
Read Online
- Synthesis and new application of green and recyclable cyclic poly(L -lactide)-clay hybrid
-
We report on the application of biodegradable cyclic poly(L-lactide) (PLLA) as new stabilizer; synthesis and application of a cyclic PLLA-clay hybrid material as recyclable catalyst support. Cyclic PLLAs were used to stabilize palladium nanoparticles synthesized by a wet chemical method. It was found that the palladium particles were smaller with cyclic PLLA stabilizer (~5-10 nm) than the particles obtained from linear PLLA. The cyclic PLLA-clay hybrid was prepared by a zwitterionic ring-opening polymerization catalyzed by in situ-generated N-heterocyclic carbene catalyst. Palladium (0) nanoparticles were supported and well dispersed on the cyclic PLLA-clay hybrid to form a new nanocomposite. The nanocomposite was found to be a highly efficient and recyclable catalyst for the aminocarbonylation reactions of aryl halides with various amines.
- Prasad, Aitha Vishwa,Biying, Algin Oh,Ling, Woo Yuan,Stubbs, Ludger Paul,Zhu, Yinghuai
-
-
Read Online
- Acylation of piperidine and morpholine with phenyl benzoates in the mixtures water-2-propanol and water-dioxane
-
Kinetics of acylation of piperidine and morpholine with 4-nitro- and 2,6-dinitrophenyl benzoates was studied in binary systems water-2-propanol and water-dioxane. Structural and energy characteristics of solvate complexes of morpholine and piperidine with the components of the mixed solvents were calculated. Kinetic regularities of acylation are considered from the viewpoint of specific solvation of amines.
- Kochetova,Kalinina,Kuritsyn,Kustova
-
-
Read Online
- Samarium-mediated mild and facile method for the synthesis of amides
-
Samarium-mediated facile method for the formation of amide bonds by the reaction of acyl chlorides and amines is described. The reaction afforded high yields of the desired amides under mild and neutral conditions.
- Shi, Feng,Li, Jian,Li, Chunju,Jia, Xueshun
-
-
Read Online
- Pd-PEPPSI: A general Pd-NHC precatalyst for Buchwald-Hartwig cross-coupling of esters and amides (transamidation) under the same reaction conditions
-
Amides are of fundamental interest in many fields of chemistry involving organic synthesis, chemical biology and biochemistry. Here, we report the first catalytic Buchwald-Hartwig coupling of both common esters and amides by highly selective C(acyl)-X (X = O, N) cleavage to rapidly access aryl amide functionality via a cross-coupling strategy. Reactions are promoted by versatile, easily prepared, well-defined Pd-PEPPSI type precatalysts, and proceed in good to excellent yields and with excellent chemoselectivity for the acyl bond cleavage. The method is user friendly because it employs commercially-available, moisture- and air-stable precatalysts. Notably, for the first time we demonstrate selective C(acyl)-N and C(acyl)-O cleavage/Buchwald-Hartwig amination under the same reaction conditions, which allows for streamlining amide synthesis by avoiding restriction to a particular acyl metal precursor. Of broad interest, this study opens the door to using a family of well-defined Pd(ii)-NHC precatalysts bearing pyridine "throw-away" ligands for the selective C(acyl)-amination of bench-stable carboxylic acid derivatives.
- Shi, Shicheng,Szostak, Michal
-
-
Read Online
- High-Loading Crystals of Tetraaryladamantanes and the Uptake and Release of Aromatic Hydrocarbons from the Gas Phase
-
Recently, a tetraphenyladamantane octamethylether was shown to encapsulate a wide range of small molecules in its crystals. Uptake and release from the liquid phase were demonstrated, and crystalline inclusion complexes were prepared that act as formulation for obnoxious reagents. However, fewer than two equivalents of guest molecules were found within the crystal structures. Here we report the synthesis of 1,3,5,7-tetrakis(2,4-diethoxyphenyl)adamantane (TEO) and twelve X-ray crystal structures that contain up to 3.5 equivalents of guest molecules. After crystallization and drying, TEO gives a material that absorbs 30 wt % of p-xylene reversibly through the gas phase, and releases it again at 55 °C, suggesting that it may be used for the capture and release of aromatic hydrocarbons.
- Alexandre, Pierre-Emmanuel,Schwenger, Alexander,Frey, Wolfgang,Richert, Clemens
-
-
Read Online
- Ionic Complexes of Tetra- and Nonanuclear Cage Copper(II) Phenylsilsesquioxanes: Synthesis and High Activity in Oxidative Catalysis
-
Herein, we describe an approach to cage metallasilsesquioxanes by self-assembly with 1,2-bis(diphenylphosphino)ethane as a key reactant. This approach allowed us to achieve a unique family of complexes that includes anionic tetra- and nonanuclear cage copper(II) sodium silsesquioxane and cationic copper(I) 1,2-bis(diphenylphosphino)ethane components. Additional representatives of this intriguing metallasilsesquioxane family (Cu9Na6 and Cu9Na3Cs3) were obtained through the replacement of the original ethanol-based reaction medium by DMSO. The fascinating structural peculiarities of all products were established by using XRD and topological studies. Initial tests for the application of the synthesized complexes as catalysts revealed their very high activity in the homogeneous oxidation of alkanes and alcohols to produce alkyl hydroperoxides, ketones, and amides.
- Bilyachenko, Alexey N.,Kulakova, Alena N.,Levitsky, Mikhail M.,Korlyukov, Alexander A.,Khrustalev, Victor N.,Vologzhanina, Anna V.,Titov, Aleksei A.,Dorovatovskii, Pavel V.,Shul'pina, Lidia S.,Lamaty, Frédéric,Bantreil, Xavier,Villemejeanne, Beno?t,Ruiz, Cindy,Martinez, Jean,Shubina, Elena S.,Shul'pin, Georgiy B.
-
-
Read Online
- Cage-like copper(II) silsesquioxanes: Transmetalation reactions and structural, quantum chemical, and catalytic studies
-
The transmetalation of bimetallic copper-sodium silsesquioxane cages, namely, [(PhSiO1.5)10(CuO)2(NaO0.5)2] ( Cooling Tower ; 1), [(PhSiO1.5)12(CuO)4(NaO0.5)4] ( Globule ; 2), and [(PhSiO1.5)6(CuO)4(NaO0.5)4(PhSiO1.5)6] ( Sandwich ; 3), resulted in the generation of three types of hexanuclear cylinder-like copper silsesqui- oxanes, [(PhSiO1.5)12(CuO)6(C4H9OH)2(C2H5OH)6] (4), [(PhSiO1.5)12(CuO)6(C4H8O2)4(PhCN)2(MeOH)4] (5), and [(PhSiO1.5)12(CuO)6(NaCl)(C4H8O2)12(H2O)2] (6). The products show a prominent solvating system-structure dependency, as determined by X-ray diffraction. Topological analysis of cages 1-6 was also performed. In addition, DFT theory was used to examine the structures of the Cooling Tower and Cylinder compounds, as well as the spin density distributions. Compounds 1, 2, and 5 were applied as catalysts for the direct oxidation of alcohols and amines into the corresponding amides. Compound 6 is an excellent catalyst in the oxidation reactions of benzene and alcohols.
- Bilyachenko, Alexey N.,Dronova, Marina S.,Yalymov, Alexey I.,Lamaty, Frédéric,Bantreil, Xavier,Martinez, Jean,Bizet, Christelle,Shul'Pina, Lidia S.,Korlyukov, Alexander A.,Arkhipov, Dmitry E.,Levitsky, Mikhail M.,Shubina, Elena S.,Kirillov, Alexander M.,Shul'Pin, Georgiy B.
-
-
Read Online
- Iron-Catalyzed Amide Formation from the Dehydrogenative Coupling of Alcohols and Secondary Amines
-
The five-coordinate iron(II) hydride complex (iPrPNP)Fe(H)(CO) (iPrPNP = N[CH2CH2(PiPr2)]2) selectively catalyzes the dehydrogenative intermolecular coupling of alcohols and secondary amines to form tertiary amides. This is the most productive base-metal catalyst for dehydrogenative amidation reported to date, in some cases achieving up to 600 turnovers. The catalyst works well for sterically undemanding amines and alcohols or cyclic substrates and is particularly effective in the synthesis of formamides from methanol. However, the catalyst performance declines rapidly with the incorporation of large substituents on the amine or alcohol substrate. Variable-temperature NMR spectroscopic studies suggest that the catalyst resting state is an off-cycle iron(II) methoxide species, (iPrPN(H)P)Fe(H)(OCH3)(CO), resulting from addition of methanol across the Fe-N bond of (iPrPNP)Fe(H)(CO). This reversibly formed iron(II) methoxide complex is favored at mild temperatures but eliminates methanol upon heating.
- Lane, Elizabeth M.,Uttley, Katherine B.,Hazari, Nilay,Bernskoetter, Wesley
-
-
Read Online
- A comprehensive study on the effect of preparation methods for Au-core@shell silica materials in room temperature oxidative amide formation
-
Core-shell silica comprising mesoporous SiO2 shell and solid SiO2 core (SiO2@mSiO2) was utilized as catalytic support to prepare highly active and efficient Au-SiO2@mSiO2 catalysts for room temperature catalysis. Results showed that the mesoporous shell significantly contributed to the high surface area of SiO2@mSiO2. Au nanocatalysts prepared by different methods (impregnation, IM and deposition-precipitation-DP) exhibited remarkably different structural properties. Au-SiO2@mSiO2 catalysts exhibited excellent catalytic activity and high stability. Conversion could reach ca. 54% in the amidation of benzaldehyde and morpholine, with a complete selectivity to the target amide product at room temperature. This journal is
- Huang, Jiale,Zhang, Mingyu,Wang, Jing,Hu, Xijun,Luque, Rafael,Lam, Frank L. Y.
-
-
Read Online
- TBAI-catalyzed C–N bond formation through oxidative coupling of benzyl bromides with amines: a new avenue to the synthesis of amides
-
A new green approach for the synthesis of amide through TBAI-catalyzed oxidative coupling of benzyl bromides with amine was developed in the presence of tert-butyl hydroperoxide (TBHP) as an oxidant. Various electron-donating and withdrawing groups containing benzyl bromides and various amines, were subjected to the reaction and transformed to the corresponding amide in good to excellent yields.
- Kumar, Dhirendra,Maury, Suresh Kumar,Kumari, Savita,Kamal, Arsala,Singh, Himanshu Kumar,Singh, Sundaram,Srivastava, Vandana
-
supporting information
p. 424 - 432
(2022/02/09)
-
- Effect of Precatalyst Oxidation State in C-N Cross-Couplings with 2-Phosphinoimidazole-Derived Bimetallic Pd(I) and Pd(II) Complexes
-
We report the catalytic activity of two phosphinoimidazole-derived bimetallic palladium complexes in Pd-catalyzed amination reactions. Our studies demonstrate that the starting oxidation state (Pd(I) or Pd(II)) of the dimeric complex has a significant effect on the efficiency of the catalytic reaction. The corresponding Pd(I) complex shows higher reactivity in Buchwald-Hartwig aminations, while the Pd(II) complex is much more reactive in carbonylative amination reactions. These new dimeric palladium complexes provide good to excellent reactivity and yields in the amination reactions tested.
- Martinez, Erin E.,Moreno, Mariur Rodriguez,Barksdale, Caleb A.,Michaelis, David J.
-
supporting information
p. 2763 - 2767
(2021/08/27)
-
- Direct Amidation of Esters by Ball Milling**
-
The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This direct synthesis platform has been applied to the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals as well as the gram-scale synthesis of an active pharmaceutical, all in the absence of a reaction solvent.
- Barreteau, Fabien,Battilocchio, Claudio,Browne, Duncan L.,Godineau, Edouard,Leitch, Jamie A.,Nicholson, William I.,Payne, Riley,Priestley, Ian
-
supporting information
p. 21868 - 21874
(2021/09/02)
-
- A practical and sustainable protocol for direct amidation of unactivated esters under transition-metal-free and solvent-free conditions
-
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)
-
- Manganese Catalyzed Direct Amidation of Esters with Amines
-
The transition metal catalyzed amide bond forming reaction of esters with amines has been developed as an advanced approach for overcoming the shortcomings of traditional methods. The broad scope of substrates in transition metal catalyzed amidations remains a challenge. Here, a manganese(I)-catalyzed method for the direct synthesis of amides from a various number of esters and amines is reported with unprecedented substrate scope using a low catalyst loading. A wide range of aromatic, aliphatic, and heterocyclic esters, even in fatty acid esters, reacted with a diverse range of primary aryl amines, primary alkyl amines, and secondary alkyl amines to form amides. It is noteworthy that this approach provides the first example of the transition metal catalyzed amide bond forming reaction from fatty acid esters and amines. The acid-base mechanism for the manganese(I)-catalyzed direct amidation of esters with amines was elucidated by DFT calculations.
- Fu, Zhengqiang,Wang, Xinghua,Tao, Sheng,Bu, Qingqing,Wei, Donghui,Liu, Ning
-
supporting information
p. 2339 - 2358
(2021/02/03)
-
- Zirconium Oxide-Catalyzed Direct Amidation of Unactivated Esters under Continuous-Flow Conditions
-
A sustainable and environmentally benign direct amidation reaction of unactivated esters with amines has been developed in a continuous-flow system. A commercially available amorphous zirconium oxide was found to be an efficient catalyst for this reaction. While the typical amidation of esters with amines requires a stoichiometric amount of a promoter or metal activator, the present continuous-flow method enabled the direct amidation reaction under additive-free conditions with an extensive diversity towards various functional groups. High yields of the products were obtained with a nearly equimolar proportion of starting materials to reduce byproduct formation, which renders this process applicable for use in a sequential-flow system. (Figure presented.).
- Rashed, Md. Nurnobi,Masuda, Koichiro,Ichitsuka, Tomohiro,Koumura, Nagatoshi,Sato, Kazuhiko,Kobayashi, Shū
-
p. 2529 - 2535
(2021/02/01)
-
- 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 0023-0024; 0025-0026
(2021/05/12)
-
- Benzyne-Mediated Esterification Reaction
-
A benzyne-mediated esterification of carboxylic acids and alcohols under mild conditions has been realized, which is made possible via a selective nucleophilic addition of carboxylic acid to benzyne in the presence of alcohol. After a subsequent transesterification with alcohol, the corresponding esters can be produced efficiently. This benzyne-mediated protocol can be used on the modification of Ibuprofen, cholesterol, estradiol, and synthesis of nandrolone phenylpropionate. In addition, benzyne can also be used to promote lactonization and amidation reaction.
- Li, Yang,Shi, Jiarong,Zhao, Jinlong
-
supporting information
p. 7274 - 7278
(2021/10/01)
-
- Method for preparing amide compound by photocatalysis of nitrogen-containing heterocyclic compound
-
The invention provides a method for preparing an amide compound by photocatalysis of a nitrogen-containing heterocyclic compound. The method comprises the following steps: mixing the nitrogen-containing heterocyclic compound, organic carboxylic acid and tetrahalomethane in a solvent, adding a catalyst, and reacting under the illumination condition to prepare the amide compound. According to the invention, the organic carboxylic acid, the nitrogen-containing heterocyclic compound containing reactive hydrogen on nitrogen atoms and the tetrahalomethane are used as raw materials, so the raw materials are wide in source, low in cost and high in safety, and large-scale production is facilitated; the halogen simple substance is co-produced in the reaction process, the added value is high, a large amount of waste is prevented from being generated, and the method has high atom economy and environmental friendliness; light conditions are adopted to replace traditional heating and high-pressure conditions, the reaction conditions are mild, environmental pollution is reduced, and the reaction cost is reduced; the method has the advantages of good substrate applicability, mild process conditions, environmental protection, simple process, simple and feasible operation method, and facilitation of popularization and application.
- -
-
Paragraph 0079-0080; 0093; 0094
(2021/06/06)
-
- Nickel-Catalyzed Amination of Aryl Chlorides with Amides
-
A nickel-catalyzed amination of aryl chlorides with diverse amides via C-N bond cleavage has been realized under mild conditions. A broad substrate scope with excellent functional group tolerance at a low catalyst loading makes the protocol powerful for synthesizing various aromatic amines. The aryl chlorides could selectively couple to the amino fragments rather than the carbonyl moieties of amides. Our protocol complements the conventional amination of aryl chlorides and expands the usage of inactive amides.
- Li, Jinpeng,Huang, Changyu,Wen, Daheng,Zheng, Qingshu,Tu, Bo,Tu, Tao
-
supporting information
p. 687 - 691
(2021/01/09)
-
- Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
-
Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
- Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
-
supporting information
p. 5022 - 5037
(2021/05/04)
-
- Rhoda-Electrocatalyzed Bimetallic C?H Oxygenation by Weak O-Coordination
-
Rhodium-electrocatalyzed arene C?H oxygenation by weakly O-coordinating amides and ketones have been established by bimetallic electrocatalysis. Likewise, diverse dihydrooxazinones were selectively accessed by the judicious choice of current, enabling twofold C?H functionalization. Detailed mechanistic studies by experiment, mass spectroscopy and cyclovoltammetric analysis provided support for an unprecedented electrooxidation-induced C?H activation by a bimetallic rhodium catalysis manifold.
- Tan, Xuefeng,Massignan, Leonardo,Hou, Xiaoyan,Frey, Johanna,Oliveira, Jo?o C. A.,Hussain, Masoom Nasiha,Ackermann, Lutz
-
supporting information
p. 13264 - 13270
(2021/05/06)
-
- Hydrosilylative reduction of primary amides to primary amines catalyzed by a terminal [Ni-OH] complex
-
A terminal [Ni-OH] complex1, supported by triflamide-functionalized NHC ligands, catalyzes the hydrosilylative reduction of a range of primary amides into primary amines in good to excellent yields under base-free conditions with key functional group tolerance. Catalyst1is also effective for the reduction of a variety of tertiary and secondary amides. In contrast to literature reports, the reactivity of1towards amide reduction follows an inverse trend,i.e., 1° amide > 3° amide > 2° amide. The reaction does not follow a usual dehydration pathway.
- Bera, Jitendra K.,Pandey, Pragati
-
supporting information
p. 9204 - 9207
(2021/09/20)
-
- Metal-Free Selective Modification of Secondary Amides: Application in Late-Stage Diversification of Peptides
-
Here we solve a long-standing challenge of the site-selective modification of secondary amides and present a simple two-step, metal-free approach to selectively modify a particular secondary amide in molecules containing multiple primary and secondary amides. Density functional theory (DFT) provides insight into the activation of C-N bonds. This study encompasses distinct chemical advances for late-stage modification of peptides thus harnessing the amides for the incorporation of various functional groups into natural and synthetic molecules.
- Adebomi, Victor,Sriram, Mahesh,Streety, Xavier,Raj, Monika
-
p. 6189 - 6193
(2021/08/01)
-
- Fluorinated solvent-assisted photocatalytic aerobic oxidative amidation of alcoholsviavisible-light-mediated HKUST-1/Cs-POMoW catalysis
-
Considering the irreplaceable importance of photocatalytic functionalization reactions and the widespread attention paid to the use of metal-organic frameworks, especially their modified variants, for this purpose in recent years, different types of HKUST-1/POMoW composites were prepared through the immobilization of a series of Keggin-type polyoxometalates (POMs; POW = H3PW12O40, POMo = H3PMo12O40, and POMoW = H3PMo6W6O40) on HKUST-1 as a metal-organic framework (HKUST-1; Cu3(1,3,5-benzenetricarboxilicacid)2). Then, to produce HKUST-1/Cs-POM, the substitution of H+cations with Cs+ones as counter cations was carried out. The prepared composites were fully characterized with the PXRD (powder X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy), BET and BJH (sorption of N2), TGA (thermo-gravimetric analysis), SEM (scanning electron microscopy), EDX (energy dispersive X-ray), TEM (transmission electron microscopy), UV-vis DRS (diffuse reflectance UV-vis spectroscopy), photoluminescence (PL) spectroscopy and ICP-AES (inductively coupled plasma atomic emission spectroscopy) techniques. The great importance?of the amide functional group and the attractiveness of photocatalytic oxidative functionalization?reactions led us to study the formation of this functional group using the prepared catalytic system in line with our previous research in this field. The HKUST-1/Cs-POMoW composite showed a raised photocatalytic performance compared to the discrete components, HKUST-1 and Cs-POMs, in aerobic oxidative amidation of alcohols under illumination with visible light, owing to the presence of catalytically active Cs-POMs deposited on the MOF particles. Besides, the combination of composite components mitigated the recombination rate of the electron-hole pairs, raising its photocatalytic activity. The attractiveness of fluorine solvents for oxidation reactions has led to the study of their role in the efficiency of oxidative amidation of alcohols and their significant effect on the efficiency of the process has been confirmed. The Cu-MOF/POM catalyst showed excellent stability during the reaction, and no significant decrease in its ability was observed during five consecutive cycles.
- Azarkhosh, Zahra,Heydari, Akbar,Karimi, Meghdad,Mahjoub, Alireza,Mohebali, Haleh,Sadeghi, Samira,Safarifard, Vahid
-
supporting information
p. 14024 - 14035
(2021/08/16)
-
- NaI-mediated oxidative amidation of benzyl alcohols/aromatic aldehydes to benzamides via electrochemical reaction
-
In this research, we have developed a mild electrochemical process for oxidative amidation of benzyl alcohols/aromatic aldehydes with cyclic amines into the corresponding benzamides. This electroorganic synthetic method proceeds using NaI as a redox mediator under ambient temperature in undivided cell, providing more than 25 examples of amide products in moderate to good yields. The benefits of this reaction include one-pot synthesis, open air condition, proceed in aqueous media and no requirement of external conducting salt, base and oxidant.
- Rerkrachaneekorn, Tanawat,Tankam, Theeranon,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
-
supporting information
(2021/04/15)
-
- Chromium-catalyzed ligand-free amidation of esters with anilines
-
Amides are important structural motifs in pharmaceutical and agrochemical chemistry because of the intriguing biological active properties. We report here the amidation of commercially available esters with anilines that was promoted by low-cost and air-stable chromium(III) pre-catalyst combined with magnesium, providing access to amides. This reaction occurs without the use of external ligands in a simple operation. Mechanistic studies indicate that a reactive aminated Cr species responsible for the amidation can be considered, which may be formed by reaction of low-valent Cr with aniline followed by reduction with hydrogen evolution.
- Chen, Changpeng,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
-
supporting information
p. 762 - 766
(2021/04/14)
-
- Copper and N-Heterocyclic Carbene-Catalyzed Oxidative Amidation of Aldehydes with Amines
-
A one-pot two-step oxidative process has been developed for the tert-butyl hydroperoxide mediated transformation of aldehydes and amines into amides catalyzed by copper(I) iodide and an N-heterocyclic carbene. The process is additive-free and does not require the amine to be transformed into its hydrochloride salts. The method is simple and practicable, has a broad substrate scope, and uses economical, feasible, and abundant reagents.
- Singh, Ashmita,Narula, Anudeep Kumar
-
supporting information
p. 718 - 722
(2021/02/26)
-
- Catalytic N-Acylation of Cyclic Amines by Arylglyoxylic Acids via Radical-Radical Cross-Coupling
-
A methodical mechanistic investigation allowed for the catalytic N-acylation of secondary cyclic amine counterparts by arylglyoxylic acids through radical-radical coupling. The reaction proceeds via a twofold SET-promoted Cu(I)/Cu(II) catalytic cycle under mild conditions. An analogous reaction variant allows for the N-acylation in a one-pot fashion directly starting from a secondary cyclic amine even in the presence of a second amine or hydroxy group.
- Bhadra, Sukalyan,Gupta, Aniket,Kumar Singh, Anupam,Rahaman, Ajijur
-
supporting information
p. 2198 - 2202
(2021/07/22)
-
- Pd-Catalyzed Oxidative Aminocarbonylation of Arylboronic Acids with Unreactive Tertiary Amines via C-N Bond Activation
-
An efficient synthesis of tertiary amides from aryl boronic acids and inert tertiary amines through the oxidative carbonylation via C(sp3)-N bond activation is presented. This protocol significantly restricts the homocoupling biarylketone product. It involves the use of a homogeneous PdCl2/CuI catalyst and a heterogeneous Pd/C based catalyst, which promotes C(sp3)-N bond activation of tertiary amines with aryl boronic acids. This process represents a ligand-free, base-free, and recyclable catalyst along with an ideal oxidant like molecular oxygen.
- Kolekar, Yuvraj A.,Bhanage, Bhalchandra M.
-
p. 14028 - 14035
(2021/05/29)
-
- N -Heterocyclic carbene (NHC) catalyzed amidation of aldehydes with amines via the tandem N -hydroxysuccinimide ester formation
-
A facile method for the amidation of aldehydes by a cascade approach was developed. This methodology, reported for the first time, uses a N-heterocyclic carbene (NHC) as the catalyst, and N-hydroxysuccinimide (NHS) mediated synthesis of amides utilising TBHP as the oxidant. Various substituted aldehydes reacted smoothly with NHS giving the corresponding active esters in moderate to good yields, which facilely converted into amides in one pot. In addition, the drug moclobemide was synthesized to represent the practical utility of the developed methodology. This journal is
- Singh, Ashmita,Narula
-
supporting information
p. 7486 - 7490
(2021/05/13)
-
- One-Pot Synthesis of Tertiary Amides from Organic Trichlorides through Oxygen Atom Incorporation from Air by Convergent Paired Electrolysis
-
A convergent paired electrolysis catalyzed by a B12 complex for the one-pot synthesis of a tertiary amide from organic trichlorides (R-CCl3) has been developed. Various readily available organic trichlorides, such as benzotrichloride and its derivatives, chloroform, dichlorodiphenyltrichloroethane (DDT), trichloro-2,2,2-trifluoroethane (CFC-113a), and trichloroacetonitrile (CNCCl3), were converted to amides in the presence of tertiary amines through oxygen incorporation from air at room temperature. The amide formation mechanism in the paired electrolysis, which was mediated by a cobalt complex, was proposed.
- Luo, Zhongli,Imamura, Kenji,Shiota, Yoshihito,Yoshizawa, Kazunari,Hisaeda, Yoshio,Shimakoshi, Hisashi
-
p. 5983 - 5990
(2021/05/04)
-
- A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
-
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
- Huang, Binbin,Guo, Lin,Xia, Wujiong
-
supporting information
p. 2095 - 2103
(2021/03/26)
-
- Carboxyboronate as a Versatile In Situ CO Surrogate in Palladium-Catalyzed Carbonylative Transformations
-
The application of carboxy-MIDA-boronate (MIDA=N-methyliminodiacetic acid) as an in situ CO surrogate for various palladium-catalyzed transformations is described. Carboxy-MIDA-boronate was previously shown to be a bench-stable boron-containing building block for the synthesis of borylated heterocycles. The present study demonstrates that, in addition to its utility as a precursor to heterocycle synthesis, carboxy-MIDA-boronate is an excellent in situ CO surrogate that is tolerant of reactive functionalities such as amines, alcohols, and carbon-based nucleophiles. Its wide functional-group compatibility is highlighted in the palladium-catalyzed aminocarbonylation, alkoxycarbonylation, carbonylative Sonogashira coupling, and carbonylative Suzuki–Miyaura coupling of aryl halides. A variety of amides, esters, (hetero)aromatic ynones, and bis(hetero)aryl ketones were synthesized in good-to-excellent yields in a one-pot fashion.
- Tien, Chieh-Hung,Trofimova, Alina,Holownia, Aleksandra,Kwak, Branden S.,Larson, Reed T.,Yudin, Andrei K.
-
supporting information
p. 4342 - 4349
(2020/12/25)
-
- UV-Light-Induced N-Acylation of Amines with α-Diketones
-
Herein, we develop a mild method for N-acylation of primary and secondary amines with α-diketones induced by ultraviolet (UV) light. Forty-six examples with various functional groups are explored at room temperature with irradiation by three 26 W UV lamps (350-380 nm). The yield reaches 97%. The gram scale experiment product yield is 76%. Moreover, this system can be applied to the synthesis of several amino acid derivatives. Mechanistic studies show that benzoin is generated in situ from benzil under UV irradiation.
- Xu, Zhihui,Yang, Tianbao,Tang, Niu,Ou, Yifeng,Yin, Shuang-Feng,Kambe, Nobuaki,Qiu, Renhua
-
supporting information
p. 5329 - 5333
(2021/07/21)
-
- 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.
- An, Duk Keun,Jaladi, Ashok Kumar,Kim, Hyun Tae,Yi, Jaeeun
-
supporting information
(2021/11/17)
-
- Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides
-
We report a new visible-light-mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)2(dtb-bpy)]+ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible with aliphatic and aromatic amines, shows high functional-group tolerance, and enables the late-stage amidation of complex natural products.
- Connell, Timothy U.,Forni, José A.,Micic, Nenad,Polyzos, Anastasios,Weragoda, Geethika
-
supporting information
p. 18646 - 18654
(2020/08/21)
-
- Synthetic method for preparing amide compounds through co-catalysis of niobium pentachloride and ionic liquid
-
The invention relates to a synthetic method for preparing amide compounds through co-catalysis of niobium pentachloride and ionic liquid. The preparation method is characterized by comprising the following steps: weighing organic carboxylic acid, organic amine, niobium pentachloride, ionic liquid and a molecular sieve, adding the materials into a reactor, adding an organic solvent, and reacting for 6-24 hours at the reaction temperature of 70-110 DEG C to obtain a corresponding amide product. The molar ratio of the organic carboxylic acid to the organic amine to the niobium pentachloride to the ionic liquid is 1:(1-3):(0.01-1):(0.05-1); wherein the mass ratio of the organic carboxylic acid to the molecular sieve is 1: (0.2-1). According to the method, the substrate range is expanded, the reaction yield is high (95% or above), the catalyst dosage is small, the atom economy is high, the catalyst is cheap and easy to obtain, the production cost can be greatly reduced, and the method is suitable for industrial production.
- -
-
Paragraph 0059-0061
(2020/07/13)
-
- Tris(o-phenylenedioxy)cyclotriphosphazene as a Promoter for the Formation of Amide Bonds between Aromatic Acids and Amines
-
The atom-efficient formation of amide bonds has emerged as a top-priority research field in organic synthesis, as amide bonds constitute the backbones of proteins and represent an important structural motif in drug molecules. Currently, the increasing demand for novel discoveries in this field has focused substantial attention on this challenging subject. Herein, the degradable 1,3,5-triazo-2,4,6-triphosphorine (TAP) motif is presented as a new condensation system for the dehydrative formation of amide bonds between diverse combinations of aromatic carboxylic acids and amines. The underlying reaction mechanism was investigated, and potential catalyst intermediates were characterized using 31 P NMR spectroscopy and ESI mass spectrometry.
- Movahed, Farzaneh Soleymani,Sawant, Dinesh N.,Bagal, Dattatraya B.,Saito, Susumu
-
p. 3253 - 3262
(2020/11/02)
-
- A practical catalytic reductive amination of carboxylic acids
-
We report reductive alkylation reactions of amines using carboxylic acids as nominal electrophiles. The two-step reaction exploits the dual reactivity of phenylsilane and involves a silane-mediated amidation followed by a Zn(OAc)2-catalyzed amide reduction. The reaction is applicable to a wide range of amines and carboxylic acids and has been demonstrated on a large scale (305 mmol of amine). The rate differential between the reduction of tertiary and secondary amide intermediates is exemplified in a convergent synthesis of the antiretroviral medicine maraviroc. Mechanistic studies demonstrate that a residual 0.5 equivalents of carboxylic acid from the amidation step is responsible for the generation of silane reductants with augmented reactivity, which allow secondary amides, previously unreactive in zinc/phenylsilane systems, to be reduced.
- Andrews, Keith G.,Denton, Ross M.,Hirst, David J.,Stoll, Emma L.,Tongue, Thomas,Valette, Damien
-
p. 9494 - 9500
(2020/10/02)
-
- Rational design of fluorescent probes for targeted: In vivo nitroreductase visualization
-
Nitroreductase (NTR) has been recognized as a biomarker for identifying the hypoxic status of cancers. Therefore, it is of high scientific interest to design effective fluorescent probes for tracking NTR activity. However, studies on elucidation of the structure-performance relationship of fluorescent probes and those providing valuable insight into optimized probe design have rarely been reported. Three BODIPY based fluorescent probes were made by conjugation of para-, ortho-, and meta-nitrobenzene to the BODIPY core via a thiolether bond, respectively. Our study revealed that the linkage and nitro substituent position significantly influence the capability of nitroreductase detection.
- Chen, Ji-An,Gao, Jie,Gu, Xianfeng,Li, Mimi,Tan, Jiahui,Yin, Xiaofan,Zhao, Zhen
-
supporting information
p. 4744 - 4747
(2020/07/13)
-
- Rh-Catalyzed Base-Free Decarbonylative Borylation of Twisted Amides
-
We report the rhodium-catalyzed base-free decarbonylative borylation of twisted amides. The synthesis of versatile arylboronate esters from aryl twisted amides is achieved via decarbonylative rhodium(I) catalysis and highly selective N-C(O) insertion. The method is notable for a very practical, additive-free Rh(I) catalyst system. The method shows broad functional group tolerance and excellent substrate scope, including site-selective decarbonylative borylation/Heck cross-coupling via divergent N-C/C-Br cleavage and late-stage pharmaceutical borylation.
- Bie, Fusheng,Liu, Xuejing,Shi, Yijun,Cao, Han,Han, Ying,Szostak, Michal,Liu, Chengwei,Liu, Xuejing,Szostak, Michal,Liu, Chengwei
-
p. 15676 - 15685
(2020/11/13)
-
- Homoleptic Bis(trimethylsilyl)amides of Yttrium Complexes Catalyzed Hydroboration Reduction of Amides to Amines
-
Homoleptic lanthanide complex Y[N(TMS)2]3 is an efficient homogeneous catalyst for the hydroboration reduction of secondary amides and tertiary amides to corresponding amines. A series of amides containing different functional groups such as cyano, nitro, and vinyl groups were found to be well-tolerated. This transformation has also been nicely applied to the synthesis of indoles and piribedil. Detailed isotopic labeling experiments, control experiments, and kinetic studies provided cumulative evidence to elucidate the reaction mechanism.
- Ye, Pengqing,Shao, Yinlin,Ye, Xuanzeng,Zhang, Fangjun,Li, Renhao,Sun, Jiani,Xu, Beihang,Chen, Jiuxi
-
supporting information
p. 1306 - 1310
(2020/02/22)
-
- Structure–activity relationships (SARs) of α- ketothioamides as inhibitors of phosphoglycerate dehydrogenase (PHGDH)
-
For many years now, targeting deregulation within cancer cells’ metabolism has appeared as a promising strategy for the development of more specific and efficient cancer treatments. Recently, numerous reports highlighted the crucial role of the serine synthetic pathway, and particularly of the phosphoglycerate dehydrogenase (PHGDH), the first enzyme of the pathway, to sustain cancer progression. Yet, because of very weak potencies usually in cell-based settings, the inhibitors reported so far failed to lay ground on the potential of this approach. In this paper, we report a structure–activity relationship study of a series of α-ketothioamides that we have recently identified. Interestingly, this study led to a deeper understanding of the structure–activity relationship (SAR) in this series and to the identification of new PHGDH inhibitors. The activity of the more potent compounds was confirmed by cellular thermal shift assays and in cell-based experiments. We hope that this research will eventually provide a new entry point, based on this promising chemical scaffold, for the development of therapeutic agents targeting PHGDH.
- Spillier, Quentin,Ravez, Séverine,Unterlass, Judith,Corbet, Cyril,Degavre, Charline,Feron, Olivier,Frédérick, Rapha?l
-
-
- Simple Synthesis of Amides via Their Acid Chlorides in Aqueous TPGS-750-M
-
The technology of surfactant chemistry is employed for amide bond construction via the reaction of acyl chlorides with amines in 2 wt % TPGS-750-M aqueous solution. Specifically, this highly efficient method enables a chromatography-free scalable process and recycling of the TPGS-750-M solution.
- Shi, Min,Ye, Ning,Chen, Wei,Wang, Hui,Cheung, Chiming,Parmentier, Michael,Gallou, Fabrice,Wu, Bin
-
supporting information
p. 1543 - 1548
(2020/11/23)
-
- Supramolecular Pd(II) complex of DPPF and dithiolate: An efficient catalyst for amino and phenoxycarbonylation using Co2(CO)8 as sustainable C1 source
-
Highly active, efficient and robust “dppf ligated tetranuclear palladium dithiolate complex” was synthesized and applied as a catalyst for chemical fixation of carbon monoxide for the synthesis value added chemicals such as tertiary amide and aromatic esters. The synthesized catalyst was characterized using different analytical techniques such as elemental analysis, 1H and 31P NMR spectroscopy. The use of Co2(CO)8 as a cheap, less toxic and low melting solid surrogate are additional advantages over the current protocol. The catalyst showed superior activity towards the Amino (10?3 mol % catalyst) and Phenoxycarbonylation (10-2 mol % catalyst) and high TON (104 to 103) and TOF (103 to 102 h-1). The Betol and Lintrin (active drug molecules) were synthesized under an optimized reaction condition. The scalability of the current protocol has been demonstrated up-to the gram level.
- Gaikwad, Vinayak V.,Mane, Pravin A.,Dey, Sandip,Patel, Divya,Bhanage, Bhalchandra M.
-
-
- N-Acyl-glutarimides: Effect of Glutarimide Ring on the Structures of Fully Perpendicular Twisted Amides and N-C Bond Cross-Coupling
-
N-Acyl-glutarimides have emerged as the most reactive precursors for N-C(O) bond cross-coupling reactions to date, wherein the reactivity is driven by ground-state destabilization of the amide bond. Herein, we report a full study on the effect of a glutarimide ring on the structures, electronic properties, and reactivity of fully perpendicular N-acyl-glutarimide amides. Most notably, this report demonstrates the generality of deploying N-acyl-glutarimides to achieve full twist of the acyclic amide bond, and results in the discovery of N-acyl-glutarimide amide with an almost perfect twist value, τ = 89.1°. X-ray structures of five new N-acyl-glutarimides are reported. Reactivity studies in the Suzuki-Miyaura cross-coupling and transamidation reactions provide insight into the reactivity of N-acyl-glutarimides in metal-catalyzed and transition-metal-free reactions. The effect of distortion, structures, and rotational barriers around the N-C(O) axis is discussed. The ability to achieve full distortion of the amide bond significantly expands the range of reagents available for N-C(O) cross-coupling reactions.
- Bisz, Elwira,Chen, Hao,Dziuk, B?a?ej,Lalancette, Roger,Liu, Chengwei,Rahman, Md. Mahbubur,Szostak, Michal,Szostak, Roman,Wang, Qi
-
p. 5475 - 5485
(2020/05/19)
-
- Synthesis method of amide compound
-
The invention discloses a synthesis method of an amide compound. The synthesis method comprises the following step: carrying out a photocatalytic reaction on benzyl alcohol with a structure as shown in a formula (I) and an amine compound with a structure as shown in a formula (II) in the presence of photocatalyst-loaded metal P-C3N4 by using an organic solvent as a medium to obtain the amide compound with a structure as shown in a formula (III). The synthesis method does not need a heat source for heat supply, avoids high-temperature reaction, is simple to operate, short in reaction time and simple in aftertreatment, and can easily realize industrial production.
- -
-
Paragraph 0039; 0045-0050
(2020/09/09)
-
- Well-defined N-heterocyclic carbene/ruthenium complexes for the alcohol amidation with amines: The dual role of cesium carbonate and improved activities applying an added ligand
-
Dehydrogenative amide bond formation from alcohols and amines has been regarded as an atom-economic and sustainable process. Among various catalytic systems, N-heterocyclic carbene (NHC)-based Ru catalytic systems have attracted growing interest due to the outstanding properties of NHCs as ligands. Herein, an NHC/Ru complex (1) was prepared and its structure was further confirmed with X-ray crystallography. In the presence of Cs2CO3, two NHC/Ru-based catalytic systems were disclosed to be active for this amide synthesis. System A, which did not contain any added ligand, required a catalyst loading of 1.00 mol%. Interestingly, improved catalytic performance was realized by the addition of an NHC precursor (L). Optimization of the amounts of L and other conditions gave rise to system B, a much more potent system with the Ru loading as low as 0.25 mol%. Moreover, an NHC-Ru-carbonate complex 6 was identified from the refluxing toluene of 1 and Cs2CO3, and further investigations revealed that 6 was an important intermediate for this catalytic reaction. Based on the above results, we claimed that the role of Cs2CO3 was to facilitate the formation of key intermediate 6. On the other hand, it provided the optimized basicity for the selective amide formation.
- Wang, Wan-Qiang,Yuan, Ye,Miao, Yang,Yu, Bao-Yi,Wang, Hua-Jing,Wang, Zhi-Qin,Sang, Wei,Chen, Cheng,Verpoort, Francis
-
-
- 3,6-Di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) catalysed metal-free amide bond formation from thioacids and amines at room temperature
-
A 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) catalysed efficient, mild and metal-free method has been developed for direct amide bond synthesis from simple thioacids and amines as starting materials. This methodology is useful for aromatic, aliphatic, and heteroaromatic thioacids as well as primary, secondary, heterocyclic, and even functionalized amines. A wide substrates scope, operationally mild conditions, and acylation of amines without affecting other functional groups such as alcohols, esters, carbodithioates, among others make this strategy very attractive and practical.
- Samanta, Suvendu,Ray, Shounak,Bhaduri, Samanka Narayan,Samanta, Partha Kumar,Biswas, Papu
-
supporting information
(2020/08/10)
-
- Graphene oxide: A convenient metal-free carbocatalyst for facilitating amidation of esters with amines
-
Herein, we report a graphene oxide (GO) catalyzed condensation of non-activated esters and amines, that can enable diverse amides to be synthesized from abundant ethyl esters forming only volatile alcohol as a by-product. GO accelerates ester to amide conversion in the absence of any additives, unlike other catalysts. A wide range of ester and amine substrates are screened to yield the respective amides in good to excellent yields. The improved catalytic activity can be ascribed to the oxygenated functionalities present on the graphene oxide surface which forms H-bonding with the reactants accelerating the reaction. Improved yields and a wide range of functional group tolerance are some of the important features of the developed protocol.
- Patel, Khushbu P.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
-
p. 2661 - 2668
(2020/02/20)
-
- 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
-
supporting information
(2020/11/13)
-
- Copper-catalyzed aerobic oxidative C-C bond cleavage of simple ketones for the synthesis of amides
-
A Cu-catalyzed oxidative amidation of simple ketones with amines via carbon-carbon (C-C) bond cleavage has been developed. A number of aryl and alkyl ketones could be easily converted to amides using cheap copper salt as the catalyst and O2 as the oxidant with a wide range of amines, including primary and secondary amines. This method shows a notable advantage of the broad scope for the substrate, thus providing a practical approach to amides. A plausible mechanism is proposed based on the preliminary experiments.
- Li, Ke,Liu, Wei,Liu, Yu-Feng,Yang, Guo-Ping,Zeng, Kai
-
p. 6958 - 6964
(2020/10/02)
-
- Palladium-Catalyzed Desulfurative Amide Formation from Thioureas and Arylboronic Acids
-
The development of the reactivity on carbene complexes would lead to the creation of novel synthetic strategies. We discovered herein the Pd-catalyzed desulfurative amide formation involved Suzuki-Miyaura coupling reaction, notably the Pd complex was generated in situ from thioureas, Ag salt and Pd catalyst. Silver salt was essential for the construction of this type of carbenes from available and stable thioureas and well participated in the catalytic cycle. We report a method for the synthesis of arylamides from arylboronic acids, which greatly enriched the application of thiourea chemistry and expanded the application of the Suzuki-Miyaura coupling.
- Su, Jianke,Li, Wendong,Li, Xin,Xu, Jian,Song, Qiuling
-
p. 5664 - 5668
(2020/10/02)
-
- Ultrafast amidation of esters using lithium amides under aerobic ambient temperature conditions in sustainable solvents
-
Lithium amides constitute one of the most commonly used classes of reagents in synthetic chemistry. However, despite having many applications, their use is handicapped by the requirement of low temperatures, in order to control their reactivity, as well as the need for dry organic solvents and protective inert atmosphere protocols to prevent their fast decomposition. Advancing the development of air- and moisture-compatible polar organometallic chemistry, the chemoselective and ultrafast amidation of esters mediated by lithium amides is reported. Establishing a novel sustainable access to carboxamides, this has been accomplished via direct C-O bond cleavage of a range of esters using glycerol or 2-MeTHF as a solvent, in air. High yields and good selectivity are observed while operating at ambient temperature, without the need for transition-metal mediation, and the protocol extends to transamidation processes. Pre-coordination of the organic substrate to the reactive lithium amide as a key step in the amidation processes has been assessed, enabling the structural elucidation of the coordination adduct [{Li(NPh2)(OCPh(NMe2))}2] (8) when toluene is employed as a solvent. No evidence for formation of a complex of this type has been found when using donor THF as a solvent. Structural and spectroscopic insights into the constitution of selected lithium amides in 2-MeTHF are provided that support the involvement of small kinetically activated aggregates that can react rapidly with the organic substrates, favouring the C-O bond cleavage/C-N bond formation processes over competing hydrolysis/degradation of the lithium amides by moisture or air.
- Bole, Leonie J.,Fairley, Michael,García-Alvarez, Joaquín,Hevia, Eva,Kennedy, Alan R.,Main, Laura,Mulks, Florian F.,O'Hara, Charles T.
-
p. 6500 - 6509
(2020/07/15)
-
- Amine-Mediated Bond Cleavage in Oxidized Lignin Models
-
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
-
p. 4660 - 4665
(2020/07/04)
-
- Triethyl Phosphite/Benzoyl Peroxide Mediated Reductive Dealkylation of O-Benzoylhydroxylamines: A Cascade Synthesis of Secondary Amides
-
A new triethyl phosphite/benzoyl peroxide (BPO) mediated system has been developed for the synthesis of secondary amides with good to excellent yields in a single step. This unprecedented cascade process involves sequential reduction of N–O bond and benzoylation followed by dealkylation of N–C bond of O-benzoylhydroxylamines (O-BHA). The methodology is versatile as it tolerates a variety of aromatic and aliphatic O-BHA as substrates to access secondary amides.
- Aegurla, Balakrishna,Mandle, Ram D.,Shinde, Prasad G.,Parit, Ratan S.,Kamble, Sanjay P.,Sudalai, Arumugam,Senthilkumar, Beeran
-
supporting information
p. 4235 - 4238
(2020/07/04)
-
- Double carbonylation of iodoarenes in the presence of a pyridinium SILP-Pd catalyst
-
The efficiency of a palladium catalyst, immobilised on a supported ionic liquid phase (SILP) with adsorbed 1-butyl-4-methylpyridinium chloride, was investigated in aminocarbonylation reactions. Double carbonylation was found to be the main reaction using different iodoarenes and aliphatic amines as substrates. Application of aniline derivatives as nucleophiles led to the exclusive formation of substituted benzamides. The stabilisation effect of the adsorbed pyridinium ionic liquid was compared to that of imidazolium and phosphonium derivatives. It was proved that the pyridinium SILP-palladium catalyst could be reused in at least 10 cycles. Recyclability was tested in five successive runs for all of the substrates.
- Nagy, Enik?,Nagy, Petra,Papp, Máté,Skoda-F?ldes, Rita,Urbán, Béla
-
-
- IrIII-Catalyzed direct syntheses of amides and esters using nitriles as acid equivalents: A photochemical pathway
-
An unprecedented IrIII[df(CF3)ppy]2(dtbbpy)PF6-catalyzed simple photochemical process for direct addition of amines and alcohols to the relatively less reactive nitrile triple bond is described herein. Various amides and esters are synthesized as the reaction products, with nitriles being the acid equivalents. A mini-library of different types of amides and esters is made using this mild and efficient process, which uses only 1 mol% of photocatalyst under visible light irradiation (λ = 445 nm). The reaction strategy is also efficient for gram-scale synthesis.
- Talukdar, Ranadeep
-
supporting information
p. 5303 - 5308
(2020/04/17)
-