- An atypical easy reductive cleavage of the conjugated CC bond in 1,1′-disubstituted isoindigos under the action of aqueous hydrazine hydrate
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The reaction of diverse symmetrically-substituted isoindigo derivatives with 80% aqueous hydrazine hydrate is described. The influence of the structure of the substituent on either oxindole or isatin-3-hydrazone formation is discussed.
- Bogdanov, Andrei V.,Petrova, Alisa V.,Krivolapov, Dmitry B.,Mironov, Vladimir F.
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- 3-Carboxamide oxindoles as 1,3-C,N-bisnucleophiles for the highly diastereoselective synthesis of CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atom
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A simple and efficient strategy has been established for the synthesis of δ-lactam fused oxindoles via the Michael/N-hemiketalization cascade reaction of 3-carboxamide oxindoles and α,β-unsaturated trifluoromethyl ketones. A wide range of structurally novel CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atoms were obtained in moderate to good yields with excellent diastereoselectivities under mild conditions. This work represents the first example of a systematic study of 3-carboxamide oxindoles as 1,3-C,N bisnucleophiles.
- Zhao, Hongcai,Zhang, Zhengbing,Lu, Wenhua,Han, Pan,Wang, Wei,Jing, Linhai
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- Synthesis of Oxindole Derivatives via Intramolecular C–H Insertion of Diazoamides Using Ru(II)-Pheox Catalyst
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This work presented the efficient intramolecular aromatic C–H insertion of diazoacetamide. The 1a–1o diazo compounds (except for 1k) were converted into their corresponding oxindoles via an intramolecular C–H insertion reaction in the presence of a Ru catalyst. The Ru-Pheox catalyst was shown to be highly efficient in this transformation in terms of the regioselectivity, producing the desired products in excellent yield (99%). The efficiency of the Ru catalyst reached 580 (TON) and 156 min?1 (TOF).
- Phan Thi Thanh, Nga,Dang Thi Thu, Huong,Tone, Masaya,Inoue, Hayato,Iwasa, Seiji
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- Acylation of oxindoles using methyl/phenyl estersviathe mixed Claisen condensation - an access to 3-alkylideneoxindoles
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Predominantly, aggressive acid chlorides and stoichiometric coupling reagents are employed in the acylating process for synthesizing carbonyl tethered heterocycles. Herein, we report simple acyl sources,viz. methyl and phenyl esters, which acylate oxindolesviathe mixed Claisen condensation. This straightforward protocol is mediated by LiHMDS and KOtBu and successfully applied to a wide range of substrates. It is a noteworthy transformation that skips the stepwise generation of enolates and acylation, and the reaction is performed at a moderate temperature with no side reactions. This protocol produces the first examples ofortho-substituents in an aryl ring flanked with electron-donating and electron-withdrawing substrates. Interestingly, robust organometallic ferrocenyl methyl ester cleaved under these conditions with ease. Furthermore, biologically important Tenidap's analog was synthesized by this protocol.
- Gandhi, Thirumanavelan,Nagaraja, C. M.,Panyam, Pradeep Kumar Reddy,Rajeshwaran, Purushothaman,Sreedharan, Ramdas,Yadav, Saurabh
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p. 3843 - 3847
(2020/06/03)
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- Candida antarctica lipase-B-catalyzed kinetic resolution of 1,3-dialkyl-3-hydroxymethyl oxindoles
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Candida antarctica (CAL-B) lipase-catalyzed resolution of 1,3-dialkyl-3-hydroxymethyl oxindoles has been performed to obtain (R)-1,3-dialkyl-3-acetoxymethyl oxindoles with up to 99% ee and (S)-1,3-dialkyl-3-hydroxymethyl oxindoles with up to 78% ee using vinyl acetate as acylating agent and acetonitrile as solvent transforming (S)-3-allyl-3-hydroxymethyl oxindole to (3S)-1′-benzyl-5-(iodomethyl)-4,5-dihydro-2H-spiro[furan-3,3′-indolin]-2′-one. The optically active 3-substituted-3-hydroxymethyl oxindoles and spiro-oxindoles are among the key synthons in the synthesis of potentially biologically active molecules.
- Kumar, Naveen,Kumar, Akshay,Sahoo, Subash Chandra,Chimni, Swapandeep Singh
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p. 1377 - 1394
(2020/11/23)
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- Synthesis of 2-Oxindoles from Substituted Indoles by Hypervalent-Iodine Oxidation
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A practical conversion of indoles into the corresponding 2-oxindoles is achieved efficiently using a hypervalent iodine reagent. This oxidation is amenable to different substituted indoles, and allows the synthesis of a wide range of synthetically valuable substituted 2-oxindoles in up to 90 % yield. Furthermore, Ropinirole, a drug used to alleviate the symptoms of Parkinson's disease, was synthesized in three steps in an overall yield of 44 % using this method.
- Jiang, Xinpeng,Zheng, Cong,Lei, Lijun,Lin, Kai,Yu, Chuanming
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p. 1437 - 1442
(2018/04/06)
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- Method for directly synthesizing substituted 2-indolone by substituted indole under neutral condition
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The invention relates to a method for directly synthesizing substituted 2-indolone by substituted indole under the neutral condition. The method comprises the following steps of sequentially adding organic solvents and water according to the proportion of 1:1-1:20 at the room temperature; then, adding high-iodine reagents; raising the temperature to 40 to 160 DEG C; then, adding indole; performingreaction for 1 to 8 hours to obtain the substituted 2-indolone compounds. The method has the main innovation point that under the neutral condition, substituted 2-indolone is directly synthesized through indole oxidization; the use of strong acid reagents is avoided. The method has the advantages that the raw materials are cheap and can be easily obtained; the operation is simple and convenient;the substrate universality is high; the reaction yield is high, and the like.
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Paragraph 0044-0045
(2018/07/06)
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- Method for synthesizing indole-2-ketone compound
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The invention belongs to the technical field of organic chemical synthesis, and particularly relates to a method for synthesizing an indole-2-ketone compound. Indole-2-ketone compound synthesis is difficultly industrialized due to the problems of poor yield, cost and environmental protection in the prior art, the method includes the steps: taking a compound X as a catalyst in a hydrous organic solvent; performing reaction on indole and water under the condition of oxidizing agents to obtain the indole-2-ketone compound. The compound X is preferably iodine, and the indole-2-ketone compound is applicable to the field of organic synthesis and medicine.
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Paragraph 0079; 0081
(2018/11/03)
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- Cinchona-alkaloid-catalyzed enantioselective hydroxymethylation of 3-fluorooxindoles with paraformaldehyde
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Cinchona-alkaloid-catalyzed hydroxymethylation of 3-fluorooxindoles using paraformaldehyde as the C1 unit was achieved. A wide range of 3-fluorooxindoles was successfully reacted to give the corresponding 3-fluoro-3-hydroxymethyloxindoles with high efficiency and moderate to good enantioselectivity.
- Zhao, Jian-bo,Ren, Xinfeng,Zheng, Bu-quan,Ji, Jian,Qiu, Zi-bin,Li, Ya
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- Transition-metal-free Chemoselective Oxidative C?C Coupling of the sp3 C?H Bond of Oxindoles with Arenes and Addition to Alkene: Synthesis of 3-Aryl Oxindoles, and Benzofuro- and Indoloindoles
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A transition-metal (TM)-free and halogen-free NaOtBu-mediated oxidative cross-coupling between the sp3 C?H bond of oxindoles and sp2 C?H bond of nitroarenes has been developed to access 3-aryl substituted and 3,3-aryldisubstituted oxindoles in DMSO at room temperature in a short time. Interestingly, the sp3 C?H bond of oxindoles could also react with styrene under TM-free conditions for the practical synthesis of quaternary 3,3-disubstituted oxindoles. The synthesized 3-oxindoles have also been further transformed into advanced heterocycles, that is, benzofuroindoles, indoloindoles, and substituted indoles. Mechanistic experiments of the reaction suggests the formation of an anion intermediate from the sp3 C?H bond of oxindole by tert-butoxide base in DMSO. The addition of nitrobenzene to the in-situ generated carbanion leads to the 3-(nitrophenyl)oxindolyl carbanion in DMSO which is subsequently oxidized to 3-(nitro-aryl) oxindole by DMSO.
- Sattar, Moh.,Rathore, Vandana,Prasad, Ch. Durga,Kumar, Sangit
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supporting information
p. 734 - 743
(2017/04/13)
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- NBS-mediated dinitrogen extrusion of diazoacetamides under catalyst-free conditions: Practical access to 3-bromooxindole derivatives
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A synthetically useful transformation arises from NBS-mediated dinitrogen extrusion of N-aryl diazoacetamides under catalyst-free conditions, which gives 3-bromooxindoles in high to excellent yields with high selectivity via a non-carbene process.
- Wang, Xiangbo,Dong, Kuiyong,Yan, Bin,Zhang, Cheng,Qiu, Lihua,Xu, Xinfang
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p. 70221 - 70225
(2016/08/06)
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- Autoxidation/Aldol Tandem Reaction of 2-Oxindoles with Ketones: A Green Approach for the Synthesis of 3-Hydroxy-2-Oxindoles
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In the presence of tetrabutylammonium fluoride and molecular sieves (MS) 4 ? in DMF, an efficient autoxidation reaction of 2-oxindoles with ketones under air at room temperature has been developed. This approach may provide a green, practical, and metal-free protocol for a wide range of biologically important 3-hydroxy-3-(2-oxo-alkyl)-2-oxindoles.
- Zhang, Qing-Bao,Jia, Wen-Liang,Ban, Yong-Liang,Zheng, Yong,Liu, Qiang,Wu, Li-Zhu
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p. 2595 - 2598
(2016/02/27)
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- New Emitting Materials Based on HTL Moiety with High Hole Mobility for OLEDs
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New green emitting compounds based on tris(N-methylindolo)benzene (NMT), anthracene and pyrene were synthesized. NMT-An and NMT-Py were used as an emitting layer in OLED device to examine emitting property. OLED device containing NMT-An emitting layer and conventional hole transporting layer (HTL) of NPB was found to exhibit better characteristics compared to NMT-Py. And that device showed maximum EL emission at 502 nm and 550 nm, CIE coordinates (0.38, 0.48), and a luminance efficiency of 2.06 cd/A. Also when NMT and NMT-An were used as a HTL instead of NPB, the device including NMT-An emitter showed 2.67 cd/A and 2.29 cd/A in luminance efficiency.
- Kang, Hyeonmi,Lee, Hayoon,Shin, Hwangyu,Kang, Seokwoo,Kim, Beomjin,Park, Jongwook
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- Oxidative dimerization of 2-oxindoles promoted by KOtBu-I2: Total synthesis of (±)-folicanthine
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A transition-metal-free oxidative coupling of 2-oxindoles has been demonstrated in the presence of 1.2 equiv each of potassium tert-butoxide and iodine. The method yields a diverse range of structurally different homo- and heterodimerized 2-oxindoles bearing vicinal all-carbon quaternary centers of great synthetic importance. A radical-driven pathway has been tentatively proposed.
- Ghosh, Santanu,Chaudhuri, Saikat,Bisai, Alakesh
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p. 1373 - 1376
(2015/03/30)
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- New potent fluorescent analogues of strigolactones: Synthesis and biological activity in parasitic weed germination and fungal branching
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In this work we report the synthesis of new fluorescent analogues of strigolactones, their spectroscopic properties and the evaluation of their biological activity both on seeds of Orobanche aegyptiaca and on the AM fungus Gigaspora margarita. The synthes
- Prandi, Cristina,Occhiato, Ernesto G.,Tabasso, Silvia,Bonfante, Paola,Novero, Mara,Scarpi, Dina,Bova, Maria Elena,Miletto, Ivana
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experimental part
p. 3781 - 3793
(2011/09/16)
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