Electrophilic Substitution Reaction Of Indoles Research Articles

Xanthan sulfuric acid: An efficient and biodegradable solid acid catalyst for the synthesis of bis(indolyl)methanes under solvent-free conditions

Abstract Xanthan sulfuric acid (XSA) is found to be an efficient catalyst for the electrophilic substitution reaction of indole with aromatic aldehydes to afford the corresponding bis(indolyl)methanes at room temperature under solvent-free conditions. The catalyst was characterized for the first time with the help of powder XRD, SEM–EDX and DSC–TGA. The attractive features of this green, new methodology are excellent yield of products, clean reaction profile, reusability of the catalyst, energy sustainable protocol, simple experimental and easier work-up procedures.

Boron trifluoride supported on nano-SiO2: an efficient and reusable heterogeneous catalyst for the synthesis of bis(indolyl)methanes and oxindole derivatives

Boron trifluoride supported on nano-SiO2 was used as an efficient and heterogeneous catalyst for the electrophilic substitution reaction of indole with various aromatic aldehydes and isatins in methanol to afford the corresponding bis(indolyl)methanes and oxindole derivatives in high yields at room temperature and under reflux conditions, respectively. The catalyst can be reused several times without loss of its catalytic activity.

Synthesis of Bisindolylmethanes and Their Cytotoxicity Properties

Polymer supported dichlorophosphate (PEG-OPOCl2) is an efficient green catalyst for the electrophilic substitution reaction of indole with aromatic aldehydes, in neat condition, to afford an excellent yield of bis(indolyl) methanes with short reaction time, at room temperature. The synthesized compounds and their anti-cancer activity are evaluated.

Synthesis of bis(indolyl)methanes using molten N-butylpyridinium bromide

A simple and rapid protocol has been developed for the synthesis of bis (indolyl)methane compounds in excellent yields using molten N -butyl-pyridinium bromide as a solvent and a working catalyst for the reaction. Synthesis of bis (indolyl)methane compounds were accomplished at moderate experimental conditions of temperature and ambient pressure, also involving an electrophilic substitution reaction of indoles with several aromatic aldehydes. The derivatives were confirmed with mass and other usual spectroscopic techniques. A discussion on plausible mechanism for the reaction is also presented.

Indion Ina 225H resin as a novel, selective, recyclable, eco-benign heterogeneous catalyst for the synthesis of bis(indolyl)methanes

Indion Ina 225H, is a heterogeneous, selective, recyclable, and eco-benign catalyst for liquid phase electrophilic substitution reactions of indoles with aldehydes to afford the corresponding bis(indolyl)methanes in excellent yields in short reaction time. The versatility of this method has been proved with a wide range of aliphatic and aromatic aldehydes with various stereo-electronic factors. This method shows much better selectivity between aldehydes and ketones. The methodology is well demonstrated toward the synthesis of biologically active bis(indolyl)methanes viz, vibrioindole, 4-(di(1H-indol-3-yl)methyl)benzene-1,2-diol and streptindole. The catalyst can be recovered and reused for several runs without loss of activity.

ChemInform Abstract: Room‐Temperature Synthesis of Diindolylmethanes Using Silica‐Supported Sulfuric Acid as a Reusable Catalyst under Solvent‐Free Conditions.

Abstract Efficient electrophilic substitution reactions of indoles with various aromatic and aliphatic aldehydes were carried out using a catalytic amount of H2SO4 · SiO2 under solvent-free conditions to afford the corresponding bis(indolyl)methanes in excellent yields.

Eutectic salts promote green synthesis of bis(indolyl) methanes

A convenient and rapid method for the electrophilic substitution reaction of indoles with carbonyl compounds has been developed by using deep eutectic solvent as green and reusable catalysts to afford the corresponding bis(indolyl) methanes in excellent yields at room temperature under mild reaction conditions.

Efficient, rapid synthesis of bis(indolyl)methane using ethyl ammonium nitrate as an ionic liquid

A simple and rapid protocol has been developed for an efficient synthesis of bis(indolyl)methane in excellent yields using ethyl ammonium nitrate (EAN) as reusable ionic liquid at room temperature. The protocol involves an electrophilic substitution reaction of indoles with several aldehydes.

Facile synthesis of bis(indolyl)methanes using iron(III) phosphate

A new, convenient and high yielding procedure for the preparation of bis(indolyl)methanes in glycerol by electrophilic substitution reaction of indole with aldehydes in the presence of catalytic amount of FePO4 (5.0 mol%) as a highly stable and reusable catalyst is described.

ChemInform Abstract: Electrophilic Substitution Reaction of Indole. Part 24. Synthesis, Characterization, and Crystal Structure of a Novel Heterocyclic Compound.

AbstractThe reaction of indole (I) with cyclohexanone (II) in the presence of boron trifluoride etherate results in the formation of the novel spiro compound (III) together with the known compound (IV).

Surfactant-assisted synthesis of bis(indolyl)methanes in water

Abstract An environmentally friendly synthesis method for bis(indolyl)methanes has been developed in the presence of sodium lauryl ether sulfate (SLES), electrophilic substitution reactions of indoles with aldehydes were accomplished in water as solvent at room temperature without any Bronested or Lewis acid catalysts.

Room-Temperature Synthesis of Diindolylmethanes Using Silica-Supported Sulfuric Acid as a Reusable Catalyst Under Solvent-Free Conditions

Efficient electrophilic substitution reactions of indoles with various aromatic and aliphatic aldehydes were carried out using a catalytic amount of H2SO4 · SiO2 under solvent-free conditions to afford the corresponding bis(indolyl)methanes in excellent yields.

Electrophilic substitution reaction of indole, part XXIV: Synthesis, characterization, and crystal structure of a novel heterocyclic compound

AbstractThe reaction of indole with cyclohexanone in the presence of the Lewis acid, boron trifluoride diethyl etherate, resulted in the synthesis of a novel and interesting product (1) in addition to the bis(indolyl)methane system (2). The structure of this novel compound has been determined by NMR (1H and 13C) and X‐ray crystal structure analysis. Compound 1 is a (1:2) addition reaction product of indole with cyclohexanone. The spiro six‐membered ring is in the classic chair conformation. An epoxide bridge at C‐4a/C‐10b and the two hydroxyl groups at C‐5a, C‐10a are all on the same side of the central five membered ring. J. Heterocyclic Chem., (2011).

ChemInform Abstract: Trichloroisocyanuric Acid‐Catalyzed Reaction of Indoles: An Expeditious Synthesis of Bis‐Indolyl, Tris‐Indolyl, Di(bis‐indolyl), Tri(bis‐indolyl), and Tetra(bis‐indolyl)methane under Solid‐State Conditions.

Trichloroisocyanuric acid is found to be an efficient catalyst for the electrophilic substitution reactionof indole with aldehydes/ketones to afford the corresponding bis-indolyl, tris-indolyl, di(bis-indolyl),tri(bis-indolyl), and tetra(bis-indolyl)methanes under solid-state conditions by pulverization-activationmethod at room temperature with excellent yields. The remarkable features of this new procedure arehigh conversions, shorter reaction times, cleaner reaction profiles, and simple experimental and work-upprocedures.

A highly efficient synthesis of oxindoles using a functionalized silica gel as support for indium(III) acetylacetonate catalyst in an aqueous-acetonitrile medium

Aminopropylsilica gel (APSG) was obtained by the modification of silica gel with 3-aminopropyltriethoxy silane. The indium(III) acetylacetonate complex was then subsequently anchored to yield In(acac) 3-bonded silica gel (In(acac) 3-APSG). The structure was investigated and confirmed by surface area (BET), elemental and thermogravimetric analyses, FT-IR, 13C-CPMAS spectral studies and inductively coupled plasma mass spectrometry technique (ICP-MS). The new In(acac) 3-APSG material was tested in the synthesis of oxindoles derivatives that were synthesized via the electrophilic substitution reaction of indoles with various isatins in water. The catalyst is highly stable and recyclable for several times. The work-up procedure is very simple and oxindoles were obtained in high yields.

Trichloroisocyanuric acid‐catalyzed reaction of indoles: An expeditious synthesis of bis‐indolyl, tris‐indolyl, di(bis‐indolyl), tri(bis‐indolyl), and tetra(bis‐indolyl)methane under solid‐state conditions

Abstract magnified image Trichloroisocyanuric acid is found to be an efficient catalyst for the electrophilic substitution reaction of indole with aldehydes/ketones to afford the corresponding bis‐indolyl, tris‐indolyl, di(bis‐indolyl), tri(bis‐indolyl), and tetra(bis‐indolyl)methanes under solid‐state conditions by pulverization‐activation method at room temperature with excellent yields. The remarkable features of this new procedure are high conversions, shorter reaction times, cleaner reaction profiles, and simple experimental and work‐up procedures. J. Heterocyclic Chem., (2010).

ChemInform Abstract: A Convenient Method of Synthesis of Bis-indolylmethanes: Indium Trichloride Catalyzed Reactions of Indole with Aldehydes and Schiff′s Bases.

Abstract Anhydrous indium trichloride (InCl3) is found to catalyze the electrophilic substitution reaction of indole with aromatic aldehydes and Schiff's bases which resulted in an efficient synthesis of bis-indolylmethanes in good to excellent yield.

Ruthenium-catalyzed efficient routes to oxindole derivatives

Ruthenium-catalyzed preparation of oxindoles from one-pot trimerization of indoles under oxidative conditions and from electrophilic substitution reaction of indoles with isatins or isatin-derived imines under very mild reaction conditions is reported.

An eco-friendly procedure for the efficient synthesis of bis(indolyl)methanes in aqueous media

A new, convenient and high yielding procedure for the preparation of bis(indolyl)methanes in water by electrophilic substitution reaction of indoles with different carbonyl compounds in the presence of a catalytic amount of [Cu(3,4-tmtppa)](MeSO 4) 4 (1 mol%) as a highly stable and reusable catalyst is described. This procedure has also been applied successfully for the preparation of bis(pyrazole-5-ols) and dipyrromethanes.

Facile Synthesis of Bis(indolyl)methanes Using LaCl3 · 7H2O as a Mild and Efficient Catalyst in Molten Salt Media

Efficient electrophilic substitution reaction of indole with various carbonyl compounds were carried out using a catalytic amount of LaCl3 · 7H2O in molten tetraethylammonium chloride as an ionic liquid to afford the corresponding bis(indolyl)methanes in excellent yields.