61843-43-4Relevant academic research and scientific papers
Corrigendum to: Aryl(triethyl)silanes for Biaryl and Teraryl Synthesis by Copper(II)-Catalyzed Cross-Coupling Reaction (Angew. Chem. Int. Ed., (2016), 55, (15787–15791), (10.1002/anie.201608667))
Komiyama, Takeshi,Minami, Yasunori,Hiyama, Tamejiro
, p. 8035 - 8035 (2017)
In this Communication, Table 3, entry 11, the correct product from the reaction of 2-(triethylsilyl)indole (6 b) with p-iodoanisole (4 a) was not 2-(p-methoxyphenyl)indole (7 ba) but N-(p-methoxyphenyl)indole [Eq. 1]. (Figure presented.) C2 arylation was achieved using substituted 2-(triethylsilyl)indoles. From the reaction of N-methyl-2-(triethylsilyl)indole with 4 a under standard conditions (reaction time was 22 h), N-methyl-2-(p-methoxyphenyl)indole was isolated in 52% yield after column chromatography [Eq. 2]. (Figure presented.) A corrected Supporting Information is provided along with this Corrigendum.
N-Hydroxyphthalimidyl diazoacetate (NHPI-DA): A modular methylene linchpin for the C-H alkylation of indoles
Chowdhury, Rajdip,Mendoza, Abraham
, p. 4532 - 4535 (2021/05/17)
Despite the extensive studies on the reactions between conventional diazocompounds and indoles, these are still limited by the independent synthesis of the carbene precursors, the specific catalysts, and the required multi-step manipulation of the products. In this work, we explore redox-Active carbenes in the expedited and divergent synthesis of functionalized indoles. NHPI-DA displays unusual efficiency and selectivity to yield insertion products that can be swiftly elaborated into boron and carbon substituents that are particularly problematic in carbene-mediated reactions.
Benzoic Acid-Promoted C2-H Borylation of Indoles with Pinacolborane
Zou, Youliang,Zhang, Binfeng,Wang, Li,Zhang, Hua
, p. 2821 - 2825 (2021/04/13)
A benzoic acid-promoted C2-H borylation of indoles with pinacolborane to afford C2-borylated indoles is developed. Preliminary mechanistic studies indicate BH3-related borane species formed via the decomposition of pinacolborane to be the probable catalyst. This transformation provides a prompt route toward the synthesis of diverse C2-functionalized indoles.
Synthesis of 2-Substituted Benzothio(seleno)phenes and Indoles via Ag-Catalyzed Cyclization/Demethylation of 2-Alkynylthio(seleno)anisoles and 2-Alkynyldimethylanilines
Cai, Tao,Feng, Chengjie,Shen, Fangqi,Bian, Kejun,Wu, Chunlei,Shen, Runpu,Gao, Yuzhen
, p. 653 - 656 (2020/12/23)
An Ag-catalyzed cyclization/demethylation of 2-alkynylthio(seleno)anisoles and 2-alkynyldimethylanilines is described and applied for the construction of valuable benzothio(seleno)phenes as well as indoles. Various 2-substituted benzothio(seleno)phenes and indoles were obtained in good to excellent yields under mild reaction conditions with low catalyst loading. An application of this new method is also exemplified with a concise synthesis of a bioactive molecule precursor. Furthermore, a conceivable reaction mechanism is proposed with supports from isotope-exchange experiments.
In Situ Preparation of Palladium Nanoparticles for C-2 Selective Arylation of Indoles in Agro-Waste Extract Based Mixed Solvents
Jin, Weiwei,Liu, Chenjiang,Liu, Tianxiang,Sun, Yajun,Wang, Bin,Wang, Rui,Xia, Yu,Zhang, Yonghong
supporting information, p. 2470 - 2473 (2021/06/25)
An efficient and practical method for the in situ generation of palladium nanoparticles was successfully established in a water extract of pomelo peel ash. The produced palladium nanoparticles were characterized by energy-dispersive X-ray spectroscopy elemental mapping, field emission scanning electron microscopy, high-resolution transmission electron microscope, X-ray powder diffraction, and showed high catalytic activity for selective C-2 arylation of indoles. A series of 2-arylindoles were smoothly installed in moderate to good yields through the direct palladium-catalyzed cross-coupling reactions of indoles and iodoarenes without external ligand, base, oxidant, and preinstallation directing group.
Transition-Metal-Free Synthesis of Heterobiaryls through 1,2-Migration of Boronate Complex
Paul, Swagata,Das, Kanak Kanti,Manna, Samir,Panda, Santanu
supporting information, p. 1922 - 1927 (2020/02/04)
The synthesis of a diverse range of heterobiaryls has been achieved by a transition-metal-free sp2–sp2 cross-coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl–heteroaryl boronate complex, which triggered 1,2-migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene, and indole are well tolerated. Finally, we have successfully demonstrated the gram scale synthesis of the intermediates for an anticancer drug and OLED material using our methodology.
Direct C-H bond activation: Palladium-on-carbon as a reusable heterogeneous catalyst for C-2 arylation of indoles with arylboronic acids
Bhattacharjee, Prantika,Bora, Utpal,Boruah, Purna K.,Das, Manash R.
, p. 7675 - 7682 (2020/06/09)
Direct C(sp2)-H bond functionalization of indoles with arylboronic acids is achieved using palladium supported on carbon as a reusable heterogeneous catalyst in the presence of an oxidant under mild conditions. The current protocol formed exclusive C-2 selective products without the aid of any ligand or directing group. The catalyst is reusable for up to four catalytic cycles with the retention of catalytic efficiency.
C2–H Arylation of Indoles Catalyzed by Palladium-Containing Metal-Organic-Framework in γ-Valerolactone
Anastasiou, Ioannis,Van Velthoven, Niels,Tomarelli, Elena,Lombi, Aurora,Lanari, Daniela,Liu, Pei,Bals, Sara,De Vos, Dirk E.,Vaccaro, Luigi
, p. 2786 - 2791 (2020/03/24)
An efficient and selective procedure was developed for the direct C2–H arylation of indoles using a Pd-loaded metal–organic framework (MOF) as a heterogeneous catalyst and the nontoxic biomass-derived solvent γ-valerolactone (GVL) as a reaction medium. The developed method allows for excellent yields and C-2 selectivity to be achieved and tolerates various substituents on the indole scaffold. The established conditions ensure the stability of the catalyst as well as recoverability, reusability, and low metal leaching into the solution.
Synthesis of 2-substituted indoles through cyclization and demethylation of 2-alkynyldimethylanilines by ethanol
Zhao, Guangkuan,Roudaut, Christelle,Gandon, Vincent,Alami, Mouad,Provot, Olivier
supporting information, p. 4204 - 4210 (2019/08/07)
Herein, we demonstrated that 2-alkynyldimethylamines easily cyclize in EtOH according to a 5-endo-dig annulation into 2-substituted indoles without the aid of any additives or any metal catalysts to activate the triple bond. Thus, a variety of functionalized 2-styrylindoles, 2-arylindoles, 2-alkynylindoles, and 2-alkylindoles were prepared in high to excellent yields according to an environmentally friendly protocol. The mechanism has been explored to better understand this eco-friendly access to 2-substituted indoles and DFT calculations rationalized the role of the solvent in this N-annulation/dealkylation process.
Preparation method for indole compound
-
Paragraph 0063-0064, (2019/12/25)
The invention provides a preparation method for an indole compound, and belongs to the technical field of preparation of heterocyclic compounds. The preparation method comprises the following steps: with 1,2-dichloromethane as a solvent, silver oxide as a catalyst and 2-ethynylaniline and derivatives thereof as raw materials, subjecting the raw materials to a complete reaction at 10 to 60 DEG C inthe presence of p-toluenesulfonic acid monohydrate, carrying out spin-drying so as to obtain a crude product, and carrying out column chromatographic separation so as to obtain a fine product namelythe indole compound. The preparation method provided by the invention has the advantages of short preparation steps, mild reaction conditions, high product yield and low cost, and provides a universalnovel method for preparation of the indole compound.
