一个简单、环境友好的硅胶固载硫酸催化Biginelli反应体系(英文)

A protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and-thiones was developed by means of a three-component condensation of an aldehyde,a β-dicarbonyl compound,and urea or thiourea in acetic acid catalyzed by silica-bonded S-sulfonic acid.Compared to the classical Biginelli reaction conditions,this new protocol has the advantages of consistently excellent yields and short reaction times.After the reaction,the catalyst could be recovered easily and reused with little change in its activity.     

Efficient Synthesis of Symmetrical Bisamides from Aldehydes and Amides Catalyzed by Silica-Bonded S-Sulfonic Acid Nanoparticles

Silica-bonded S-sulfonic acid nanoparticles (SBSSANPs) were easily synthesized from silica nanoparticles and showed to be an efficient catalyst in the synthesis the symmetrical N,N′-alkylidene bisamides. Reaction of aldehydes and amides in the presence of the catalyst afforded the corresponding bisamides in good to excellent yields. The extensive range of substrates suggests general applicability of the method. Reusability of the catalyst, simple workup procedure, and short reaction times are other advantages of this protocol.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications ^® to view the free supplemental file.     

Silica-bonded S-Sulfonic Acid: A Recyclable Catalyst for the Synthesis of Trisubstituted Imidazoles under Solvent-free Conditions

Trisubstituted imidazoles have been synthesized in high yields in the presence of silica‐bonded S‐sulfonic acid as a catalyst. The reaction was carried out at 130°C under solvent‐free conditions. The reaction work‐up is simple and the catalyst is easily separated from the products by filtration.     

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 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.     

Glycerin and CeCl3·7H2O: a new and efficient recyclable medium for the synthesis of bis(indolyl)methanes

Glycerin and CeCl₃·7H₂O were successfully used in recyclable catalytic system for the synthesis of several bis(indolyl)methanes in good to excellent yields through the reaction of indoles with aldehydes. The method is applicable to aliphatic and aromatic aldehydes, and the mixture of glycerin and CeCl₃·7H₂O can be reused up to five times without special treatment and with comparable yields.     

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。     

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.     

Synthesis of bis(indolyl)methanes using silica gel as an efficient and recyclable surface

Here we describe a simple, clean, and efficient solvent-free protocol for the synthesis of bis(indolyl)methanes promoted by silica gel. The products were obtained in good to excellent yields through the reaction of indoles with cyclohexanone and a range of aldehydes. The silica gel was easily recovered and utilized for further reactions without loss of activity.     

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.     

Utilization of flow chemistry in catalysis: New avenues for the selective synthesis of Bis(indolyl)methanes

Flow chemistry enables the preparation of bis(indolyl)methanes from various indoles and structurally divergent aldehydes using Sc(OTf)₃ catalysis. The reaction is regioselective for C-3 functionalization of the indoles, occurring over short reaction times allowing for rapid investigation of scope with straightforward work up facilitating product isolation.     

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.     

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.     

硅胶键合的N-丙基三亚乙基四胺氨基磺酸作为可回收固体酸催化剂催化合成2-氨基-4,6-二芳基烟腈(英文)

A simple and efficient procedure for the preparation of silica-bound N-propyl triethylenetetramine sulfamic acid(SBPTETSA) by the reaction of silica-bound N-propyl triethylenetetramine(SBPTET) with chlorosulfonic acid in chloroform is described.Silica-bound N-propyl triethylenetetramine sulfamic acid was employed as a recyclable catalyst for the synthesis of 2-amino-4,6-diarylnicotinonitriles from the multi-component reaction of an acetophenone derivative,an aromatic aldehyde,malononitrile,and ammonium acetate under solvent-free conditions at 100 °C.The heterogeneous catalyst was recycled for five consecutive runs in the optimized multi-component reaction of 4-chloroacetophenone,4-chloroenzaldehyde,malononitrile,and ammonium acetate without significant loses to its catalytic activity.     

高效可回收聚(4-乙烯基吡啶)高氯酸催化剂用于合成双香豆素和双吲哚(英文)

Poly(4-vinylpyridinium) perchlorate has been used as an efficient solid acid catalyst for the synthesis of 3,3'-(arylmethylene)bis(4-hydroxycoumarins) and bis(indolyl)methanes, with the products being formed in excellent yields over very short reaction times under mild and environmentally friendly conditions. This catalyst can be reused several times without any appreciable loss in its activity.     

Facile synthesis of bis(indolyl)methanes using catalytic amount of iodine at room temperature under solvent-free conditions

Efficient electrophilic substitution reactions of indoles with various aromatic aldehydes were carried out using a catalytic amount of I₂ under solvent-free conditions to afford the corresponding bis(indolyl)methanes in excellent yields.     

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.     

Water and fluorinated alcohol mediated/promoted tandem insertion/aerobic oxidation/bisindolylation under metal-free conditions: Easy access to bis(indolyl)methanes

A green tandem reaction, including insertion/aerobic oxidation/bisindolylation, starting from indoles and diazo compounds has been developed. The combination of water and fluorinated alcohol plays dual roles as solvent and promoter in this chemical transformation. Molecular oxygen in the air acts as an oxidant. 3,3′-Bis(indolyl)methanes with quaternary carbon were produced under metal-free conditions. No any catalyst and additive were required. N₂ and water were released as sole by-products. Absence of water and fluorinated alcohol resulted in Wolff rearrangement product.     

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.     

((3-(3-硅胶丙基)硫基)丙基)硫酸酯作为可回收催化剂用于合成4,4'-芳亚甲基-双(1H-吡唑-5-醇)(英文)

Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone. This condensation reaction was performed in ethanol under refluxing conditions giving 4,4'-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields. The heterogeneous catalyst was recycled and used in eleven runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without losing catalytic activity.