One-pot three-component synthesis of bis(indolyl)methanes under solvent-free condition using heteropoly-11-tungsto-1-vanadophosphoric acid supported on natural clay as catalyst

One-pot three-component condensation reaction of two moles of indole and one mole of aromatic aldehyde for the synthesis of bis(indolyl)methanes in the presence of new catalytic material, heteropoly-11-tungsto-1-vanadophosphoric acid, H₄[PV^VW₁₁O₄₀] (HPV) supported on activated natural clay under solvent-free reaction condition has been proposed. The catalysts were prepared by incipient wetness impregnation method. The physicochemical characterizations of the HPV (20%) supported on natural clay (HPVAC-20) have also been discussed. Solvent-free heterogeneous reaction condition, simple workup procedure, short reaction time, high yield of products, and reusability of the catalyst are the advantages of the protocol.     

Synthesis of bis(indolyl) methanes catalyzed by Schiff base-Cu(Ⅱ) complex

Schiff base-Cu(Ⅱ) complex is found to be an effective catalyst for the condensation reaction of indole with aldehydes using ethanol as the solvent.The characterization of the catalysts was carried out using XRD and FT-IR.     

CuBr2‐Catalyzed Synthesis of Bis(indolyl)methanes

Abstract

Copper(II) bromide is found to be an efficient catalyst for the electrophilic substitution reaction of indole with aldehydes to afford the corresponding bis(indolyl)methanes in good yields.     

Novel method for synthesis of unsymmetrical bis(indolyl)alkanes catalyzed by ceric ammonium nitrate (CAN) under ultrasonic irradiation

The reaction of indole with (1H-indol-3-yl)(alkyl) methanol was catalyzed efficiently by ceric ammonium nitrate under ultrasonic irradiation to afford the unsymmetrical bis(indolyl)alkane in good to excellent yields.     

Antimony Trichloride Catalyzed Condensation of Indole and Carbonyl Compounds: Synthesis of Bis(indolyl)methanes

A mild and efficient condensation reaction of indoles with various aldehydes and ketones under catalysis of antimony trichloride (SbCl₃) afforded biologically important bis(indolyl)methanes in good yield. The structures of all the newly synthesized compounds were elucidated on the basis of IR, ¹H NMR and mass spectral data.     

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.     

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.     

Oxalic acid as a catalyst for efficient synthesis of bis-（indolyl）methanes,and 14-aryl- 14H-dibenzo[a,j]xanthenes in water

A simple, efficient, and environment benign route was developed for the preparation of bis-（indolyl）methanes and 14-aryl-14H- dibenzo[aj]xanthenes from condensation of various aromatic aldehydes or ketones with indole, and 2-naphthol, respectively, using oxalic acid catalyst in aqueous medium. Use of cheap and easily available catalyst, better yields and simple reaction protocol are the advantages of the present method.     

Oxalic acld as a catalyst for efficient synthesis of bis-(indolyl)methanes,and 14-aryl-14H-dibenzo[a,j]xanthenes in water

A simple,efficient,and environment benign route was developed for the preparation of bis-(indolyl)methanes and 14-aryl-14H-dibenzo[a,j]xanthenes from condensation of various aromatic aldehydes or ketones with indole,and 2-naphthol,respectively,using oxalic acid catalyst in aqueous medium.Use of cheap and easily available catalyst,better yields and simple reaction protocol are the advantages of the present method.     

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.     

α‐Chymotrypsin‐Catalyzed Synthesis of Bis(indolyl)alkanes in Water

A novel methodology for the synthesis of bis(indolyl)methanes by the reaction of aromatic aldehydes and indole in water has been developed, and a series of desired products were obtained in moderate to excellent yields (from 65% to 97%) using 1.2 mg/mL α‐chymotrypsin as biocatalyst.     

基于龙胆苦苷的二吲哚甲烷类拟单萜吲哚生物碱类似物合成及其抗肿瘤、逆转紫杉醇耐药活性研究

以环烯醚萜类化合物龙胆苦苷为合成模块,利用拟单萜吲哚生物碱的仿生合成途径和组合化学的研究思路,与色胺类衍生物(吲哚结构的活性单元片段)通过缩合反应,首次合成了23个二吲哚甲烷类拟单萜吲哚生物碱类似物。利用核磁共振波谱(NMR)和高分辨质谱(HRMS)等谱学手段对合成化合物的结构进行了表征,并初步评价了其抗肿瘤活性和逆转耐药活性。活性结果表明,化合物4i脱掉糖基保护基后的化合物5i对3种肿瘤细胞系(TE-1,CAL-62和FaDu)的抑制作用强于阳性对照盐酸阿霉素(Dox)。通过与紫杉醇的联合用药,发现部分化合物如4m、4n、4o、4r等能够有效降低人肺癌细胞紫杉醇耐药株A549/Taxol对紫杉醇的耐药性,具有良好的逆转耐药潜力。     

对甲苯磺酸催化三吲哚烷基化合物的合成

室温下,吲哚与3-吲哚甲醛在对甲苯磺酸的催化下高收率得到三吲哚烷基化合物,所有产物的结构经1H NMR,IR和HR-MS表征。     

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.     

Cellulose sulfuric acid: reusable catalyst for solvent-free synthesis of bis(indolyl)methanes at room temperature

Abstract

Bis(indolyl)methanes were synthesized from indole and aldehydes under solvent-free conditions using cellulose sulfuric acid (CSA) as a catalyst at room temperature. CSA is easily prepared and it was also found that this catalyst could be recovered quantitatively and reused without much loss of catalytic activity.     

Green Protocol for the Synthesis of Bisindolylmethanes and Evaluation of Their Antimicrobial Activities

A simple, efficient, and ecofriendly procedure for the preparation of bis(indolyl)methanes via electrophilic substitution reactions of 2-phenylindoles with aldehydes is described. The reaction takes place in the presence of glacial acetic acid and a catalytic amount of anhydrous ferric chloride. All the synthesized compounds have been characterized by elemental analysis and spectral data (IR and ¹H NMR). They have also been evaluated for their antibacterial and antifungal activities, and some of them have shown promising results against S. aureus, E. coli, A. flavus, and A. niger.     

One-pot conversion of aromatic compounds to the corresponding bis(indolyl)methanes by the Vilsmeier–Haack reaction

Various electron-rich aromatics could be smoothly converted into the corresponding bis(indolyl)methanes in good to moderate yields by treatment of electron-rich aromatics with POCl₃ and DMF, followed by treatment with indole at room temperature. The present article is the first report on a novel metal-free one-pot method for the preparation of bis(indolyl)methanes from electron-rich aromatics.     

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

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.     

3-Amino-5-mercapto-1,2,4-triazole-functionalized Fe3O4 magnetic nanocomposite as a green and efficient catalyst for synthesis of bis(indolyl)methane derivatives

A core–shell Fe₃O₄@silica magnetic nanocomposite functionalized with 3-amino-5-mercapto-1,2,4-triazole (Fe₃O₄/SiO₂/PTS/AMTA) was prepared using Fe₃O₄ with silica layer, and its surface was modified with 3-amino-5-mercapto-1,2,4-triazole. The novel synthesized magnetite nanocomposite was characterized using various techniques. The catalytic activity of Fe₃O₄/SiO₂/PTS/AMTA was demonstrated in the synthesis of bis(indolyl)methane derivatives under solvent-free conditions. Some of the bis(indolyl)methane derivatives were synthesized through one-pot, three-component reaction of 1 mol of various benzaldehydes or ketones with 2 mol of indole in the presence of Fe₃O₄/SiO₂/PTS/AMTA in good to excellent isolated yields. In addition, the catalyst could be recovered and used for several reaction runs without loss of catalytic activity. The stability of recycled catalyst was investigated. This method has some advantages including experimental simplicity, good to excellent yields, solvent-free conditions and stability and reusability of the catalyst.     

Synthesis of Bis(indolyl) Methanes in Catalyst- and Solvent-Free Reaction

Efficient synthesis of bis(indolyl) methanes by the reaction of indoles with various carbonyl compounds in the absence of catalyst and solvent afforded the corresponding bis(indolyl) methanes in excellent yields.