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.
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.
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.
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.
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.
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.
Transition-Metal-Free Synthesis of Heterobiaryls through 1,2-Migration of Boronate Complex
Paul, Swagata,Das, Kanak Kanti,Manna, Samir,Panda, Santanu
, 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.
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.
Pd-catalyzed C–H bond activation of Indoles for Suzuki reaction
Banerjee, Isita,Ghosh, Keshab Ch,Sinha, Surajit
, (2019/08/22)
Abstract: We present a practical method for Suzuki coupling by which unprotected or N-protected indoles may be selectively arylated in the C2-position through direct C–H bond activation by electrophilic Pd(TFA) 2 catalyst. The protocol is operationally simple as it is carried out in dioxane/water mixture, and air as the sole oxidant at room temperature. Various 2-arylated indoles were obtained in good yields. The protocol works for benzofuran, pyrrole and thiophene also. Graphic abstract: Selective C-2 arylation of heterocycles using Pd(II) catalyst via C–H activation was performed under ambient condition. C3–C2 migration of organopalladium intermediate controls the reaction pathway.[Figure not available: see fulltext.].
The controllable C2 arylation and C3 diazenylation of indoles with aryltriazenes under ambient conditions
Liu, Yonghong,Ma, Xia,Wu, Gengxin,Liu, Ziran,Yang, Xiang,Wang, Bin,Liu, Chenjiang,Zhang, Yonghong,Huang, Yan
supporting information, p. 9255 - 9259 (2019/06/17)
An efficient and regio-divergent method for both the C2 arylation and C3 diazenylation of C2,C3-unsubstituted indoles with aryltriazenes was developed. At room temperature, both reactions were carried out with HPF6/ionic liquids (ILs) as the promoter. The C2 arylation and C3 diazenylation activated by HPF6/ILs show remarkable reactivity, which results in corresponding products with yields of up to 99%. Notably, the practicality of the protocol was further demonstrated via gram-scale operations, late-stage modification and the reusability of the ILs.
