1038826-06-0Relevant articles and documents
Divergent Reactivity in Pd-Catalyzed [3,3]-Sigmatropic Rearrangement of Allyloxy- and Propargyloxyindoles Revealed by Computation and Experiment
Gutierrez, Osvaldo,Hendrick, Charles E.,Kozlowski, Marisa C.
, p. 6539 - 6543 (2018)
Detailed computational (DFT) studies of the palladium(II)-catalyzed Claisen rearrangement of 2-allyloxy- and propargyloxyindoles revealed an unexpected divergent mode of reactivity. Subsequent experimental kinetic isotope effects are in accord with the me
Water-medium C-H activation over a hydrophobic perfluoroalkane-decorated metal-organic framework platform
Huang, Yuan-Biao,Shen, Min,Wang, Xusheng,Huang, Ping,Chen, Ruiping,Lin, Zu-Jin,Cao, Rong
, p. 1 - 7 (2016)
The use of water as reaction medium in the heterogeneous activation of C-H bonds has numerous advantages in terms of environmental benign, safety and cost efficiency impact. However, it is severely hampered because the reactants are difficult to dissolve in water and contact with the active sites of heterogeneous catalysts. Herein, we choose perfluoroalkane-functionalized mesoporous metal-organic framework (MOF) NU-1000 as a hydrophobic platform to encapsulate ultrafine palladium nanoparticles (Pd NPs) for C-H activation in water. The resultant Pd NPs stabilized by the perfluoroalkane exhibited high activity and regioselectivity in the direct C-H arylation of indoles in water. The introduction of perfluoroalkane chains into the mesoporous pores of NU-1000 provides hydrophobic surfaces to facilitate access of the reactants to the active sites to guarantee the high activity.
Direct palladium-catalyzed C-3 arylation of free (NH)-indoles with aryl bromides under ligandless conditions
Bellina, Fabio,Benelli, Francesca,Rossi, Renzo
, p. 5529 - 5535 (2008)
(Chemical Equation Presented) A new method for the efficient, practical, and highly regioselective direct palladium-catalyzed C-3 arylation of free (NH)-indole and its electron-rich 1-unsubstituted derivatives under ligandless conditions is described. The reactions, which are run outside a glovebox without purification of solvent and reagents, involve treatment of free (NH)-indoles with activated, unactivated, and deactivated aryl bromides in refluxing toluene in the presence of K2CO3 as the base and a catalyst system consisting of a combination of Pd(OAc)2 and benzyl(tributyl)ammonium chloride. The experimental results are consistent with a catalytic cycle based on an electrophilic palladation pathway at the 3-position of 1-indolyl potassium salts.
Synthesis and antimycobacterial activity of 3-phenyl-1h-indoles
Abbadi, Bruno Lopes,Basso, Luiz Augusto,Bizarro, Cristiano Valim,Dornelles, Maiele,Duarte, Lovaine,Etchart, Renata Jardim,Lourega, Rogério Vescia,Macchi, Fernanda Souza,Machado, Pablo,Neves, Christiano Ev,Perelló, Marcia Alberton,Rambo, Raoní S.,Silva, Fernanda Fries,Sperotto, Nathalia
, (2021/08/31)
Tuberculosis has been described as a global health crisis since the 1990s, with an estimated 1.4 million deaths in the last year. Herein, a series of 20 1H-indoles were synthesized and evaluated as in vitro inhibitors of Mycobacterium tuberculosis (Mtb) g
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 (2020/06/09)
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.).
Catalytic Au(i)/Au(iii) arylation with the hemilabile MeDalphos ligand: Unusual selectivity for electron-rich iodoarenes and efficient application to indoles
Rodriguez, Jessica,Zeineddine, Abdallah,Sosa Carrizo, E. Daiann,Miqueu, Karinne,Saffon-Merceron, Nathalie,Amgoune, Abderrahmane,Bourissou, Didier
, p. 7183 - 7192 (2019/08/07)
The ability of the hemilabile (P,N) MeDalphos ligand to trigger oxidative addition of iodoarenes to gold has been thoroughly studied. Competition experiments and Hammett correlations substantiate a clear preference of gold for electron-enriched substrates both in stoichiometric oxidative addition reactions and in catalytic C-C cross-coupling with 1,3,5-trimethoxybenzene. This feature markedly contrasts with the higher reactivity of electron-deprived substrates typically encountered with palladium. Based on DFT calculations and detailed analysis of the key transition states (using NBO, CDA and ETS-NOCV methods in particular), the different behavior of the two metals is proposed to result from inverse electron flow between the substrate and metal. Indeed, oxidative addition of iodobenzene is associated with a charge transfer from the substrate to the metal at the transition state for gold, but opposite for palladium. The higher electrophilicity of the gold center favors electron-rich substrates while important back-donation from palladium favors electron-poor substrates. Facile oxidative addition of iodoarenes combined with the propensity of gold(iii) complexes to readily react with electron-rich (hetero)arenes prompted us to apply the (MeDalphos)AuCl complex in the catalytic arylation of indoles, a challenging but very important transformation. The gold complex proved to be very efficient, general and robust. It displays complete regioselectivity for C3 arylation, it tolerates a variety of functional groups at both the iodoarene and indole partners (NO2, CO2Me, Br, OTf, Bpin, OMe?) and it proceeds under mild conditions (75 °C, 2 h).
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
supporting information, p. 1448 - 1454 (2019/03/26)
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.
Pyridylmethylamine–Palladium Catalytic Systems: A Selective Alternative in the C?H Arylation of Indole
Perato, Serge,Large, Benjamin,Lu, Qiao,Gaucher, Anne,Prim, Damien
, p. 389 - 392 (2017/02/15)
A highly efficient pyridylmethylamine-Pd alternative catalytic system for the C?H arylation of indole was explored. Variously substituted aryl groups were regio- and chemoselectively installed at the indole nucleus by using barium hydroxide as the base. The method was found to be efficient even in the presence of hindered coupling partners and Pd-reactive bonds.
Palladium-catalyzed direct denitrogenative C-3-arylation of 1H-indoles with arylhydrazines using air as the oxidant
Chen, Yongxin,Guo, Shuaibo,Li, Kangning,Qu, Jinpeng,Yuan, Hua,Hua, Qiuru,Chen, Baohua
supporting information, p. 711 - 715 (2013/03/29)
A novel palladium-catalyzed approach to direct C-3-arylation of 1H-indoles with arylhydrazines using air as the oxidant via C-N bond cleavage has been developed. Various substituents are tolerated in this system in moderate to good yields. This reaction could also be compatible with a larger scale. Thus, this strategy using arylhydrazines as arylating reagents provides a powerful method for constructing substituted 3-aryl-1H-indoles. Copyright
"on water" direct and site-selective Pd-catalysed C-H arylation of (NH)-indoles
Joucla, Lionel,Batail, Nelly,Djakovitch, Laurent
supporting information; experimental part, p. 2929 - 2936 (2011/02/22)
This communication describes the development of a versatile catalytic system based on palladium(II) acetate/bis(diphenylphosphino)methane [Pd(OAc)2/dppm] that works "on water" giving site-selective C-H arylation of (NH)-indoles without protecting or directing groups. Remarkably, the control of regioselectivity was achieved by small changes in the "extra-catalytic" base/halide partners. These innovative methodologies allow a high-yielding access to both C2 and C3-arylindoles, as well as 2,3-diarylindoles, and display high chemo/regioselectivities and structural versatility with regard to either indole or aryl moieties. Copyright