- Raney nickel-induced 3-alkylation of oxindole with alcohols and diols
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New reaction conditions are described, which turn Wenkert's synthesis of 3-alkyloxindoles (Raney nickel-induced alkylation of oxindole with alcohols) into a reproducible and highly efficient synthetic tool. The method is also extended to the preparation o
- Volk, Balázs,Mezei, Tibor,Simig, Gyula
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- Iron-Catalyzed Borrowing Hydrogen C-Alkylation of Oxindoles with Alcohols
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A general and efficient iron-catalyzed C-alkylation of oxindoles has been developed. This borrowing hydrogen approach employing a (cyclopentadienone)iron carbonyl complex (2 mol %) exhibited a broad reaction scope, allowing benzylic and simple primary and secondary aliphatic alcohols to be employed as alkylating agents. A variety of oxindoles underwent selective mono-C3-alkylation in good-to-excellent isolated yields (28 examples, 50–92 % yield, 79 % average yield).
- Dambatta, Mubarak B.,Polidano, Kurt,Northey, Alexander D.,Williams, Jonathan M. J.,Morrill, Louis C.
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- Manganese-Catalyzed C(α)-Alkylation of Oxindoles with Secondary Alcohols via Borrowing Hydrogen
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A general and efficient C(α)-alkylation of oxindoles with unactivated secondary alcohols as alkylating agents catalyzed by a newly developed NNN-Mn(II) complex is reported. Mechanistic studies illustrate that the importance of the NH moiety in the complex and M-L cooperation play very important roles during the catalytic transformation.
- Rana, Jagannath,Nagarasu, Palaniyappan,Subaramanian, Murugan,Mondal, Akash,Madhu, Vedichi,Balaraman, Ekambaram
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- New One-Pot Synthesis of 3-Alkyl- and 3-(ω-Hydroxyalkyl)oxindoles from Isatins
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A new and efficient one-pot procedure has been developed for the synthesis of 3-alkyl- and 3-(ω-hydroxyalkyl)oxindoles from isatins by treatment with alcohols and diols in the presence of Raney nickel, under hydrogen atmosphere. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Volk, Balazs,Simig, Gyula
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- Electrochemical Umpolung C-H Functionalization of Oxindoles
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Herein, we present a general electrochemical method to access unsymmetrical 3,3-disubstituted oxindoles by direct C-H functionalization where the oxindole fragment behaves as an electrophile. This Umpolung approach does not rely on stoichiometric oxidants and proceeds under mild, environmentally benign conditions. Importantly, it enables the functionalization of these scaffolds through C-O, and by extension to C-C or even C-N bond formation.
- Pastor, Miryam,Vayer, Marie,Weinstabl, Harald,Maulide, Nuno
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p. 606 - 612
(2022/01/12)
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- Rapid Oxidation Indoles into 2-Oxindoles Mediated by PIFA in Combination with n-Bu4NCl ? H2O
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We report the development of a rapid approach for directly converting indoles into 2-oxindoles promoted by HOCl formed in situ from the combination of (bis(trifluoroacetoxy) iodo)benzene (PIFA) and n-Bu4NCl ? H2O. The procedure is widely functional group tolerant and provides 2-oxindoles in up to 95% yield within 5 min. The potential applications of the developed methodology are demonstrated by the gram-scale preparation of 3-methyl-2-oxindole (11 a), the one-pot two-step syntheses of spiro-oxindoles 26 a and 26 b, and the formal synthesis of (-)-folicanthine (2). (Figure presented.).
- Liang, Peng,Zhao, Hang,Zhou, Tingting,Zeng, Kaiyun,Jiao, Wei,Pan, Yang,Liu, Yazhou,Fang, Dongmei,Ma, Xiaofeng,Shao, Huawu
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supporting information
p. 3532 - 3538
(2021/06/09)
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- Iron-Catalyzed Oxidative Cross-Coupling of Phenols and Tyrosine Derivatives with 3-Alkyloxindoles
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In this study, a novel iron-catalyzed oxidative cross-coupling reaction between phenols and 3-alkyloxindole derivatives is reported. The efficient method, which is based on the FeCl3 catalyst and the t-BuOOt-Bu oxidant in 1,2-dichloroethane at 70 °C, affords 3-alkyl-3-(hydroxyaryl)oxindole compounds with a high degree of selectivity. The generality of the conditions was proven by reacting various substituted phenols, naphthols, and tyrosine derivatives with 3-alkyloxindoles. To apply the chemistry for the conjugation of tyrosine-containing short peptides with oxindolylalanine (Oia) derivatives, the reaction conditions were modified [Fe(O2CCF3)3 catalyst, t-BuOOt-Bu, HFIP, 70 °C], and amino acids with acid-stable N-protecting groups were used.
- Mintz, Tomer,More, Nagnath Yadav,Gaster, Eden,Pappo, Doron
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p. 18164 - 18178
(2021/12/17)
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- C-Alkylation of Various Carbonucleophiles with Secondary Alcohols under CoIII-Catalysis
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Oxindoles have been successfully α-alkylated under Cp*CoIII catalysis by a vast array of secondary alcohols, including cyclic, acyclic, symmetrical, and unsymmetrical, to produce C-alkylated oxindoles. This protocol was also extended to the α-alkylation of N,N-dimethyl barbituric acid and benzyl cyanides. The kinetic profile and other preliminary mechanistic investigations suggest a first-order reaction rate in oxindoles and catalysts. A plausible catalytic cycle is proposed on the basis of the kinetic profile, of other preliminary mechanistic investigations, and of previous mechanistic studies on similar transformations, whereas density functional theory calculations provide insight into the nature of the active species.
- Chakraborty, Priyanka,Garg, Nidhi,Manoury, Eric,Poli, Rinaldo,Sundararaju, Basker
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p. 8023 - 8031
(2020/08/21)
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- Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
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The construction of carboxylic acid compounds in a selective fashion from low value materials such as alkenes remains a long-standing challenge to synthetic chemists. In particular, β-addition to styrenes is underdeveloped. Herein we report a new electrosynthetic approach to the selective hydrocarboxylation of alkenes that overcomes the limitations of current transition metal and photochemical approaches. The reported method allows unprecedented direct access to carboxylic acids derived from β,β-trisubstituted alkenes, in a highly regioselective manner.
- Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
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supporting information
(2020/02/13)
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- Preparation method of 3-substituted oxidized indole and derivative
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The invention belongs to the technical field of organic chemistry and pharmaceutical chemistry and particularly relates to a method of preparing 3-substituted oxidized indole and a derivative. In themethod, with a 3-substituted indole derivative as a raw material and one or more of a tetrabutyl ammonium halide compound/sodium chloride/sodium iodide/potassium iodide as additives, and one or more of dichloromethane/1,2-dichloroethane/tetrahydrofurane/methylbenzene/1,4-dioxane/ethyl acetate/methanol are added as solvents; then one or more of [bis(trifluoroacetoxyl)iodine]benzene/iodosobenzene diacetate are added as oxidants in order to carry out a reaction with reaction temperature being controlled, thus producing the 3-substituted oxidized indole derivative. The method has gentle reaction conditions, simple operations, short reaction time and high yield, and is free of a metal catalyst and is environment-friendly.
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- Magnesium-Catalyzed Electrophilic Trifluoromethylation: Facile Access to All-Carbon Quaternary Centers in Oxindoles
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The first example of a magnesium-catalyzed direct trifluoromethylation of 3-substituted oxindoles using an electrophilic hypervalent iodine reagent is reported. The reaction proceeds under unprecedented mild conditions leading to the formation of an all-carbon quaternary center in oxindoles in high chemical yield and demonstrates excellent functional group tolerance. In addition to trifluoromethyl, other perfluoroalkyl groups can be introduced with similar level of efficacy. Mechanistic investigations are consistent with the involvement of a radical pathway. The chemical versatility of the obtained products is further illustrated through their conversion in situ into valuable organofluorine building blocks, making the protocol more widely applicable.
- Katayev, Dmitry,Kajita, Harutake,Togni, Antonio
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supporting information
p. 8353 - 8357
(2017/06/28)
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- Transition-Metal-Free C-H Hydroxylation of Carbonyl Compounds
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Transition metal and reductant free α-C(sp3)-H hydroxylation of carbonyl compounds are reported. This method is promoted by commercially available inexpensive KO-t-Bu and atmospheric air as an oxidant at room temperature. This unified strategy is also very facile for hydroxylation of various carbonyl compound derivatives to obtain quaternary hydroxyl compounds in excellent yield. A preliminary mechanistic investigation, supported by isotope labeling and computational studies, suggests the formation of a peroxide bond and its cleavage by in situ generated enolate.
- Chaudhari, Moreshwar B.,Sutar, Yogesh,Malpathak, Shreyas,Hazra, Anirban,Gnanaprakasam, Boopathy
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supporting information
p. 3628 - 3631
(2017/07/15)
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- A Facile Method for the Synthesis of 3-Alkyloxindole
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Benzylamine in combination with acetic acid was identified as a powerful catalyst for the condensation of oxindole with aldehydes, acetone or cyclic ketones. A variety of 3-alkyloxindoles could be readily prepared in 10 mmol scale via the sequential benzylamine acetate catalyzed condensation of oxindoles with aldehydes (or ketones) and conjugate reduction by NaBH4.
- Du, Tai-Ping,Zhu, Gang-Guo,Zhou, Jian
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p. 225 - 232
(2012/07/14)
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- CH activation and CH2 double activation of indolines by radical translocation: Understanding the chemistry of the indolinyl radical
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CH activation and CH2 double activation of indolines at C2 may be achieved efficiently through radical translocation. The fate of the C2 indolinyl radical is dictated by the substitution at C3. Fragmentation, cyclisation and tandem cyclisation reactions leading to indole, azaheterocycle and azapropellane formation, respectively, are reported. The Royal Society of Chemistry 2011.
- Harrowven, David C.,Stenning, Kerri J.,Whiting, Sally,Thompson, Toby,Walton, Robert
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supporting information; experimental part
p. 4882 - 4885
(2011/08/05)
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- Ruthenium-catalyzed alkylation of oxindole with alcohols
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(Chemical Equation Presented) An atom-economical and solvent-free catalytic procedure for the mono-3-alkylation of oxindole with alcohols is described. The reaction is mediated by the in situ generated catalyst from RuCl 3·xH2O and P
- Jensen, Thomas,Madsen, Robert
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supporting information; experimental part
p. 3990 - 3992
(2009/12/25)
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- Direct N-carbamoylation of 3-monosubstituted oxindoles with alkyl imidazole carboxylates
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(Chemical Equation Presented) Regioselective N-carbamoylation of oxindoles was achieved through the use of imidazole carboxylate reagents. This reaction provides ready access to N-carbamoyl-3-monosubstituted oxindoles.
- Trost, Barry M.,Zhang, Yong,Zhang, Ting
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supporting information; experimental part
p. 5115 - 5117
(2009/10/24)
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- Novel N-substituted alpha aminoacid amides as calcium channel modulators
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The compounds of formula I and derivatives thereof have been found to be active in tests that show modulation of voltage-dependent calcium channels, and are thus indicated for use in the treatment of diseases in which such modulation is beneficial, in par
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- Unusual Reactions of Magnesium Indolates with Benzenesulfonyl Chloride
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Grignard reagents from N-unsubstituted indoles and benzenesulfonyl chloride undergo reaction such as to produce unstable intermediates of β-chlorination and α-sulfonylation, which are transformed into oxindoles or substituted indoles.In the same reaction, yuehchukene (the naturally occurring dehydroprenylindole dimer) is converted into a spirooxindole, containing a strained four-membered ring, which is changed into a spirooxindole isomer with ring expansion on mild acid treatment.
- Wenkert, Ernest,Moeller, Peter D. R.,Piettre, Serge R.,McPhail, Andrew T.
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p. 3404 - 3409
(2007/10/02)
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