2343-22-8Relevant academic research and scientific papers
Rhodium(III)-catalyzed direct regioselective synthesis of 7-substituted indoles
Song, Zengqiang,Samanta, Rajarshi,Antonchick, Andrey P.
, p. 5662 - 5665 (2013)
An efficient, atom-economic one-pot method was developed for the preparation of 7-substituted indoles via rhodium(III)-catalyzed oxidative cross-coupling. Regioselective olefination of indoline derivatives followed by one-pot subsequent oxidation provided the desired products in good to excellent yields.
Ru(ii)-Catalyzed C7-acyloxylation of indolines with carboxylic acids
De, Pinaki Bhusan,Banerjee, Sonbidya,Pradhan, Sourav,Punniyamurthy, Tharmalingam
, p. 5889 - 5898 (2018)
Ruthenium(ii)-catalyzed site-selective C7-acyloxylation of indolines with carboxylic acids is presented. The substrate scope and functional group tolerance are important practical features. The kinetic isotope studies suggest that C-H bond activation may be the rate-determining step.
Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
Liu, Shuyang,Tian, Miao,Bu, Xiubin,Tian, Hua,Yang, Xiaobo
supporting information, p. 7738 - 7744 (2021/05/07)
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.
Hydrogenation or Dehydrogenation of N-Containing Heterocycles Catalyzed by a Single Manganese Complex
Borghs, Jannik C.,Rueping, Magnus,Zubar, Viktoriia
supporting information, (2020/05/19)
A highly chemoselective base-metal catalyzed hydrogenation and acceptorless dehydrogenation of N-heterocycles is presented. A well-defined Mn complex operates at low catalyst loading (as low as 2 mol %) and under mild reaction conditions. The described catalytic system tolerates various functional groups, and the corresponding reduced heterocycles can be obtained in high yields. Experimental studies indicate a metal-ligand cooperative catalysis mechanism.
Manganese-Catalyzed Regioselective Dehydrogenative C-versus N-Alkylation Enabled by a Solvent Switch: Experiment and Computation
Borghs, Jannik C.,Zubar, Viktoriia,Zubar, Viktoriia,Azofra, Luis Miguel,Sklyaruk, Jan,Rueping, Magnus,Rueping, Magnus
supporting information, p. 4222 - 4227 (2020/06/04)
The first base metal-catalyzed regioselective dehydrogenative alkylation of indolines using readily available alcohols as the alkylating reagent is reported. A single air-and moisture-stable manganese catalyst provides access to either C3-or N-alkylated indoles depending on the solvent used. Mechanistic studies indicate that the reaction takes place through a combined acceptorless dehydrogenation and hydrogen autotransfer strategy.
Dual-Active-Sites Design of Co@C Catalysts for Ultrahigh Selective Hydrogenation of N-Heteroarenes
Zhang, Sai,Gan, Jie,Xia, Zhaoming,Chen, Xiao,Zou, Yong,Duan, Xuezhi,Qu, Yongquan
supporting information, p. 2994 - 3006 (2020/09/04)
The dual-active-sites Co@C catalyst provides a general powerful strategy to break the limitation of scaling relation on traditional metal surfaces and thus affords unprecedentedly selective hydrogenation of various N-heteroarenes as well as high activity and stability. A porous carbon shell not only allows H2 diffusion to Co sites for activation but also blocks accessibility of N-heteroarenes, and the hydrogenation of N-heteroarenes is achieved on carbon by the spilled hydrogen from Co sites. In addition, the presence of surface/subsurface carbon at the Co sites shows high anti-sulfur poisoning and anti-oxidant capability. Ideal heterogeneous metal hydrogenation catalysts are featured by simultaneously high activity, selectivity, and stability. Herein, we report a general yet powerful strategy to design and fabricate dual-active-sites Co@C core-shell nanoparticle for boosting selective hydrogenation of various N-heteroarenes. It can break the limitation of scaling relation on traditional metal surfaces, and thus afford unprecedentedly high selectivity, activity, and stability. Combining kinetics analysis and DFT calculations with multiple techniques directly unveil that the critical porous carbon shell with a pore size of 0.53 nm not only allows H2 diffusion to Co sites for activation and blocks accessibility of N-heteroarenes but also catalyzes hydrogenation of N-heteroarenes via hydrogen spillover from Co sites. In addition, the presence of surface/subsurface carbon at the Co sites shows high anti-sulfur poisoning and anti-oxidant capability. This work is valuable for guiding the design and manipulation of cost-effective and robust hydrogenation catalysts. Our research can provide an environmentally friendly approach to afford unprecedentedly selective N-heteroarenes hydrogenation, which will greatly reduce the resource and energy consumption and decrease the amount of waste discharge and water pollution. Therefore, these results could help in achieving the “Clean water and sanitation” goal in the 10 UN Sustainable Development Goals. Meanwhile, the products of N-heteroarenes hydrogenation are the core structural motifs in both fine and bulk chemicals, which will make our life more beautiful. Thus, our research also benefits the “Good health and well-being” goal.
Re-Catalyzed Annulations of Weakly Coordinating N-Carbamoyl Indoles/Indolines with Alkynes via C?H/C?N Bond Cleavage
Yang, Yunhui,Wang, Congyang
supporting information, p. 8245 - 8248 (2019/05/28)
Described herein are rhenium-catalyzed [3+2] annulations of N-carbamoyl indoles with alkynes via C?H/C?N bond cleavage, which provide rapid access to fused-ring pyrroloindolone derivatives. For the first time, the weakly coordinating O-directing group was successfully employed in rhenium-catalyzed C?H activation reactions, enabled by the unique catalytic trio of Re2(CO)10, Me2Zn and ZnCl2. Mechanistic studies revealed that aminozinc species plays an important role in the reaction. Based on the mechanistic understanding, a more powerful catalytic trio of Re2(CO)10, [MeZnNPh2]2 and Zn(OTf)2 was devised and applied successfully in the [4+2] annulations of indolines and alkynes affording pyrroloquinolinone derivatives.
Design, synthesis and biological evaluation of novel 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole triazole derivatives as potent TRPV1 antagonists
Li, Jinyu,Nie, Cunbin,Qiao, Yue,Hu, Jing,Li, Qifei,Wang, Qiang,Pu, Xiaohui,Yan, Lin,Qian, Hai
, p. 433 - 445 (2019/06/18)
Reported herein is the design, synthesis, and pharmacologic evaluation of a class of TRPV1 antagonists constructed on 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole as A-region and triazole as B-region. The SAR analysis indicated that 2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole analogues displayed excellent antagonism of hTRPV1 activation by capsaicin and showed better potency compared to the corresponding dihydroindole analogues. Optimization of this design led to the eventual identification of 2-((1-(2-(trifluoromethyl)phenyl)-1H-1,2,3-triazol-4-yl)methyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole (6g), a potent TRPV1 antagonist. In vitro, using cells expressing recombinant human TRPV1 channels, 6g displayed potent antagonism activated by capsaicin (IC50 = 0.075 μM) and only partially blocked acid activation of TRPV1. In vivo, 6g exhibited good efficacy in capsaicin-induced and heat-induced pain models and had almost no hyperthermia side-effect. Furthermore, pharmacokinetic studies revealed that compound 6g had a superior oral exposure after oral administration in rats. To understand its binding interactions with the receptor, the docking study of 6g was performed in rTRPV1 model and showed an excellent fit to the binding site. On the basis of its superior profiles, 6g could be considered as the lead candidate for the further development of antinociceptive drugs.
Sustainable Radical Cascades to Synthesize Difluoroalkylated Pyrrolo[1,2-a]indoles
Huang, Honggui,Yu, Menglin,Su, Xiaolong,Guo, Peng,Zhao, Jia,Zhou, Jiabing,Li, Yi
, p. 2425 - 2437 (2018/02/23)
We disclose herein a photocatalytic difluoroalkylation and cyclization cascade reaction of N-(but-2-enoyl)indoles with broad substrate scopes in up to 90% isolated yield. This method provides sustainable and efficient access to synthesize difluoroalkylated pyrrolo[1,2-a]indoles with a quaternary carbon center under mild conditions.
Expedient cobalt(II)-catalyzed site-selective C7-arylation of indolines with arylboronic acids
De, Pinaki Bhusan,Pradhan, Sourav,Banerjee, Sonbidya,Punniyamurthy, Tharmalingam
supporting information, p. 2494 - 2497 (2018/03/21)
Cobalt(ii)-catalyzed pyrimidyl directing group-assisted C7 arylation of indolines with arylboronic acids has been developed using Mn(OAc)2·4H2O as an oxidant. The use of cobalt(ii)-PCy3 as a catalyst and broad substrate scope are the important practical features.
