4679-87-2Relevant academic research and scientific papers
Electrochemical Umpolung C-H Functionalization of Oxindoles
Pastor, Miryam,Vayer, Marie,Weinstabl, Harald,Maulide, Nuno
, p. 606 - 612 (2022/01/12)
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.
Manganese-Catalyzed C(α)-Alkylation of Oxindoles with Secondary Alcohols via Borrowing Hydrogen
Rana, Jagannath,Nagarasu, Palaniyappan,Subaramanian, Murugan,Mondal, Akash,Madhu, Vedichi,Balaraman, Ekambaram
supporting information, p. 627 - 634 (2021/04/02)
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.
Rapid Oxidation Indoles into 2-Oxindoles Mediated by PIFA in Combination with n-Bu4NCl ? H2O
Liang, Peng,Zhao, Hang,Zhou, Tingting,Zeng, Kaiyun,Jiao, Wei,Pan, Yang,Liu, Yazhou,Fang, Dongmei,Ma, Xiaofeng,Shao, Huawu
supporting information, p. 3532 - 3538 (2021/06/09)
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.).
Iron-Catalyzed Oxidative Cross-Coupling of Phenols and Tyrosine Derivatives with 3-Alkyloxindoles
Mintz, Tomer,More, Nagnath Yadav,Gaster, Eden,Pappo, Doron
, p. 18164 - 18178 (2021/12/17)
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.
Harnessing Applied Potential: Selective β-Hydrocarboxylation of Substituted Olefins
Alkayal, Anas,Buckley, Benjamin R.,Malkov, Andrei V.,Montanaro, Stephanie,Tabas, Volodymyr,Wright, Iain A.
supporting information, (2020/02/13)
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.
C-Alkylation of Various Carbonucleophiles with Secondary Alcohols under CoIII-Catalysis
Chakraborty, Priyanka,Garg, Nidhi,Manoury, Eric,Poli, Rinaldo,Sundararaju, Basker
, p. 8023 - 8031 (2020/08/21)
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.
Iron-Catalyzed Borrowing Hydrogen C-Alkylation of Oxindoles with Alcohols
Dambatta, Mubarak B.,Polidano, Kurt,Northey, Alexander D.,Williams, Jonathan M. J.,Morrill, Louis C.
, p. 2345 - 2349 (2019/05/16)
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).
Preparation method of 3-substituted oxidized indole and derivative
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, (2018/06/26)
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.
Magnesium-Catalyzed Electrophilic Trifluoromethylation: Facile Access to All-Carbon Quaternary Centers in Oxindoles
Katayev, Dmitry,Kajita, Harutake,Togni, Antonio
supporting information, p. 8353 - 8357 (2017/06/28)
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.
Transition-Metal-Free C-H Hydroxylation of Carbonyl Compounds
Chaudhari, Moreshwar B.,Sutar, Yogesh,Malpathak, Shreyas,Hazra, Anirban,Gnanaprakasam, Boopathy
supporting information, p. 3628 - 3631 (2017/07/15)
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.
