- Chemoselective formal β-functionalization of substituted aliphatic amides enabled by a facile stereoselective oxidation event
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Aliphatic C-H functionalization is a topic of current intense interest in organic synthesis. Herein, we report that a facile and stereoselective dehydrogenation event enables the functionalization of aliphatic amides at different positions in a one-pot fa
- Bauer, Adriano,Maulide, Nuno
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- The preparation and reductive elimination behavior of trans-Pd(COPh)(CONMe2)(PMe3)2: a model intermediate in the catalytic double carbonylation of aryl halides with amines to give α-keto amides
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The cationic benzoylcarbonylpalladium(II) complex, trans-+BF41 (1), reacts with Me2NH under CO to give trans-Pd(COPh)(CONMe2)(PMe3)2 (3).Complex 3 is stable in neat solvent, whereas rapid decomposition of 3 to give PhCOCONMe2 takes place in the presence of Me2NH2BF4 and Me2NH under CO.
- Ozawa, Fumiyuki,Huang, Li,Yamamoto, Akio
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- Pd-Catalyst Containing a Hemilabile P,C-Hybrid Ligand in Amino Dicarbonylation of Aryl Halides for Synthesis of α-Ketoamides
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The amino dicarbonylation of aryl halides affording α-ketoamides with Pd catalysts is highly dependent on the stereoelectronic properties of the involved ligands. Ionic diphosphine ligand L4 can serve as precursor of a hemilabile P,C (phosphine, carbene)-hybrid ligand to form a stable Pd(II)-complex, Pd-L4. In contrast, analogues L1-L3 with a similar 1-(thiophen-3-yl)-benzimidazolyl skeleton behave as typical (mono/di)phosphines. The catalytic system resulting from the complexation of PdCl2(MeCN)2 and L4 exhibits good catalytic performance in terms of aryl iodides conversion (81-95%) and α-ketoamide selectivity (80-91%), as well as the available recyclability in the RTIL of [Bpy]BF4. The in situ FT-IR analysis reveals that the PdCl2(MeCN)2-L4 catalytic system favors the amino dicarbonylation toward α-ketoamides according to the proposed mechanism of cycle I, which involves two independent CO-insertion steps.
- Yang, Shu-Qing,Yao, Yin-Qing,Chen, Xiao-Chao,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 1032 - 1041
(2021/05/07)
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- Cu-Catalyzed aerobic oxidative cleavage of C(sp3)–C(sp3) bond: Synthesis of α-ketoamides
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A novel synthesis of α-ketoamides from Cu-catalyzed aerobic oxidative C(sp3)–C(sp3) bond cleavage of hydrocinnamaldehydes has been developed. Readily available and environmentally benign oxygen is used as the oxidant. This reaction avoids the use of noble metal catalysts or specialized oxidants, and chemoselectively yields α-ketoamide. Moreover, based on various control experiments, a reasonable mechanism is proposed.
- Fang, Zheng,Guo, Kai,Liu, Chengkou,Yang, Man,Zhang, Jingming
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supporting information
(2020/11/02)
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- Copper-Catalyzed Oxidative Synthesis of α-Ketoamides from Aryl Methyl Ketones and N -Bromobutanimide Using N, N -Dimethylformamide as Dimethylamine Source
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A novel and practical Cu(OAc) 2 -catalyzed oxidative synthesis of α-ketoamides from aryl methyl ketones and N -bromobutanimide (NBS) using N, N -dimethylformamide (DMF) as dimethylamine (HNMe 2) source and solvent has been developed under mild conditions. DMF was used as a HNMe 2 source and can be easily converted into HNMe 2 by acid hydrolysis. The mechanistic studies indicate that Cu(OAc) 2 plays a dual role in providing both catalyst and oxidant.
- Li, Xiaoyan,Wei, Ying,Yan, Yongxia
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p. 393 - 397
(2020/02/27)
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- Copper-Mediated Synthesis of Aryl α-Keto Amides from Epoxide Derivatives
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A novel Cu II -mediated synthesis of aryl α-keto amides from epoxide derivatives is reported. This transformation was conducted by using O 2 as a green oxidant that meets the requirements of sustainable chemistry.
- Cui, Yunjian,Dong, Yi,Liu, Fenghua,Xu, Heng
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supporting information
p. 1011 - 1014
(2020/06/10)
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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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- Double carbonylation of iodoarenes in the presence of a pyridinium SILP-Pd catalyst
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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
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- Development of palladium catalysts immobilized on supported phosphonium ionic liquid phases
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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
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p. 302 - 306
(2018/12/04)
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- Synthesis of Tridentate Chiral Spiro Aminophosphine?Oxazoline Ligands and Application to Asymmetric Hydrogenation of α-Keto Amides
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A new type of tridentate chiral spiro aminophosphine?oxazoline ligands (SpiroOAP) have been synthesized through four steps. The SpiroOAP ligands are highly efficient for the asymmetric hydrogenation of α-keto amides, providing a variety of synthetically useful α-hydroxy amides with excellent enantioselectivity (up to 98% ee) and turnover numbers (up to 10,000). (Figure presented.).
- Zhang, Feng-Hua,Wang, Chen,Xie, Jian-Hua,Zhou, Qi-Lin
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supporting information
p. 2832 - 2835
(2019/04/13)
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- Metal-Free C=C Double Bond Cleavage on Enaminones for the Synthesis of α-Ketoamides by Free-Radical Aerobic Oxygenation
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The tandem oxidation of the enaminone C=C double bond as well as subsequent C-N bond formation are realized under metal-free conditions by thermo-induced free radical transformation. In the presence of benzoyl peroxide (BPO) and N-iodosuccinimide (NIS), a
- Yang, Yiming,Zhong, Guofeng,Fan, Junfen,Liu, Yunyun
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supporting information
p. 4422 - 4425
(2019/06/24)
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- Stabilized Cu2O nanoparticles on rGO highly catalyzed direct oxidative coupling synthesis of Α-ketoamides with molecular oxygen
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In this study, a green, efficient, recyclable Cu2O nanoparticles on reduced graphene oxide (Cu2O-NPs@rGO) carbon-based composite catalyst was synthesized by facile one-pot hydrothermal method. And Cu2O-NPs@rGO catalyst was
- Lu, Weiyang,Sun, Wei,Tan, Xiaofeng,Wang, Bin,Yang, Hua,Gao, Lingfeng,Zheng, Gengxiu
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- Aerobic oxidative amidation of alkynes using titanium oxide encapsulated cuprous iodide nanoparticles (CuI@TiO2)
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A catalyst consisting of titanium oxide encapsulated cuprous iodide nanoparticles was prepared via a sol-gel method using inexpensive raw materials and was harnessed successfully in the oxidative amidation of alkynes via an environmentally benign and sustainable protocol. The mechanism of action of this transformation was thoroughly discussed. The robustness of the catalyst was elucidated by the synthesis of diverse analogues of α-ketoarylamide from a variety of electron rich and poor substrates via a simple procedure in moderate to high yields, with no generation of toxic by-products, in good recyclability up to five cycles, under solvent free and aerobic conditions. The chemical nature, morphology and loading of the CuI@TiO2 nanocatalyst were investigated by TEM, SEM, XPS, EDX, powder XRD, BET, TGA and ICP-MS.
- Dutta, Pratip Kumar,Dhar, Basabbijayi,Sen, Subhabrata
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p. 12062 - 12071
(2018/07/24)
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- Highly Site-Selective Metal-Free C-H Acyloxylation of Stable Enamines
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A highly site-selective acyloxylation of stable enamines with PhI(OAc)2 under metal-free conditions to afford (E)-vinyl acetate derivatives in good to excellent yields is described. Depending on the judicious choice of the solvent system, either the α- or β-site-selective product could be obtained with high selectivity. For the α-site-selective product, the rearranged amide compound is obtained as the major product. This reaction proceeds under mild reaction conditions (room temperature, metal-free, and open-flask) and features a broad substrate scope.
- Wang, Fei,Sun, Wangbing,Wang, Yixin,Jiang, Yaojia,Loh, Teck-Peng
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supporting information
p. 1256 - 1260
(2018/02/23)
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- UV Assisted High-Efficient Synthesis of α-Ketoamides using Air Promoted by A Non-Metal Catalyst in Aqueous Solution
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Presented here is the first example of UV (λ=210 nm) promoted procedure proceeding in aqueous media at room temperature using ambient air as the oxidant for efficient synthesis of an array of α-ketoamides of all types using a non-metal catalyst N-iodosuccinimide with a loading of 20 mol%. With UV, oxygen in the air was efficiently utilized as the green oxidant, some control experiments were carried out and a plausible mechanism was proposed, disclosing that in aqueous solution, the oxidation process was actually triggered by dioxygen radical anion (O2.?), while not molecular oxygen. A variety of secondary amines and primary amines as well as ammonia were employed as the amine moieties, and the desired product primary-, secondary-, and tertiary α-ketoamides were afforded in good to excellent yields of up to 96 %.
- Li, Jianhui,He, Shaopo,Zhang, Kuan,Quan, Ziyi,Shan, Qiheng,Sun, Zhongliang,Wang, Bo
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p. 4868 - 4873
(2018/10/15)
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- Copper(II)-mediated formation of oxazole-4-carbonitrile from acetophenone and coordinated cyanide anion: Via a radical coupling
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A protocol for the direct synthesis of 5-aryloxazole-4-carbonitrile from acetophenone was first described with potassium ferricyanide as a cheap and low toxicity cyanide reagent, in which, multiple bond formation was implemented via an oxygen mediated radical mechanism. Potassium ferricyanide played a dual role as a CN source and also as a coupling partner for the cyclization of oxazole.
- Xu, Congjun,Qin, Mingze,Yi, Jun,Wang, Yanjing,Chen, Yanfeng,Zhang, Bingfu,Zhao, Yanfang,Gong, Ping
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p. 24643 - 24646
(2017/07/11)
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- nBu4NI-Mediated oxidation of methyl ketones to α-ketoamides: using ammonium, primary and secondary amine-salt as an amine moiety
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Presented here is the first example of synthesizing an array of primary-, secondary-, and tertiary-α-ketoamides with a non-metal catalyst nBu4NI from methyl ketones and inexpensive readily available amine/ammonium salts; the reactions proceeded smoothly under mild conditions, TBHP was used as an oxidant and the corresponding α-ketoamides were afforded in moderate to excellent yields.
- Wang, Dan,Zhang, Kuan,Jia, Luhan,Zhang, Danting,Zhang, Yue,Cheng, Yujia,Lin, Chang,Wang, Bo
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p. 3427 - 3434
(2017/04/24)
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- Aminocarbonylation (hydrazinocarbonylation) of iodoalkenes and iodoarenes
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Iodoalkenes such as 1-iodocyclohexene, 4-tert-butyl-1-iodocyclohexene, α-iodostyrene and 17-iodoandrost-16-ene were aminocarbonylated in palladium-catalysed reaction using 1,1-disubstituted (cyclic) hydrazines (3-amino-3-azabicyclo[3.3.0]octane and (S)-1-amino-2-methoxymethylpyrrolidine (SAMP)/(R)-1-amino-2-methoxymethyl-pyrrolidine (RAMP)) as N-nucleophiles. The corresponding hydrazides were formed in moderate to high yields. The hydrazinocarbonylation of iodobenzene using the above 1,1-disubstituted hydrazines resulted in a rather complex reaction mixture due to two major types of side-reactions: i) the deamination of the 3-amino-3-azabicyclo[3.3.0]octane, and ii) the double carbon monoxide insertion. In this way, in addition to the expected benzoylhydrazide derivative, phenylglyoxylhydrazide (double CO insertion product) and benzamide (‘deamination’ product) were also formed. By the appropriate modification of the reaction conditions, good selectivities towards the target compounds were achieved even in these cases. The formation of the products/side-products were rationalized on the basis of a simplified catalytic cycle.
- Gergely, Máté,Kollár, László
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p. 838 - 844
(2017/02/05)
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- A Method to Access Symmetrical Tetrasubstituted Pyridines via Iodine and Ammonium Persulfate Mediated [2+2+1+1]-Cycloaddition Reaction
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A novel metal-free [2+2+1+1]-cycloaddition method for rapid and productive preparation of symmetrical 2,3,5,6-tetrasubstituted pyridines has been developed from α-substituted arones and N,N-dimethyl formamide (DMF) using iodine (I2) and ammonium persulfate ((NH4)2S2O8) as mediators. In this process, both DMF and (NH4)2S2O8 play a dual role for the formation of pyridines. DMF acts as the reaction medium and the C4 source (the methyl group of DMF), while (NH4)2S2O8 serves as the oxidant and nitrogen resource. Notably, this transformation exhibited a broad substrate scope towards a wide variety of different arones to give the corresponding tetrasubstituted pyridines in moderate to excellent yields. (Figure presented.).
- Liu, Weibing,Tan, Hua,Chen, Cui,Pan, Yupeng
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supporting information
p. 1594 - 1598
(2017/05/05)
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- Transition metal-free synthesis of α-ketoamides from arylmethyl ketones and alkylphosphoramides
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A transition metal-free protocol has been developed for the synthesis of α-ketoamides from aryl methyl ketones and alkylphosphoramides in the presence of oxidant, aqueous tert-butyl hydroperoxide (TBHP). A series of aryl methyl ketones having both electron-donating as well as electron-withdrawing groups were successfully employed for the synthesis of their corresponding α-ketoamides using hexamethylphosphoramide and other alkylphosphoramides.
- Behera, Ahalya,Ali, Wajid,Tripathy, Manisha,Sahoo, Diptimayee,Patel, Bhisma K.
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p. 91308 - 91313
(2016/10/09)
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- Copper-catalyzed, hypervalent iodine mediated C=C bond activation of enaminones for the synthesis of α-keto amides
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An unprecedented C=C bond cleavage of enaminones has been realized by means of copper catalysis in the presence of hypervalent iodine (PhI(OAc)2). The cascade transformation based on this bond cleavage leads to the synthesis of various α-keto amides. Isotope labeling experiments suggest that water has acted as a source of oxygen atoms during the generation of the new carbonyl group.
- Wan, Jie-Ping,Lin, Yunfang,Cao, Xiaoji,Liu, Yunyun,Wei, Li
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supporting information
p. 1270 - 1273
(2016/01/15)
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- Metal-Free Amidation of Acids with Formamides and T3P
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A new, simple and metal-free method for the direct formation of dialkylamides from carboxylic acids employing N,N-dialkylformamides as amine source is described. The one-pot reaction is promoted by propylphosphonic anhydride (T3P) in the presence of 0.5 equivalents of HCl.
- Bannwart, Linda,Abele, Stefan,Tortoioli, Simone
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p. 2069 - 2078
(2016/07/06)
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- TBAI-catalyzed synthesis of α-ketoamides via sp3 C-H radical/radical cross-coupling and domino aerobic oxidation
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A TBAI-catalyzed one-pot synthesis of α-ketoamides via sp3 C-H radical/radical cross-coupling and domino aerobic oxidation was developed. This synthesis is suitable for abroad range of substrates. The control experiments suggested a possible oxidative coupling mechanism.
- Fan, Weizheng,Shi, Dongyang,Feng, Bainian
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supporting information
p. 4638 - 4641
(2015/07/02)
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- Synthesis of α -Ketoamides by Copper-Catalyzed Reactions of Phenylacetic Acids with N,N -Dialkylformamides
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A new synthetic approach for α-ketoamides was achieved by copper-catalyzed coupling reactions between N,N-dialkylformamides and phenylacetic acids. A variety of substrates were well tolerated to give yields of 46-87% (17 examples). A 13C-labeli
- Zhang, Lanping,Pu, Junnan,Ren, Jiayu,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
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p. 1848 - 1856
(2015/08/03)
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- Synthesis of α-ketoamides from Aryl methyl ketones and N, N -dimethylformamide via copper-catalyzed aerobic oxidative coupling
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A copper-catalyzed aerobic oxidative coupling of aryl methyl ketones with N,N-dimethylformamide was developed, which afforded α-ketoamides by a sequence of dioxygen activation, C-H bond functionalization, and amide formation with N,N-dimethylformamide as
- Zhou, Mingxin,Song, Qiuling
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p. 1853 - 1858
(2014/07/22)
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- The syntheses of α-ketoamides vianBu4NI- catalyzed multiple sp3C-H bond oxidation of ethylarenes and sequential coupling with dialkylformamides
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The nBu4NI-catalyzed sequential C-O and C-N bond formation via multiple sp3C-H bond activation of ethylarenes, using N,N-dialkylformamide as the amino source, provided α-ketoamides with moderate yields. This journal is
- Du, Bingnan,Jin, Bo,Sun, Peipei
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supporting information
p. 4586 - 4589
(2014/06/24)
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- Phosphine-free double carbonylation of iodobenzene in the presence of reusable supported palladium catalysts
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Various silica supported palladium catalysts were prepared and tested in the double carbonylation of iodobenzene in the presence of secondary amines. The catalysts were proved to produce α-ketoamide products with excellent selectivity in most cases. At the same time, bulky amines hindered double carbonylation and led to the formation of amides as the main products. Under optimal conditions, the catalysts could be recycled at least six times. An increase in the reaction time led to a decrease in the amount of leached palladium.
- Papp, Máté,Skoda-F?ldes, Rita
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p. 193 - 199
(2013/08/23)
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- Copper-catalyzed oxidative condensation of α-oxocarboxylic acids with formamides: Synthesis of α-ketoamides
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A copper-catalyzed coupling of α-oxocarboxylic acids with formamides is reported. This simple method provides a practical approach toward the synthesis of α-ketoamides with a variety of functional groups. Mechanistic studies have shown that the reaction proceeded via a radical process and 13C-labeled experiments proved that the amide carbon in the products comes from the corresponding carboxylic acid, not from the DMF. is
- Wang, Hua,Guo, Li-Na,Duan, Xin-Hua
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p. 4573 - 4576
(2013/07/26)
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- Silver-catalyzed amidation of benzoylformic acids with tertiary amines via selective carbon-nitrogen bond cleavage
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A novel approach towards the synthesis of α-ketoamides using tertiary amines as nitrogen group sources via C-N bond cleavage has been developed. In the presence of Ag2CO3 and K2S 2O8, α-keto acids reacted with tertiary amines to afford the corresponding α-ketoamides in good yields. The Royal Society of Chemistry 2013.
- Zhang, Xiaobin,Yang, Wenchao,Wang, Lei
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p. 3649 - 3654
(2013/06/26)
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- Cu(ii)-catalyzed decarboxylative acylation of acyl C-H of formamides with α-oxocarboxylic acids leading to α-ketoamides
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CuBr2-catalyzed decarboxylative acylation of the acyl C-H of N-monosubstituted and N,N-disubstituted formamides with α-oxocarboxylic acids leading to α-ketoamides was developed, which generated the corresponding products in good yields. The Royal Society of Chemistry 2013.
- Li, Dengke,Wang, Min,Liu, Jie,Zhao, Qiong,Wang, Lei
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supporting information
p. 3640 - 3642
(2013/05/21)
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- Direct use of formamides as amino group sources via C-N bond cleavage: A catalytic oxidative synthesis of α-ketoamides from acetophenones and formamides under metal-free conditions
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An efficient and direct use of formamides as amino group sources for the synthesis of α-ketoamides was developed under metal-free conditions. The reaction was based on the oxidative coupling of acetophenones with formamides and generated the desired products in good yields in the presence of t-BuOOH/I2/PhCO2H.
- Zhao, Qiong,Miao, Tao,Zhang, Xiaobin,Zhou, Wei,Wang, Lei
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p. 1867 - 1873
(2013/04/10)
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- Coupling of methyl ketones and primary or secondary amines leading to α-ketoamides
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A metal-free oxidative coupling of methyl ketones and primary or secondary amines to α-ketoamides has been developed. Four intermediates, α-iodoketone, α-aminoketone, iminium intermediate, and α-hydroxy amine have been identified through a series of control experiments. The atom-economic methodology can be scaled-up, tolerates a variety of functional groups, and is operationally simple.
- Wei, Wei,Shao, Ying,Hu, Huayou,Zhang, Feng,Zhang, Chao,Xu, Yuan,Wan, Xiaobing
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p. 7157 - 7165
(2012/11/07)
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- Copper-catalyzed aerobic oxidative synthesis of α-ketoamides from methyl ketones, amines and NIS at room temperature
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A simple, efficient and practical copper-catalyzed aerobic oxidative synthesis of α-ketoamides from aryl methyl ketones, aliphatic amines and N-iodosuccinimide (NIS) has been developed. The one-pot reaction may proceed smoothly at room temperature in the open air. The possible mechanism for the formation of α-ketoamides was proposed. Molecular oxygen in air functions as both an oxidant and an oxygen source.
- Zhang, Juan,Wei, Ying,Lin, Shaoxia,Liang, Fushun,Liu, Pengjun
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p. 9237 - 9242
(2013/01/15)
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- NBu4NI-catalyzed direct synthesis of α-ketoamides from aryl methyl ketones with dialkylformamides in water using TBHP as oxidant
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A novel and easy practical direct synthesis of α-ketoamides has been developed without metals in water. This procedure was catalyzed by nBu 4NI using TBHP as oxidant from simple substrates, aryl methyl ketones and dialkylformamides. The Royal Society of Chemistry 2012.
- Mai, Wen-Peng,Wang, Hui-Hui,Li, Zhi-Cheng,Yuan, Jin-Wei,Xiao, Yong-Mei,Yang, Liang-Ru,Mao, Pu,Qu, Ling-Bo
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supporting information
p. 10117 - 10119
(2012/10/30)
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- Elusive ethynyl azides: Trapping by 1,3-dipolar cycloaddition and decomposition to cyanocarbenes
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Although they decompose rapidly to produce cyanocarbenes, ethynyl azides were generated from (chloroethynyl)arenes and trapped for the first time by 1,3-dipolar cycloaddition at cyclooctyne.
- Banert, Klaus,Hagedorn, Manfred,Wutke, Jens,Ecorchard, Petra,Schaarschmidt, Dieter,Lang, Heinrich
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supporting information; experimental part
p. 4058 - 4060
(2010/09/06)
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- Aerial oxidation of 2,2-dibromo-1-aryl and heteroaryl ethanones: A facile synthesis of aryl and heteroaryl α-keto amides
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The aerial oxidation of various 2,2-dibromo-1-aryl and heteroaryl ethanones to α-keto amides in the presence of air or oxygen and secondary amines are described. The reaction provides α-keto amides in moderate to good yields. The versatility of the reacti
- Shanmugapriya,Shankar,Satyanarayana,Dahanukar, Vilas H.,Kumar, U. K. Syam,Vembu
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experimental part
p. 2945 - 2950
(2009/06/25)
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- Synthesis of α-ketoamides from a carbamoylsilane and acid chlorides
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Treatment of acid chlorides with a carbamoylsilane affords α-ketoamides. In some instances, in situ reaction of additional carbamoylsilane with these products yielded α-organyl-α- siloxymalonamides.
- Chen, Jianxin,Cunico, Robert F.
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p. 5509 - 5511
(2007/10/03)
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- Hypervalent iodine in synthesis 68: Palladium-catalysed double carbonylation of diaryliodonium salts to give α-keto-amides
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In the presence of a palladium catalyst and the cocatalyst Cul, several diaryliodonium salts have been converted into α-keto amides on treatment with secondary amines and carbon monoxide in good yield and selectivity under mild reaction conditions.
- Zhou, Tao,Chen, Zhen-Chu
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p. 116 - 117
(2007/10/03)
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- The Chemistry of 5-Oxodihydroisoxazoles. Part 23. Photochemical and Thermal Reactions of Isoxazol-5(2H)-ones Substituted at C-3 or C-4 with Nitrogen, Oxygen or Sulfur
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The photolysis of 2,3-dimethyl-4-phenoxy- and 4-thiophenoxyisoxazol-5(2H)-one in methanol has been re-examined, but no new products were isolated. Flash vacuum pyrolysis of the former gave a novel product, phenyl N-methylpropenimidate, from rearrangement of the intermediate carbene. Irradiation of the 3-hydroxy-2-phenyl-4-carboxylate gave two products which arise from the 3-hydroxy and 5-hydroxy tautomers. By contrast, the 3-hydroxy-4-acetyl isoxazolone reacted exclusively as one tautomer giving the expected loss of CO2 to form the carbene which was captured by methanol on photolysis, or underwent methyl migration and cyclisation to 3-methylazetidine-1,3-dione on pyrolysis. 3-Amino and 3-phenylamino substituted isoxazolones also gave photolysis and pyrolysis products characteristic of discrete tautomers.
- Khalafy, Jabbar,Prager, Rolf H.,Smith, Jason A.
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p. 518 - 536
(2007/10/03)
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- Formation by Mixing of Chiral Host-Achiral Guest Inclusion Complexes in which the Guest Molecules are Arranged in a Chiral Form. Production of Optically Active Photocyclisation Compounds by Irradiation of the Inclusion Complexes
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Mixing of powdered chiral hosts and achiral N,N-dialkylphenylglyoxylamide guest compounds gives inclusion complexes in which the latter molecules are arranged in a chiral form, although such complexes are not obtained by recrystallisation: the chirality of the guest compounds are frozen by photoreaction which gives optically active β-lactams and oxazolidinones.
- Toda, Fumio,Miyamoto, Hisakazu,Kanemoto, Kazuyuki
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p. 1719 - 1720
(2007/10/02)
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- α-Keto Amides and 1,2-Diketones from N,N'-Dimethoxy-N,N'-dimethylethanediamide. A Synthetic and Mechanistic Investigation
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N,N'-Dimethoxy-N,N'-dimethylethanediamide (1), a 1,2-dicarbonyl synthon prepared from oxalyl chloride, undergoes nucleophilic displacements with Grignard reagents to provide α-keto amides 2-12 in 28-90percent yields.The synthon also undergoes double nucleophilic displacements with organolithium reagents to furnish symmetrical 1,2-diketones 15-23 in 15-84percent yields.A mechanism accounting for all the products from the reaction of 1 with nucleophiles has been proposed.Several control experiments were carried out to support the proposed mechanism.
- Sibi, Mukund P.,Marvin, Mali,Sharma, Rajiv
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p. 5016 - 5023
(2007/10/03)
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- Reactions of benzoyl(carbonyl)transition metal complexes with LiNMe2: on the feasibility of a reaction route to α-keto amide through an acyl(carbamoyl)cobalt intermediate
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CO-coordinated benzoyltransition metal complexes, PhCOCo(CO)3L (L = PPh3, PCy3, and PMe3), PhCOMn(CO)5, and PhCORe(CO)5, have been prepared and their reactions with LiNMe2 examined.The reactions give α-keto amide (PhCOCONMe2) after treating the system with Br2 or organic haldes.
- Kawasaki, Nobuo,Masuzoe, Kenji,Ozawa, Fumiyuki,Yamamoto, Akio
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p. C37 - C40
(2007/10/02)
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- Reactions of α-Hydroxy Carbonyl Compounds with Azodicarboxylates and Triphenylphosphine: Synthesis of α-N-Hydroxy Amino Acid Derivatives
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Reaction of aliphatic α-hydroxy esters with azodicarboxylates and triphenylphosphine in the presence of either CbzNHOCH2Ph or trOCNHOCH2Ph provides a direct route to protected α-N-hydroxy amino acids.Similar reactions with aromatic α-hydroxy carbonyl compounds and derivatives result in predominate oxidation to the corresponding α-oxo carbonyl derivatives.
- Kolasa, Teodozyj,Miller, Marvin J.
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p. 4978 - 4984
(2007/10/02)
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- Cyano-O-silylhydroxylamines as Nitrone Blocking Groups
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Addition of trimethylsilyl cyanide to N-alkyl-C-phenylnitrones affords cyano-O-silylhydroxylamines; reaction of these species with silver fluoride regenerates the nitrone in quantitative yield thereby providing a useful nitrone blocking group.
- Padwa, Albert,Koehler, Konrad F.
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p. 789 - 790
(2007/10/02)
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- Palladium-Catalysed Double Carbonylation of Aryl Halides To Give α-Keto Amides. Mechanistic Studies
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Various aryl halides are catalytically converted into α-keto amides and amides on treatment with secondary amines and carbon monoxide.Palladium complexes containing tertiary phosphine ligands, particularly diphenylmethylphosphine and 1,4-bis(diphenylphosphino)butane, are most effective among other transition-metal complexes.Detailed examination of factors controlling the reaction rates and selectivity for α-keto amide formation revealed the following characteristics of the reactions. (a) Reactivity of phenyl halide decreases in the order PhI > PhBr >> PhCl. (b) Oxidative addition of phenyl bromide constitutes the rate-determining step in double carbonylation of phenyl bromide, whereas in the reaction of phenyl iodide the rate determinig step is associated with the reaction of a catalitically active palladium species with carbon monoxide. (c) Introduction of an electron-withdrawing substituent into the para position of phenyl halide enhances the reactivity but decreases the selectivity for α-keto amide. (d) Employment of amines of high basicity (pKb Et2NH > piperidine > hexamethyleneimine > Me2NH > pyrrolidine probably reflects the decrease in steric bulkiness of amines. (f) Although primary amines are in general not suitable for the double carbonylation, tert-butylamine can be used because of its inertness to the product α-keto amide.Reactivity of trans-PdPh(I)(PMePh2)2 and trans-Pd(COPh)I(PMePh2)2, supposed intermediates in the catalytic reaction of PhI, toward amines and CO was examined.The relative reactivity of six secondary amines with the benzoylpalladium complex increasing in the order Pr2NH Et2NH piperidine Me2NH hexamethyleneimine pyrrolidine was found to be inversely correlated with decreasing selectivity order for α-keto amide formation in the catalytic systems.On the basis of the experimental results, a mechanism consisting of two catalytic cycles to produce α-keto amides and amides has been proposed.
- Ozawa, Fumiyuki,Soyama, Hidehiko,Yanagihara, Hisayoshi,Aoyama, Issei,Takino, Hiroaki,et al.
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p. 3235 - 3245
(2007/10/02)
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- Ru-CATALYZED OXIDATION OF SUBSTITUTED ACETYLENES TO α-KETO ESTERS AND α-KETO AMIDES WITH IODOSYLBENZENE
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Oxidation of alkynyl ethers and -amines with iodosylbenzene in presence of Ru-catalysts affords α-keto esters and α-keto amides in 44-84percent yield.These conversions can also be effected with RuO4.
- Mueller, Paul,Godoy, Jose
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p. 3661 - 3664
(2007/10/02)
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