- Access to Branched Allylarenes via Rhodium(III)-Catalyzed C-H Allylation of (Hetero)arenes with 2-Methylidenetrimethylene Carbonate
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A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
- Zhang, Shang-Shi,Zheng, Yi-Chuan,Zhang, Zi-Wu,Chen, Shao-Yong,Xie, Hui,Shu, Bing,Song, Jia-Lin,Liu, Yan-Zhi,Zeng, Yao-Fu,Zhang, Luyong
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supporting information
p. 5719 - 5723
(2021/08/16)
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- Direct Oxygenation of C-H Bonds through Photoredox and Palladium Catalysis
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This report presents the oxygenation of C-H bonds via the merger of photocatalysis and Pd catalysis. Herein, we describe the utilization of a photocatalyst to oxidize an organopalladium(II) intermediate to high-valent PdIII or PdIV intermediates, which promotes the formation of C-O bonds. The demonstrated method works efficiently with various directing groups, such as oxime ether and benzothiazole. The applicability of this direct C-O bond formation method is shown by synthesizing several metal complexes of 2-(benzo[d]thiazol-2-yl)phenol that can be used in organic light-emitting diodes and pharmaceuticals.
- Paul, Amrita,Shah, Sk. Sheriff,Shee, Maniklal,Singh, Amit Kumar,Singh, N. D. Pradeep
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p. 3426 - 3439
(2020/03/23)
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- Synthesis and evaluation of aromatic methoxime derivatives against five postharvest phytopathogenic fungi of fruits. Main structure–activity relationships
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The antifungal activity of a library of twenty-four aromatic methoximes was examined against five representative postharvest phytopathogenic fungi. The panel included Penicillium digitatum, Penicillium italicum, Rhizopus stolonifer, Botrytis cinerea and Monilinia fructicola, all of which cause relevant economic losses worldwide as a result of affecting harvested fruits. The minimum inhibitory concentrations and minimum fungicidal concentrations of each compound were defined and the main structure–activity relationships were determined. Although other congeners were more potent, drug likeliness considerations pointed to the methoxime derived from 2,4-dihydroxypropiophenone as the compound with the most suitable profile. The morphology of the colonies of the fungal strains treated with the methoxime was examined microscopically and the compound was also tested in freshly harvested peaches and oranges, exhibiting promising control profiles in both fruits, similar to those of the commercial agents Imazalil and Carbendazim.
- Cortés, Iván,di Liberto, Melina G.,Kaufman, Teodoro S.,Derita, Marcos G.,Bracca, Andrea B.J.
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- Rhodium(III)-Catalyzed Oxidative Annulation of Ketoximes with Sulfonamide: A Direct Approach to Indazoles
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A rhodium(III)-catalyzed intermolecular C-H amination of ketoxime and iodobenzene diacetate-enabled N-N bond formation in the synthesis of indazoles has been developed. A variety of functional groups were well tolerated, providing the corresponding produc
- Wang, Ning,Liu, Lingling,Xu, Wentao,Zhang, Mengye,Huang, Zhibin,Shi, Daqing,Zhao, Yingsheng
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supporting information
(2019/01/21)
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- Rhodium(III)-Catalyzed Oxidative Annulation of Ketoximes with Sulfonamide: A Direct Approach to Indazoles
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A rhodium(III)-catalyzed intermolecular C-H amination of ketoxime and iodobenzene diacetate-enabled N-N bond formation in the synthesis of indazoles has been developed. A variety of functional groups were well tolerated, providing the corresponding products in moderate to good yields. Moreover, the nitro-substituted ketoximes are well compatible in this reaction, leading to the corresponding products in moderate to good yields.
- Wang, Ning,Liu, Lingling,Xu, Wentao,Zhang, Mengye,Huang, Zhibin,Shi, Daqing,Zhao, Yingsheng
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supporting information
p. 365 - 368
(2019/01/24)
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- Reusable Palladium Nanoparticles Catalyzed Oxime Ether Directed Mono Ortho-Hydroxylation under Phosphine Free Neutral Condition
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An efficient, reusable and stable binaphthyl stabilized Pd-nanoparticles (Pd-BNP) catalyzed the direct ortho-C?H hydroxylation of acetophenone oxime ethers under neutral and phosphine ligand-free condition has been developed. A readily available, economic, safe and greener oxidant oxone has been used in this direct ortho-hydroxylation. The scope of the reaction has been studied with various acetophenone oxime ethers including electron rich to electron deficient system and the reaction afforded only mono hydroxylated products in a highly regioselective manner. Several control experiment results confirmed that the oxone is the hydroxyl source. The Pd-BNP catalyst has been reused up to five times. The heterogeneous test confirmed that the reaction is catalyzed by the heterogeneous Pd-BNP catalyst. (Figure presented.).
- Saha, Rajib,Perveen, Naziya,Nihesh, Naorem,Sekar, Govindasamy
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supporting information
p. 510 - 519
(2018/12/11)
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- Catalyst-Controlled [3 + 2] and [4 + 2] Annulations of Oximes with Propargyl Alcohols: Divergent Access to Indenamines and Isoquinolines
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Rhodium(III)- and iridium(III)-catalyzed C-H activation of oximes and coupling with propargyl alcohols is discussed. Depending on the catalyst, the reaction pathway switched between [3 + 2] and [4 + 2] annulations, thus giving divergent access to indenami
- Gong, Wanchun,Zhou, Zhi,Shi, Jingjing,Wu, Bo,Huang, Biyun,Yi, Wei
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supporting information
p. 182 - 185
(2018/01/17)
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- Palladium-Catalyzed C(sp2)-H Acetoxylation via Electrochemical Oxidation
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Palladium-catalyzed arene C(sp2)-H acetoxylation has emerged as a powerful tool to construct a carbon-oxygen (C-O) bond. However, the requirement of stoichiometric chemical oxidants for this transformation possesses a significant disadvantage.
- Li, Yi-Qian,Yang, Qi-Liang,Fang, Ping,Mei, Tian-Sheng,Zhang, Dayong
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supporting information
p. 2905 - 2908
(2017/06/07)
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- Palladium-catalyzed C-H activation/C-C cross-coupling reactions: Via electrochemistry
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Palladium-catalyzed C-H activation/C-C cross-coupling reactions typically require stoichiometric chemical oxidants and exogenous ligands. However, there are significant disadvantages associated with the use of traditional stoichiometric oxidants. To overcome these issues, we have developed an electrochemical strategy to achieve methylation and acylation.
- Ma, Cong,Zhao, Chuan-Qi,Li, Yi-Qian,Zhang, Li-Pu,Xu, Xue-Tao,Zhang, Kun,Mei, Tian-Sheng
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supporting information
p. 12189 - 12192
(2017/11/16)
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- Cyclic Hydroxamic Acid Analogues of Bacterial Siderophores as Iron-Complexing Agents prepared through the Castagnoli–Cushman Reaction of Unprotected Oximes
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The first application of multicomponent chemistry (the Castagnoli–Cushman reaction) toward the convenient one-step preparation of cyclic hydroxamic acids is described. Cyclic hydroxamic acids are close analogues of bacterial siderophores (iron-binding com
- Bakulina, Olga,Bannykh, Anton,Dar'in, Dmitry,Krasavin, Mikhail
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supporting information
p. 17667 - 17673
(2017/12/26)
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- Palladium-catalyzed enolate arylation as a key C-C bond-forming reaction for the synthesis of isoquinolines
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The palladium-catalyzed coupling of an enolate with an ortho-functionalized aryl halide (an α-arylation) furnishes a protected 1,5-dicarbonyl moiety that can be cyclized to an isoquinoline with a source of ammonia. This fully regioselective synthetic route tolerates a wide range of substituents, including those that give rise to the traditionally difficult to access electron-deficient isoquinoline skeletons. These two synthetic operations can be combined to give a three-component, one-pot isoquinoline synthesis. Alternatively, cyclization of the intermediates with hydroxylamine hydrochloride engenders direct access to isoquinoline N-oxides; and cyclization with methylamine, gives isoquinolinium salts. Significant diversity is available in the substituents at the C4 position in four-component, one-pot couplings, by either trapping the in situ intermediate after α-arylation with carbon or heteroatom-based electrophiles, or by performing an α,α-heterodiarylation to install aryl groups at this position. The α-arylation of nitrile and ester enolates gives access to 3-amino and 3-hydroxyisoquinolines and the α-arylation of tert-butyl cyanoacetate followed by electrophile trapping, decarboxylation and cyclization, C4-functionalized 3-aminoisoquinolines. An oxime directing group can be used to direct a C-H functionalization/bromination, which allows monofunctionalized rather than difunctionalized aryl precursors to be brought through this synthetic route.
- Pilgrim, Ben S.,Gatland, Alice E.,Esteves, Carlos H. A.,McTernan, Charlie T.,Jones, Geraint R.,Tatton, Matthew R.,Procopiou, Panayiotis A.,Donohoe, Timothy J.
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p. 1065 - 1090
(2016/01/15)
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- Synthesis of 2-fluorocholine aryl carbonyl compounds
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The invention provides a method for synthesizing 2-fluoroarylcarbonyl compounds, which comprises the following steps: converting arylcarbonyl compounds into corresponding carbonyl oxime ether compounds, mildly implementing aryl hydrocarbon chain direct fluoridation of high-selectivity oximido substituent group ortho-position in the presence of a palladium catalyst, a fluoridation reagent and additives, and finally, rehydrolyzing oxime ethers under the action of acid to obtain the 2-fluoroarylcarbonyl compounds. The fluoridation method has the advantages of mild reaction conditions, high substrate adaptability, high fluoridation selectivity and the like, is simple to operate, and has higher application research value.
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Paragraph 0115
(2017/02/09)
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- NHPI and palladium cocatalyzed aerobic oxidative acylation of arenes through a radical process
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The NHPI and palladium cocatalyzed radical oxidative acylation of arenes with aldehydes and alcohols as acyl equivalents via selective C-H functionalization has been described. Molecular oxygen, the most environmentally friendly oxidant, was used as the terminal oxidant in this catalytic cycle.
- Liang, Yu-Feng,Wang, Xiaoyang,Tang, Conghui,Shen, Tao,Liu, Jianzhong,Jiao, Ning
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supporting information
p. 1416 - 1419
(2016/01/25)
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- Palladium-Catalyzed Decarboxylative Ortho-Ethoxycarbonylation of O-Methyl Ketoximes and 2-Arylpyridines with Potassium Oxalate Monoester
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A novel method for introducing an ester group via palladium-catalyzed ligand-directed C-H activation has been explored. The ortho-ethoxycarbonylation of O-methyl ketoximes proceeded smoothly with the nontoxic and easily handled reagent potassium oxalate monoester, affording the desired products in moderate to good yields. Furthermore, pyridine could also be employed as a directing group to obtain similar results in this transformation.
- Li, Zhong-Yuan,Wang, Guan-Wu
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supporting information
p. 4866 - 4869
(2015/10/12)
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- Rhodium-catalyzed directed C-H cyanation of arenes with N-cyano-N-phenyl-p-toluenesulfonamide
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A Rh-catalyzed directed C-H cyanation reaction was developed for the first time as a practical method for the synthesis of aromatic nitriles. N-Cyano-N-phenyl-p-toluenesulfonamide, a user-friendly cyanation reagent, was used in the transformation. Many different directing groups can be used in this C-H cyanation process, and the reaction tolerates a variety of synthetically important functional groups.
- Gong, Tian-Jun,Xiao, Bin,Cheng, Wan-Min,Su, Wei,Xu, Jun,Liu, Zhao-Jing,Liu, Lei,Fu, Yao
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supporting information
p. 10630 - 10633
(2013/08/23)
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- Synthesis of biaryl imino/keto carboxylic acids via aryl amide directed C-H activation reaction
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A novel Pd-catalysed C-H activation reaction for the synthesis of biaryl imino/keto carboxylic acids is developed. This reaction underwent aryl amide directed C-H activation ortho-acylation followed by ring closing and ring opening processes to give a range of biaryl imino/keto carboxylic acids. Our methodology features the utilization of a cheap and green oxidant (TBHP) as well as readily available aldehydes.
- Zhang, Nana,Yu, Qingzhen,Chen, Ruixue,Huang, Jianhui,Xia, Yeqing,Zhao, Kang
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p. 9464 - 9466
(2013/10/01)
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- Stereospecific Suzuki, Sonogashira, and Negishi coupling reactions of N-alkoxyimidoyl iodides and bromides
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A high-yielding stereospecific route to the synthesis of single geometric isomers of diaryl oxime ethers through Suzuki coupling of N-alkoxyimidoyl iodides is described. This reaction occurs with complete retention of the imidoyl halide geometry to give single E- or Z-isomers of diaryl oxime ethers. The Sonogashira coupling of N-alkoxyimidoyl iodides and bromides with a wide variety of terminal alkynes to afford single geometric isomers of aryl alkynyl oxime ethers has also been developed. Several of these reactions proceed through copper-free conditions. The Negishi coupling of N-alkoxyimidoyl halides is introduced. The E and Z configurations of nine Suzuki-coupling products and two Sonogashira-coupling products were confirmed by X-ray crystallography.
- Dolliver, Debra D.,Bhattarai, Bijay T.,Pandey, Arjun,Lanier, Megan L.,Bordelon, Amber S.,Adhikari, Sarju,Dinser, Jordan A.,Flowers, Patrick F.,Wills, Veronica S.,Schneider, Caroline L.,Shaughnessy, Kevin H.,Moore, Jane N.,Raders, Steven M.,Snowden, Timothy S.,McKim, Artie S.,Fronczek, Frank R.
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p. 3676 - 3687
(2013/06/04)
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- Direct sequential C-O and C-C formation via double sp2 C-H bond activations to construct 6H-benzo[c]chromen-6-ones
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A new method for the direct ortho acyloxylation of sp2 C-H bond with various carboxylic acids was developed. A novel strategy to synthesize 6H-benzo[c]chromen-6-one derivatives was designed via Pd-catalyzed double activations of adjacent spsup
- Sun, Chang-Liang,Liu, Jia,Wang, Yang,Zhou, Xiao,Li, Bi-Jie,Shi, Zhang-Jie
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supporting information; experimental part
p. 883 - 886
(2011/06/17)
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- Palladium-catalyzed cross coupling reaction of N-alkoxyimidoyl bromides and its application to one-pot synthesis of N-arylamines
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The synthetic utility of N-alkoxyimidoyl halides is demonstrated using the palladium-catalyzed cross-coupling reaction. The Sonogashira and Suzuki-Miyaura coupling reactions of N-alkoxyimidoyl bromides produced versatile ketoxime ethers in good to excelle
- Ueda, Masafumi,Sugita, Shoichi,Aoi, Naoki,Sato, Aoi,Ikeda, Yuki,Ito, Yuta,Miyoshi, Tetsuya,Naito, Takeaki,Miyata, Okiko
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scheme or table
p. 1206 - 1208
(2011/10/05)
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- SUBSTITUTED N-BICYCLICALKYL BICYCLIC CARBOXYAMIDE COMPOUNDS
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This invention provides a compound of the formula (I): And their use for the treatment of disease conditions caused by overactivation of the VR1 receptor such as pain, or the like in mammal. This invention also provides a pharmaceutical composition compri
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Page/Page column 43
(2008/06/13)
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- α-Methylation at benzylic fragment of N-aryl-N′-benzyl ureas provides TRPV1 antagonists with better pharmacokinetic properties and higher efficacy in inflammatory pain model
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SAR studies for N-aryl-N′-benzyl urea class of TRPV1 antagonists have been extended to cover α-benzyl alkylation. Alkylated compounds showed weaker in vitro potencies in blocking capsaicin activation of TRPV1 receptor, but possessed improved pharmacokinetic properties. Further structural manipulations that included replacement of isoquinoline core with indazole and isolation of single enantiomer led to TRPV1 antagonists like (R)-16a with superior pharmacokinetic properties and greater potency in animal model of inflammatory pain.
- Gomtsyan, Arthur,Bayburt, Erol K.,Keddy, Ryan,Turner, Sean C.,Jinkerson, Tammie K.,Didomenico, Stanley,Perner, Richard J.,Koenig, John R.,Drizin, Irene,McDonald, Heath A.,Surowy, Carol S.,Honore, Prisca,Mikusa, Joe,Marsh, Kennan C.,Wetter, Jill M.,Faltynek, Connie R.,Lee, Chih-Hung
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p. 3894 - 3899
(2008/02/09)
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- Reaction of Oximes with Dimethyl Carbonate: A New Entry to 3-Methyl-4,5-disubstituted-4-oxazolin-2-ones
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The reaction of ketone oximes with dimethyl carbonate (DMC) carried out in an autoclave at 180-190 deg C and in the presence of K2CO3 yields 3-methyl-4,5-disubstituted-4-oxazolin-2-ones.The reaction can be applied to both aliphatic and aromatic ketone oximes, provided that a methylene group be present near the C=N bond.Nonoptimized yields range from 22 to 48percent.The reaction seems to be a sigmatropic rearrangement where DMC plays a key role in causing the initial N-methylation of the oximes.
- Marques, C. A.,Selva, M.,Tundo, P.,Montanari, F.
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p. 5765 - 5770
(2007/10/02)
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- ONE-STEP SYNTHESIS OF DIAZIRINES FROM O-TOSYL KETOXIMES AND ALKOXYAMINES
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The reaction of O-tosyloximes of acetone, hexafluoroacetone, and mesoxalic acid esters with alkoxyamines leads to the corresponding diazirines, while the reaction of benzophenone O-tosyloxime with methoxyamine gives only benzophenone O-methyloxime.O-Esters of acetoxime were isolated along with 3,3-dimethylazirine also in the reaction of O-tosylacetoxime with alkoxyamines.Nucleophilic attack of alkoxyamines on O-tosyloximes of mesoxalates is realized at the carbon atom of not only the C=O bond but also at the carbon atom of the C=O bond, and the latter leads to fragmentation of the O-tosyloxime to give N-alkoxycarbamates, a cyanocarbonate ester, and p-toluenesulfonic acid.In the presence of triethylamine, which blocks the C=N bond, the reaction of mesoxalate O-tosyloxime proceeds only via the fragmentation pathway.The mechanism of the formation of diazirines in the reaction of O-tosylketoximes with alkoxyamines is discussed.
- Shustov, G. V.,Tavakalyan, N. B.,Pleshkova, A. P.,Kostyanovskii, R. G.
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p. 600 - 605
(2007/10/02)
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