948-65-2

Usage

Uses

Used in Pharmaceutical Industry:
2-Phenylindole is used as a reactant for the preparation of oxopyrrolidine analogs via iodine-catalyzed Markovnikov addition, which are potential anticancer immunomodulators. It also serves as a reactant for the synthesis of tryptophan dioxygenase inhibitors, such as pyridyl-ethenyl-indoles, which have potential applications in cancer therapy.
Used in Plastics Industry:
2-Phenylindole is used as a stabilizer in PVC-plastic products, specifically α-phenylindole, to enhance their durability and performance.
Used in Organic Chemistry:
2-Phenylindole is utilized as a reactant in the preparation of various compounds, such as organic light-emitting diodes (OLEDs), anti-inflammatory agents, and potential cyclooxygenase-1 (COX-1)/cyclooxygenase-2 (COX-2) inhibitors. It also plays a role in the development of agents for cancer and malaria therapy, as well as antifungal and antibacterial agents.
Used in Fluorescent Probes:
2-Phenylindole is used in the creation of fluorescent probes, which are essential tools in various scientific research and diagnostic applications.
Used in Chemical Reactions:
2-Phenylindole serves as a reactant in difluorohydroxylation reactions and Mannich-type reactions, contributing to the synthesis of a wide range of chemical compounds.

Preparation

2-phenylindole is prepared by condensing phenylhydrazine and acetophenone, and then closing the ring in the presence of zinc chloride. or it can be prepared by heating bromoacetophenone with excess aniline, or heating N-(2-methylphenyl)benzamide and sodium ethoxide at 360-380℃ in isolation from air.

Synthesis Reference(s)

Tetrahedron Letters, 33, p. 1459, 1992 DOI: 10.1016/S0040-4039(00)91646-0Journal of Heterocyclic Chemistry, 29, p. 1085, 1992 DOI: 10.1002/jhet.5570290509

InChI:InChI=1/C14H10N.K/c1-2-6-11(7-3-1)14-10-12-8-4-5-9-13(12)15-14;/h1-10H;/q-1;+1

Upstream product

• 26216-91-1 2-phenyl-2,3-dihydro-1H-indole 
• 1749-19-5 phenyl(1-phenylethylidene)amine 
• 4212-33-3 2-(2-nitrophenyl)-1-phenylethanone 
• 584-70-3 N-benzoyl-2-methylaniline 
• 141-52-6 sodium ethanolate 
• 5877-55-4 N-benzylidene-2-methylaniline 
• 92060-79-2 2,α'-dinitro-stilbene 
• 861360-42-1 3-(3-phenyl-indol-1-ylmethyl)-phenol 
• 34143-86-7 N-((E)-benzylidene)-o-toluidine 
• 5883-81-8 2-anilinoacetophenone 
• 636-21-5 o-toluidine hydrochloride 
• 142-04-1 aniline hydrochloride 
• 45497-73-2 aniline hydroiodide 
• 542-11-0 aniline hydrobromide 

Downstream Products

• 76869-06-2 2-phenyl-3-piperidinomethyl-indole 
• 4662-03-7 2-phenylindole-3-acetic acid 
• 102704-40-5 rac-3-(2-nitro-1-phenylethyl)-2-phenyl-1H-indole 
• 132594-38-8 (2-phenyl-indol-3-yl)-glyoxylic acid dimethylamide 
• 102318-27-4 (2-phenyl-indol-3-yl)-glyoxylic acid piperidide 
• 102003-06-5 4-[(2-phenyl-indol-3-yl)-oxoacetyl]-morpholine 
• 102754-29-0 (2-phenyl-indol-3-yl)-glyoxylic acid-(benzyl-methyl-amide) 
• 103278-21-3 (2-phenyl-indol-3-yl)-glyoxylic acid diphenylamide 
• 4771-06-6 2-phenyl-3-nitro-1H-indole 
• 102705-32-8 7-ethyl-2-phenyl-1H-indole 
• 25365-71-3 2-phenyl-1H-indol-3-carboxaldehyde 
• 59280-67-0 3-chloro-2-phenyl quinoline 
• 31054-05-4 2-phenyl-3-(4'-tolylimino)-3H-indole 
• 102590-84-1 3-(2-nitro-1-phenyl-propyl)-2-phenyl-indole 

Relevant academic research and scientific papers

Gold-Catalyzed Synthesis of Dibenzo[1,5]diazocines from β-(2-Aminophenyl)-α,β-ynones

β-(2-Aminophenyl)-α,β-ynones afforded exclusively challenging dibenzo[1,5]diazocines by means of (JonPhosAuNCMe)SbF6 catalysis. In contrast with the known gold-catalyzed reaction path of 2-alkynylanilines that leads to indoles, ynones underwent an auto intermolecular hydroamination. This process resulted finally in the formation of an eight-membered ring, likely through a selective 8-exo-dig intramolecular hydroamination that prevailed over the possible cyclocondensation reaction (that would result in the formation of 4-aminoquinoline derivatives). The easy availability of β-(2-aminophenyl)-α,β-ynones and the simple cyclization procedure make this approach suitable for the preparation of a wide range of useful dibenzodiazocines. The methodology can be extended to the use of β-(2-aminophenyl)-α,β-ynoates as substrates. (Figure presented.).

Evaluation of antioxidant activity and cytotoxicity of polyfluorinated diarylacetylenes and indoles toward human cancer cells

A large series of polyfluorinated diarylacetylenes and indoles was evaluated for antitumor activity in MCF-7, RPMI 8226, T98 G, HCT 116 human cancer cells and for cytotoxicity effect on HEK-293, WI-38, LMTK, AG 17 normal mammalian cell lines. It was found that with the increased number of fluorine atoms on the benzene ring of the compounds, their cytotoxicity increases, reaching a maximum in case of the perfluorinated structures. Polyfluorinated diarylacetylenes containing three fluorine atoms and trifluoromethyl and amino groups in one aryl ring, inhibit the proliferation of human myeloma RPMI 8226 and human breast cancer MCF-7 cells. Indoles showed more pronounced cytotoxicity as compared with their arylacetylene precursors. Compounds I9, I11, and I13 were found to have a high growth-inhibitory activity toward the human cancer cell lines tested, with half-inhibitory concentrations (IC50) of 1–10 μM. The structures of these compounds are characterized by complete fluorination of the benzene part of the indole core and the presence of an aromatic moiety at the 2nd position of the five-membered ring. Further, DNA fragmentation and Annexin V-FITC/PI staining assays confirm that I9 – I11 induce apoptosis. Mutagenic and antioxidant properties of the polyfluorinated indoles and of selected diarylacetylenes were also studied. On a Salmonella tester strain, it was demonstrated that the compounds are good antioxidants.

A Cascade Synthesis of Hetero-arylated Triarylmethanes Through a Double 5-endo-dig Cyclization Sequence

A sequential two-step method for the synthesis of hetero-arylated triarylmethanes through a Ag-catalyzed sequential double cyclization–nucleophilic addition cascade is described. This methodology basically involves an initial 5-endo-dig cyclization of o-alkynyl anilines to provide 2-substituted indole derivatives, which then react with 2-(2-enynyl)-pyridines to afford indolizine-containing unsymmetrical triarylmethanes through another 5-endo-dig cyclization.

Synthesis of C2-Phosphorylated Indoles via Metal-Free 1,2-Phosphorylation of 3-Indolylmethanols with P(O)-H Species

An efficient and practical method for synthesis of C2-phosphorylated indoles has been disclosed via a metal-free 1,2-phosphorylation of 3-indolylmethanols with H-phosphine oxides or H-phosphonates. This alternative protocol features a broad substrate scope with respect to both 3-indolylmethanols derived from isatins, acyclic α-keto amide, α-keto ester, 1,2-diketone and simple ketones and H-phosphine oxides or H-phosphonates, moderate to high yields and mild reaction conditions. Mechanistic studies indicate that this reaction proceeds via an unusual direct 1,2-addition pathway, in which the existence of an electron-withdrawing group adjacent to the hydroxyl group of 3-indolylmethanols plays a decisive role. (Figure presented.).

Ga(OTf)3-Catalyzed Temperature-Controlled Regioselective Friedel-Crafts Alkylation of Trifluoromethylated 3-Indolylmethanols with 2-Substituted Indoles: Divergent Synthesis of Trifluoromethylated Unsymmetrical 3,3′-and 3,6′-Bis(indolyl)methanes

An unprecedented Ga(OTf)3-catalyzed, temperature-controlled regiodivergent alkylation of 2-substituted indoles with trifluoromethylated 3-indolylmethanols is described that provides structurally diverse unsymmetrical 3,3′- and 3,6′-bis(indolyl)methanes with a CF3-containing quaternary carbon center in good to excellent yields under mild conditions. In addition, this present protocol could be successfully extended to the synthesis of difluoromethylated 3,3′- and 3,6′-bis(indolyl)methanes with excellent efficiency.

Enhancement of gold catalytic activity and stability by immobilization on the surface of graphene

The catalytic performance of gold complexes is evaluated at the molecular level and when supported onto reduced graphene oxide (rGO). Gold complexes of general formula [(NHC)AuX] catalyse the synthesis of indoles via intramolecular hydroamination reaction of alkynes. The catalytic properties of the molecular gold complexes are highly improved when supported onto graphene. Faster reaction rates and higher catalyst stability are observed for the immobilized gold complexes. The use of graphene as support of molecular complexes has a positive benefit in the catalytic gold properties in terms of activity and stability.

SYNTHESIS OF 2-SUBSTITUTED INDOLES

2-Substituted indoles are obtained upon the cyclocondensation of (2-R-2-oxoethyl)trimethylammonium bromides.

Evaluation of PVP/Au nanocomposite fibers as heterogeneous catalysts in indole synthesis

Electrospun nanocomposite fibers consisting of crosslinked polyvinylpyrrolidone (PVP) chains and gold nanoparticles (Au NPs) were fabricated, starting from highly stable PVP/Au NP colloidal solutions with different NP loadings, followed by thermal treatment. Information on the morphological characteristics of the fibers and of the embedded Au NPs was obtained by electron microscopy. Cylindrical, bead-free fibers were visualized by Scanning Electron Microscopy (SEM) while Transmission Electron Microscopy (TEM) and Energy Diffraction X-ray (EDX) analysis supported the presence of Au NPs within the fibers and gave information on their morphologies and average diameters. These materials were briefly evaluated as heterogeneous catalytic supports for the gold-catalyzed intramolecular cyclisation of 2-(phenylethynyl)aniline to form 2-phenyl-1H-indole. The performance of the gold catalyst was strongly dependent on the Au NP size, with the system containing the smallest Au NPs being the more effective. Moreover, a slight drop of their catalytic efficiency was observed after three consecutive reaction runs, which was attributed to morphological changes as a consequence of fiber merging.

Three-component Au—Chitosan—SiO2 systems as heterogeneous catalysts for intramolecular cyclization of 2-(2-phenylethynyl)aniline

A series of three-component heterogeneous catalysts Au—Ch—SiO2 with Ch for chitosan was prepared. The size of gold nanoparticles immobilized on the chitosan matrix depends on the method of sample preparation. The particles with the size 2. The catalysts were tested in the intramolecular cyclization reaction of 2-(2-phenylethynyl)aniline to for 2-phenylindole. The maximum conversion of 2-(2-phenylethynyl)aniline (25% within 35 h) was obtained on the Au(0.4%)—Ch(2.9%)/SiO2 catalyst.

Stereoselective Construction of Methylenecyclobutane-Fused Indolines through Photosensitized [2+2] Cycloaddition of Allene-Tethered Indole Derivatives

Irradiation of 1-(hexa-4,5-dienoyl)indole derivatives in the presence of an aromatic ketone by a high-pressure mercury lamp through Pyrex glass gave the corresponding cyclized products stereoselectively in high yields. The major part of the products was an all-cis-fused methylenecyclobutane-type compound produced through [2+2] cycloaddition, accompanied by small amounts of alkynes via 1,5-hydrogen transfer of a biradical intermediate. Among a range of aromatic ketones, 3′,4′-dimethoxyacetophenone was found to sensitize the substrate quite effectively.