101125-32-0Relevant articles and documents
Structure Ligation Relationship of Amino Acids for the Selective Indole C?H Arylation Reaction: L-Aspartic acid as Sustainable Alternative of Phosphine Ligands
Lokhande?, Shyam Kumar,Vaidya?, Gargi Nikhil,Satpute, Dinesh Parshuram,Venkatesh, Ashwini,Kumar, Sanjeev,Kumar, Dinesh
, p. 2857 - 2863 (2020)
The Structure Ligation Relationship (SLR) of free amino acids (AAs) under Pd-catalysis were examined for the chemo- and regio-selective indole C?H arylation reactions. While the majority of AAs were minor or ineffective, the L-aspartic acid (L-Asp) stands out promising to deliver high-value C3-arylated indoles with excellent chemo- (C vs N) and regioselectivity (C3 vs C2) with high functional group tolerance. Thus, the protocol offers a cost-effective and sustainable alternative of phosphine-based ligands for the indole C3?H arylation reactions. Preliminary mechanistic investigations suggested the simultaneous involvement of ?NH2, α-CO2H, and β-CO2H functionalities of L-Asp and found critical for its ligation efficiency. The developed catalytic system was compatible with the tandem decarboxylation/arylation procedure for the chemoselective synthesis of 3-aryl indoles. (Figure presented.).
A micellar catalysis strategy applied to the Pd-catalyzed C-H arylation of indoles in water
Vaidya, Gargi Nikhil,Fiske, Sneha,Verma, Hansa,Lokhande, Shyam Kumar,Kumar, Dinesh
, p. 1448 - 1454 (2019)
The selective control over multiple competing C-H sites would enable straightforward access to functionalized indoles. In this context, we report here a modular and selective C-H arylation of indoles following the micellar catalysis approach using the third generation "designer" surfactant SPGS-550-M in the presence of 1 mol% of [(cinnamyl)PdCl]2 under mild conditions. Thus, access to high value C-arylated (C-3 and C-2) indoles was achieved fulfilling the "triple bottom line philosophy" of green chemistry. The nature of the phosphine ligand was found to be critical for achieving site-selectivity, DPPF and DPPP being the most effective in promoting the arylation at C3-H and C2-H, respectively. The reaction is scalable and offers high chemo- (C vs. N) and regio-selectivity (C-3 vs. C-2) with a wide range of functional group tolerance. The surfactant aqueous solution can be recycled and reused without compromising on product yields.
Synthesis of indoles by intermolecular cyclization of unfunctionalized nitroarenes and alkynes: one-step synthesis of the skeleton of fluvastatin
Ragaini, Fabio,Ventriglia, Flavia,Hagar, Mohamed,Fantauzzi, Simone,Cenini, Sergio
, p. 2185 - 2189 (2009)
The addition of Ru3(CO)12, dimethyl carbonate, or both to the reaction mixture improves the selectivity of the palladium/phenanthroline-catalyzed reaction of nitroarenes, arylalkynes, and CO to give 3-arylindoles. When 4-fluorophenyl
Direct C3-Selective Arylation of N-Unsubstituted Indoles with Aryl Chlorides, Triflates, and Nonaflates Using a Palladium-Dihydroxyterphenylphosphine Catalyst
Yamaguchi, Miyuki,Hagiwara, Ryoya,Gayama, Kanami,Suzuki, Kohei,Sato, Yusuke,Konishi, Hideyuki,Manabe, Kei
, p. 10902 - 10912 (2020/09/23)
A palladium-dihydroxyterphenylphosphine (DHTP) catalyst was successfully applied to the direct C3-arylation of N-unsubstituted indoles with aryl chlorides, triflates, and nonaflates. This catalyst showed C3-selectivity, whereas catalysts with other structurally related ligands exhibited N1-selectivity. Complex formation between the lithium salts of the ligand and the indole is assumed to accelerate the arylation at the C3 position. Reactions using 3-alkylindoles afforded 3,3-disubstituted indolenines, which can be further converted to the corresponding indoline derivatives.
Iron-Promoted Construction of Indoles via Intramolecular Oxidative C-N Coupling of 2-Alkenylanilines Using Persulfate
Li, Yudong,Li, Yuehui,Luo, Shuping,Wang, Menglan,Wu, Qing-An
, p. 3085 - 3090 (2019/08/07)
Indole scaffold synthesis relies primarily on oxidative C-H amination of N-protected alkenylanilines for C-N intramolecular cyclization reactions. Herein, for the first time, without N-protection, various readily prepared 2-alkenylanilines were transformed into the desired indole products in good yields by using K 2 S 2 O 8 as oxidant in the presence of catalytic amounts of FeF 2. The K 2 S 2 O 8 /FeF 2 system offers a direct and benign synthetic route to 3-arylindoles and it is applicable to a wide range of substituted indoles including drug intermediates.
