13228-39-2Relevant academic research and scientific papers
Atom Efficient Magnesiation of N-Substituted Alkyl Indoles with a Mixed Sodium-Magnesium Base
Stevens, Michael A.,Blair, Victoria L.
, p. 74 - 79 (2018)
This study presents the alkali metal mediated magnesiation (AMMMg) of three N-alkylated indoles with the mixed Na/Mg base [(TMEDA)Na(TMP)2Mg(CH2SiMe3)] 1 (TMEDA = N,N,N′,N′-tetramethylethylenediamine, TMP = 2,2,6,6-tetramethylpiperidine). All three magnesiated indoles have been successfully characterised by single-crystal X-ray diffraction and solution state NMR studies, whereas iodolysis and Pd-catalysed cross coupling have been investigated. The steric nature of the N-alkyl group changes the reactivity and efficiency of 1 to give either atom efficient disodium tetraindol-2-ylmagnesiates [(Na-TMEDA)2Mg(α-C9H8N)4] 2 and [(Na-TMEDA)2Mg(α-C10H11N)4] 3, or [(TMEDA)Na(TMP)(α-C11H12N)Mg(TMP)] 4, whereby only one indole molecule is selectively deprotonated.
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.
Discovery of New 4-Indolyl Quinazoline Derivatives as Highly Potent and Orally Bioavailable P-Glycoprotein Inhibitors
Chen, Zhe-Sheng,Dai, Qing-Qing,Li, Guo-Bo,Liu, Hong-Min,Liu, Hui,Wang, Bo,Wang, Shaomeng,Yu, Bin,Yuan, Shuo,Zhang, Jing-Ya,Zhang, Xiao-Nan,Zuo, Jia-Hui
, p. 14895 - 14911 (2021/10/12)
The major drawbacks of P-glycoprotein (P-gp) inhibitors at the clinical stage make the development of new P-gp inhibitors challenging and desirable. In this study, we reported our structure-activity relationship studies of 4-indolyl quinazoline, which led to the discovery of a highly effective and orally active P-gp inhibitor, YS-370. YS-370 effectively reversed multidrug resistance (MDR) to paclitaxel and colchicine in SW620/AD300 and HEK293T-ABCB1 cells. YS-370 bound directly to P-gp, did not alter expression or subcellular localization of P-gp in SW620/AD300 cells, but increased the intracellular accumulation of paclitaxel. Furthermore, YS-370 stimulated the P-gp ATPase activity and had moderate inhibition against CYP3A4. Significantly, oral administration of YS-370 in combination with paclitaxel achieved much stronger antitumor activity in a xenograft model bearing SW620/Ad300 cells than either drug alone. Taken together, our data demonstrate that YS-370 is a promising P-gp inhibitor capable of overcoming MDR and represents a unique scaffold for the development of new P-gp inhibitors.
Exploration of Biaryl Carboxylic Acids as Proton Shuttles for the Selective Functionalization of Indole C-H Bonds
Pi, Jing-Jing,Lu, Xiao-Yu,Liu, Jing-Hui,Lu, Xi,Xiao, Bin,Fu, Yao,Guimond, Nicolas
, p. 5791 - 5800 (2018/05/14)
A survey of diversely substituted 2-arylbenzoic acids were synthesized and tested for use as proton shuttle in the direct arylation of indoles with bromobenzenes. It was found that 3-ethoxy-2-phenylbenzoic acid gives superior yield and selectivity for this class of substrates.
A highly efficient and recyclable Fe3O4 magnetic nanoparticle immobilized palladium catalyst for the direct C-2 arylation of indoles with arylboronic acids
Zhang, Lei,Li, Pinhua,Liu, Can,Yang, Jin,Wang, Min,Wang, Lei
, p. 1979 - 1988 (2014/06/24)
A highly efficient Fe3O4 magnetic nanoparticle (MNP) immobilized palladium catalyst was prepared and applied to the direct C-2 arylation of indoles with arylboronic acids. The reactions generated the corresponding cross-coupling products in good yields. In addition, the supported catalyst with low loading (2.0 mol%) showed high stability and could be recovered and reused 8 times without significant loss of activity. The Royal Society of Chemistry 2014.
Rhodium(III)-catalyzed indole synthesis using N-N bond as an internal oxidant
Liu, Baoqing,Song, Chao,Sun, Chao,Zhou, Shuguang,Zhu, Jin
supporting information, p. 16625 - 16631 (2013/12/04)
We report herein a Rh(III)-catalyzed cyclization of N-nitrosoanilines with alkynes for streamlined synthesis of indoles. The synthetic protocol features a distinct internal oxidant, N-N bond, as a reactive handle for catalyst turnover, as well as a hitherto tantalizingly elusive intermolecular redox-neutral manifold, predicated upon C-H activation, for the formation of a five-membered azaheterocycle. The compatibility of seemingly dichotomous acidic and basic conditions ensures reaction versatility for multifarious synthetic contexts. The tolerance of an array of auxiliary functional groups potentially permits predefined, programmable substitution patterns to be incorporated into the indole scaffold. Comprehensive mechanistic studies, under acidic condition, support [RhCp*]2+ as generally the catalyst resting state (switchable to [RhCp*(OOCtBu)]+ under certain circumstance) and C-H activation as the turnover-limiting step. Given the variety of covalent linkages available for the nitroso group, this labile functionality is likely to be harnessed as a generic handle for strikingly diverse coupling reactions.
Direct palladium-catalyzed C-2 and C-3 arylation of indoles: A mechanistic rationale for regioselectivity
Lane, Benjamin S.,Brown, Meghann A.,Sames, Dalibor
, p. 8050 - 8057 (2007/10/03)
We have recently developed palladium-catalyzed methods for direct arylation of indoles (and other azoles) wherein high C-2 selectivity was observed for both free (NH)-indole and (NR)-indole. To provide a rationale for the observed selectivity ("nonelectrophilic" regioselectivity), mechanistic studies were conducted, using the phenylation of 1-methylindole as a model system. The reaction order was determined for iodobenzene (zero order), indole (first order), and the catalyst (first order). These kinetic studies, together with the Hammett plot, provided a strong support for the electrophilic palladation pathway. In addition, the kinetic isotope effect (KIEH/D) was determined for both C-2 and C-3 positions. A surprisingly large value of 1.6 was found for the C-3 position where the substitution does not occur (secondary KIE), while a smaller value of 1.2 was found at C-2 (apparent primary KIE). On the basis of these findings, a mechanistic interpretation is presented that features an electrophilic palladation of indole, accompanied by a 1,2-migration of an intermediate palladium species. This paradigm was used to design new catalytic conditions for the C-3 arylation of indole. In case of free (NH)-indole, regioselectivity of the arylation reaction (C-2 versus C-3) was achieved by the choice of magnesium base.
Photophysics of 2-Phenyl-3-indolocarbocyanine Dyes
Auweraer, Mark Van der,Zegel, Marc Van den,Boens, Noeel,Schryver, F. C. De,Willig, F.
, p. 1169 - 1175 (2007/10/02)
In this paper the photophysics of the perchlorate and chloride salts of N-ethyl- and N-octadecyl-2-phenyl-3-indolocarbocyanine have been investigated.Stationary fluorescence spectra and quantum yields of these dyes were measured in various solvents.The quantum yields in the homologous series of linear aliphatic alcohols, with viscosities ranging from 0.6 to 14 cP, followed a linear Oster-Nishijima relationship.The quantum yields in nonalcohol solvents were higher than in alcohols of the same viscosity.Fluorescence decay times were obtained with a mode-locked, synchronously pumped R6G dye-laser system with time-correlated single photon counting detection.The fluorescence decays of the dyes could be adequately described by a dual-exponential decay law with a short decay time between 35 and 1040 ps and a long decay time varying from 103 to 3210 ps.In nonbranched alcohols, both decay times followed a linear Oster-Nishijima relationship.The double-exponential decays were interpreted in terms of a cis-trans isomerism rather than as an effect of excited-state relation or ion pairing.The cis-trans isomerism already exists in the ground state and was also observed for 9-alkyl-substituted oxa- and thiacarbocyanines and for 1,3'-diethyl-4,2'-quinolyloxacarbocyanine.
Cyclisation indolique selon Bischler en presence d'acides de Lewis
Galons, Herve,Girardeau, Jean-Francois,Farnoux, Claude Combet,Miocque, Marcel
, p. 561 - 564 (2007/10/02)
In a comparative study of various catalysts (hydrochloric acid, Lewis acids) in the Bischler cyclization of α-aminoketones to indoles, aluminium chloride appears as the most active catalyst.Isomerization of β to α-indoles can be observed by raising the reaction temperature.The mechanism seems different from the one frequently suggested by most authors, since it does not affect intermediate aminoketones but indoles.
