Amberlyst-15? in PEG: A novel catalytic system for the facile and efficient one-pot synthesis of benzothiazolo-[2,3-b]-quinazolinone derivatives

A simple and convenient approach for the synthesis of tetraheterocyclic benzothiazolo-[2,3-b]-quinazolin-1-ones has been developed utilizing the MCR methodology, which involves the condensation of 2-aminobenzothiazole, cyclic-diketones and various aldehydes using Amberlyst-15 in PEG 400 as an environmentally benign and reusable catalyst system. Environmental benignity, recyclability, cost-effectiveness, easy workup and excellent yields are the major attributes of this one-pot procedure.     

Iodine as a mild and efficient catalyst for the diastereoselective synthesis of δ-silyloxy-γ-lactones

Aldehydes undergo smooth nucleophilic addition with 2-trimethylsilyloxyfuran in the presence of 10 mol % of iodine under mild and neutral conditions to produce the corresponding δ-silyloxy-α,β-unsaturated-γ-lactones in high yields and with moderate diastereoselectivity. ortho-Substituted benzaldehydes afford the syn-isomer predominantly. The use of iodine makes this procedure quite simple, more convenient and cost-effective.     

Microwave assisted efficient synthesis of β-keto-sulfones in aqueous medium

Abstract

An efficient synthesis of β-keto-sulfones is described. The reaction of α-haloketones with sodium alkyl/aryl sulphinates in aqueous medium under microwave irradiation afforded the corresponding β-keto-sulfones in excellent yields.     

Silica-supported LiHSO4 as a highly efficient, heterogeneous and reusable catalytic system for the solvent-free synthesis of β-enaminones and β-enamino esters

A highly efficient, simple and green procedure for the synthesis of β-enaminones and β-enamino esters is described. The reaction of aromatic and aliphatic amines with β-dicarbonyl compounds using catalytic amount of silica-supported LiHSO₄ (LiHSO₄/SiO₂) under solvent-free conditions at 80 °C affords the title compounds in high to excellent yields and in short reaction times.     

Ruthenium(Ⅲ) chloride as an efficient catalyst for the synthesis of perimidine derivatives under mild conditions

Various biologically important perimidine derivatives have been synthesized efficiently from various ketones and naphthalene1,8-diamine by using a catalytic amount of RuC13 (1 mol%). This method is a very simple and high yielding reaction for the synthesis of perimidine derivatives.     

BF3·nano SiO2 as a catalytic system for one-pot green synthesis of pyrophthalone derivatives under microwave conditions: 1st Nano Update

The expeditious and solvent-free approach that involves the exposure of neat reactants to microwave (MW) irradiation in conjunction with the use of supported catalysts was described. A simple one-pot and green reaction of methylpyridine derivatives and phthalic anhydride derivatives on the surface of a nano silica gel impregnated with BF₃ as solid supported catalysts under microwave irradiation without any solvent according to green chemistry was developed. The salient features of these high yield protocols are the enhanced reaction rates, greater selectivity and the experimental ease of manipulation.     

Trifluoroethanol as a metal-free, homogeneous and recyclable medium for the efficient one-pot synthesis of α-amino nitriles and α-amino phosphonates

Trifluoroethanol is found to be an efficient and recyclable medium in promoting one-pot, three-component coupling reactions of aldehydes or ketones, amines and trimethylsilyl cyanide or trimethyl phosphite to afford the corresponding α-amino nitriles or α-amino phosphonates in high yields. This protocol does not require the use of an acid or base catalyst.     

Poly(4-vinylpyridine)：As a green, efficient and commercial available basic catalyst for the synthesis of chromene derivatives

Poly(4-vinylpyridine) is reported as a green,commercial available and efficient basic recyclable catalyst for the synthesis of chromene derivatives.This catalyst can be easily recovered by simple filtration and recycled up to 5 consecutive runs without any loss of its efficiency.     

Design and synthesis of cholesterol-bonded fullerene and porphyrin derivatives for the preparation of a self-assembled donor–acceptor system

The cholesterol-bonded fullerene and porphyrin derivatives were synthesised and characterised. Donor–acceptor thin films were self-assembled through the interaction between cyclodextrin and the cholesterol groups on porphyrin and fullerene derivatives. These uniform films were characterised by ultraviolet–visible and fluorescence spectroscopies. Scanning electron microscopy indicated that the self-assembled film had a chain-like fibre structure with the chains having a diameter of about 50 nm. The intermolecular interaction between chromophores and the formation of complex based on cholesterol and cyclodextrin were proven by the quenching of fluorescence due to the charge transfer from porphyrin moieties to the fullerene units.     

Superparamagnetic Fe3O4@Alginate supported L-arginine as a powerful hybrid inorganic–organic nanocatalyst for the one-pot synthesis of pyrazole derivatives

Hybrid inorganic–organic material Fe₃O₄@Alg@CPTMS@Arg, was prepared by the layer-by-layer techniques through grafting l-arginine (l-arg) to Fe₃O₄@Alg using 3-chloropropyltrimethoxysilane (CPTMS) as a linker. Fe₃O₄@Alg was prepared by in situ co-precipitation of iron (iii) and iron (ii) chloride in the presence alginate (Alg). The hybrid inorganic–organic material was characterized employing various techniques such as Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The as-prepared Fe₃O₄@Alg@CPTMS@Arg nanoparticles mediated the synthesis of pyrazole derivatives with via one-pot reaction between phenylhydrazine, malononitrile, and various aromatic aldehydes under reflux in ethanol. Recycled catalyst exhibited comparable efficacy after seven cycles. The high catalytic activity, excellent yields, as well as the recyclability of the hybrid nanomaterials with quantitative efficiency, are factors that render this environmentally benign procedure appealing.     

Use of organomagnesium compounds for the synthesis of organic derivatives of group II–V elements in a nonethereal medium

Summary For the primary alkyl halides (R=from C₂H₅ to n-C₉H₁₉; halogen=C1, Br, and I) and the simplest aryl halides (R=C₆H₅ and p-CH₃C₆H₄) it was shown that the organomagnesium synthesis in absence of catalysts for the Grignard reaction can be applied with success to the preparation of heteroorganic compounds of elements of Groups II–IV (mercury, boron, aluminum, silicon, germanium, tin, phosphorus, arsenic, antimony).     

NiSO4·6H2O as a new,efficient, and reusable catalyst for the α-aminophosphonates synthesis under mild and eco-friendly conditions

Research on Chemical Intermediates - Nickel (II) sulfate hexahydrate is used for the first time as an efficient catalyst for the one-pot synthesis of α-aminophosphonates by three-component...     

Lewis acid–catalyzed green synthesis and biological studies of pyrrolo[3,4-c]pyrazoles in aqueous medium

An environmentally benign approach in aqueous medium by means of Lewis acid catalyst affords a wide spectrum of pyrazoline derivatives in satisfactory yields. [3+2] cycloaddition reactions of substituted azomethine-N-imines to maleimide in aqueous medium at relatively high concentrations of Lewis acid catalyst have emerged as an environment friendly alternative to conventional solvents. Promising catalytic activity has been revealed by Lewis acid like Cu (NO₃)₂ in aqueous medium. The obvious features of this synthetic protocol were short reaction time, high efficiency, less hazardous synthesis by benign solvent, catalysis, modest workup, and a clean reaction methodology.     

Uniform copper nanoparticles as an inexpensive and efficient catalyst for synthesis of novel β-carbonyl-1, 2, 3-triazoles in water medium

Copper nanoparticles as an efficient, inexpensive catalyst were prepared via ball milling for synthesis of β-carbonyl 1, 2, 3-triazoles from azido alcohol by click reaction in water. An extensive range of raw materials such as sodium azide, phenacyl bromide, epichlorohydrin, and terminal alkynes were used. Complete reduction of CuO in presence of NaBH₄ was done via ball milling with a ball-to-powder weight ratio of 50:1 under air atmosphere at room temperature. The final copper nanoparticles (Cu NPs) were characterized by SEM, EDX, XRD and FT-IR. The Cu NPs catalyzed one-pot three component synthesis of β-carbonyl 1, 2, 3-triazoles at room temperature with short reaction time and high product yields. The catalyst could be easily recovered and reused in several successive runs.

     

A facile electrochemical synthesis of caffeic acid derivatives in the presence of acetylacetone or methyl acetoacetate in aqueous medium

The anodic oxidation of caffeic acid in the presence of acetylacetone or methyl acetoacetate in aqueous solution has been studied by cyclic voltammetry and controlled-potential electrolysis techniques. The result showed that caffeic acid was oxidized to the corresponding o-benzoquinone, which underwent further Michael-addition with acetylacetone or methyl acetoacetate to produce caffeic acid derivative 3,4-dihydroxy-6-(1-acetylacetone)-yl cinnamic acid 4a or 3,4-dihydroxy-6-(1-acetyl-methylacetate)-yl cinnamic acid 4b.     

Heterocyclization of β,γ-dichloro ketones as a method for the synthesis of furan derivatives

Dichloro ketones obtained from acyl chlorides and allyl or -methylallyl chloride undergo spontaneous cyclization to give 2-alkyl- and 2,4-dialkylfurans when they are heated; the intermediates in the case of 2,3-dichloropropene split out a molecule of hydrogen chloride to give 3,4-dichloro-2-butenones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 313–319, March, 1992.     

γ-Valerolactone (GVL) as a green and efficient dipolar aprotic reaction medium

The great challenge for modern research is to define the most efficient tools to make more sustainable the industrial production and manufacturing. Among the different aspects that require attention the replacement of toxic and/or non-renewable solvents it is certainly playing a crucial role. Dealing with widely used dipolar aprotic solvents, among the different alternatives proposed in the literature γ-valerolactone (GVL) plays a pivotal role covering different application area. In this contribution, the benefits derived from the use of GVL as a circular, safe, biomass-derived reaction medium are highlighted covering most recent publications (2021). The presentation has been divided into three major sections: (i) biomass valorization, (ii) materials synthesis, manufacturing and recycle and (iii) new synthetic methodologies.