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)](MeSO₄)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.     

Efficient synthesis of bis(indolyl)methanes,bispyrazoles and biscoumarins using 4-sulfophthalic acid

Research on Chemical Intermediates - 4-Sulfophthalic acid (4-H3SPA) solution 50 wt% in H2O has been effectively catalyzed the synthesis of a series of biologically relevant...     

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

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.     

Ionic liquid promoted synthesis of bis(indolyl) methanes

1-benzyl-3-methyl imidazolium hydrogen sulphate [bnmim][HSO₄] was found to be an effective catalyst for the condensation reaction of indoles and derivatives with benzaldehydes in microwave irradiation with lower reaction time and higher yields to give bis(indolyl) methanes.      

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.     

A versatile and practical synthesis of bis(indolyl)methanes/bis(indolyl)glycoconjugates catalyzed by trichloro-1,3,5-triazine

A practical and efficient electrophilic substitution reaction of indoles with a variety of aldehydes was carried out using catalytic trichloro-1,3,5-triazine (10 mol %) in acetonitrile to furnish the corresponding bis(indolyl)methanes in excellent yields. Similarly, sugar derived aldehydes gave hitherto unknown bis(indolyl)glycoconjugates in very good yields.     

Synthesis,antibacterial and anti-inflammatory activity of bis(indolyl)methanes

A series of bioactive bis(indolyl)methanes are synthesized by one-pot green reaction of indole with various substituted aldehydes by microwave irradiation under solvent free conditions. The antibacterial activity against Staphylococcus aureus and anti-inflammatory activity of the synthesized bis(indolyl)-methanes are evaluated in vitro and compared to standard drugs tetracycline and diclofenac, respectively. The majority of the compounds showed good antibacterial and anti-inflammatory activity. Interestingly, compounds 3j, 3i, 3k and 3g exhibited much higher anti-inflammatory activity than the standard diclofenac drug and thus qualify for clinical trials to be used as an anti-inflammatory compound.     

Tetrabutylammonium tribromide as efficient catalyst in the synthesis of bis(indolyl)methanes

An efficient procedure has been developed for the synthesis of bis(indolyl)methane derivatives by condensation of aldehydes with indole in the presence of tetrabutylammonium tribromide as catalyst.     

A mild synthesis of bis(indolyl)methanes using a deep eutectic solvent

Deep eutectic solvents (such as the combination of urea and choline chloride) are effective solvents/organocatalysts for the condensation of indole and aryl or alkenyl aldehydes to form bis(indolyl)methanes. The reaction conditions are quite mild and do not require additional Bronsted or Lewis acid catalyst, though they fail with ketones or aliphatic aldehydes. Given the inexpensive, non-toxic, and recyclable nature of the DES, these reaction conditions are simple and highly environmentally friendly.     

Efficient synthesis of bis(indolyl)methanes catalyzed by(PhCH2PPh3)+Br3-under solvent-free conditions

<正>Benzyltriphenylphosphonium tribromide(BTPTB) has been applied as an efficient catalyst for the preparation of bis(indolyl)-methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.     

Molecular iodine-catalyzed efficient and highly rapid synthesis of bis(indolyl)methanes under mild conditions

Highly rapid and efficient electrophilic substitution reactions of indoles with various aldehydes and ketones were carried out using I₂ in CH₃CN to afford the corresponding bis(indolyl)methanes in excellent yields.     

Synthesis of bis(indolyl)methanes under catalyst-free and solvent-free conditions

Abstract

Condensation of indole with aromatic aldehydes has been carried out without using any catalyst and solvent to give bis(indolyl)methanes.     

Base-promoted three-component cascade approach to unsymmetrical bis(indolyl)methanes

Here we report a base-catalyzed reaction of two different indoles with aldehydes under heating to produce unsymmetrical bis(indolyl)methanes (BIMs), in which one of the indole ring must be N-substituted. Mixture of EtOH-H₂O is used as solvent. The reaction did not give symmetrical BIMs of N-substituted indoles or N–H indoles. However, traces of latter were formed in few cases, especially when electron-rich aldehydes were used. Diversely substituted indoles and aldehydes were used for the reaction. The reaction proceeds via 3-indolylalcohol, which we confirmed through isolation. The method also gives good yield on multigram scale reaction.     

An efficient and clean synthesis of bis(indolyl)methanes in a protic solvent at room temperature

Electrophilic substitution reactions of indoles with various aldehydes were carried out in a protic solvent at room temperature in the absence of any other catalyst to afford bis(indolyl)-methanes in excellent yields.     

Copper nitrate trihydrate catalyzed efficient synthesis of bis(indolyl)methanes in acetonitrile at room temperature

A catalytic amount of easily available and inexpensive Cu(NO₃)₃.3H₂O (10 mol%) enables electrophilic substitution reaction of indole with structurally divergent aldehydes in acetonitrile to afford the corresponding bis(indolyl)methanes in moderate to excellent yields (65‐98%) at ambient temperature. The reaction is highly chemoselective and applicable only to aldehydes and not to ketones.     

Hexamethylenetetraamine-Bromine Catalyzed Rapid and Efficient Synthesis of Bis(indolyl)methanes

Summary. Highly rapid and convenient syntheses of bis(indolyl)methanes in excellent yields were carried out using the inexpensive and easily available catalyst, hexamethylenetetraamine-bromine (HMTAB). Mild reaction conditions, short reaction times, and excellent yields are important features of this method.     

Iron(III)(salen)Cl as an efficient catalyst for synthesis of bis(indolyl)methanes

[Fe(III)(salen)]Cl (salen = N,N′-ethylenebis(salicylimine)) is an efficient catalyst for the electrophilic substitution of indole with carbonyl compounds to afford the corresponding bis(indolyl)methanes in good yields in molten tetrabutylammonium bromide as an ionic liquid. Notable features of this new procedure are shorter reaction times, cleaner reaction profiles, and simple experimental and work-up procedures.     

Synthesis of bis(indolyl) methanes using aluminium oxide(acidic) in dry media

<正>Heterogeneous catalyst aluminium oxide(acidic) is found to be an effective catalyst for the solvent-free condensation reaction of indole with aldehydes in microwave irradiation with shorter reaction time and higher yields.     

An efficient synthesis of bis(indolyl)methanes and N,N'-alkylidene bisamides by Silzic under solvent free conditions

An operationally simple and green method for the synthesis of a wide range of bis(indolyl)methanes,and N,N'-alkylidene bisamides under mild conditions,with excellent yields using Silzic,has been developed.This improved method furnishes in good yields bis(indolyl)methanes derivatives starting from indole and aldehydes,or ketones,and N,N'-alkylidene bisamides derivatives starting from acetamide and aldehydes.The catalytic system was reused up to three times with the same efficiency.