Three-component Method Research Articles

Convenient DABCO-catalyzed one-pot synthesis of multi-substituted pyrano[2,3-c]pyrazole dicarboxylates

We developed an efficient and simple one-pot synthesis of functionalized multi-substituted 2,4-dihydro-pyrano[2,3-c]pyrazole dicarboxylates from β-ketoesters, hydrazine, dimethyl acetylenedicarboxylate and malononitrile in EtOH. This four-component one-pot reaction carried out in the presence of DABCO catalyst showed advantages over a one-pot three-component method in its simple procedure, high yield and low toxicity.

An Efficient Pd/Al(OH)3 Nanoparticle Catalyst for Suzuki Coupling Reactions of Aryl Halides

A high-performance palladium-based Pd/Al(OH) 3 catalyst has been prepared by the one-pot three-component method. It was found that this ‘ligandless’ Pd/Al(OH) 3 catalyst showed remarkable reactivity and gave excellent yields (up to 99%) towards the condensation of aryl bromides with various arylboronic acids under mild conditions, and afforded good yields of the coupling products (up to 97%) with most aryl chlorides in two different catalytic systems. Furthermore, this catalyst could be easily recovered through filtration and reused for 8 cycles without significant loss of the yield.

One-pot, three-component, green procedure for efficient synthesis of allomaltol derivatives

We report an efficient, mild, one-pot, three-component method, catalyzed by Et3N in the ionic liquid [bmim+][BF4 −], for synthesis of 2-[(aryl)-(3-hydroxy-6-methyl-4-oxo-4H-pyran-2-yl)methyl]indan-1,3-diones from aromatic aldehydes, 1,3-indanedione, and 5-hydroxy-2-methyl-4H-pyran-4-one. The method has the advantages of high yields, mild reaction conditions, convenient operation, and environmental friendliness.

An efficient one-pot three-component synthesis and antimicrobial evaluation of tetra substituted thiophene derivatives

Abstract A convenient one-pot three-component method for the preparation of tetra-substituted thiophene derivatives has been developed. Reaction of acetyl acetone 1 , phenyl isothiocynate 2 and 2-chloromethyl derivatives 3a – 3c in the presence of potassium carbonate afforded the target compounds, namely ethyl 2-(4-acetyl-3-methyl-5-(phenylamino)thiophen-2-yl)-2-oxoacetate derivatives 4a – 4e , ethyl 3-(4-acetyl-3-methyl-5-(phenylamino)thiophen-2-yl)-3-oxopropanoate derivatives 4f – 4i , di((4-acetyl-3-methyl-5-phenylamino)thiophen-2-yl)ketone derivatives 4j – 4n in reasonable overall yields. The synthesized compounds were screened for antimicrobial activity. The detailed synthesis, spectroscopic data and antimicrobial activities of synthesized compounds were reported.

A Direct Copper-Promoted Three-Component Entry to Trifluoromethylketoximes

A new copper-promoted three-component method for constructing ketoximes has been developed. This transformation can be achieved using indoles/pyrroles with the in situ generated 2,2,2-trifluorodiazoethane and nitrite species under mild conditions, thus offering a direct pathway to (E)-3-indolyl/2-pyrrolyl trifluoromethylketoximes.

ChemInform Abstract: A One‐Pot, Three‐Component, Microwave‐Promoted Synthesis of 2‐Amino‐Substituted 7‐Amino‐1,2,4‐triazolo[1,5‐a][1,3,5]triazines.

A new, efficient, catalyst-free, one-pot, three-component method for the synthesis of 2-amino-substituted 7-amino-1,2,4-triazolo[1,5-a][1,3,5]triazines using 3,5-diamino-1,2,4-triazoles, cyanamide, and triethyl orthoformate is developed. The reaction proceeds smoothly under microwave-assisted heating. Advantages of the method include using easily available reagents, short reaction times, and operational simplicity.

Modified Three-Component Decomposition Method for Polarimetric SAR Data

In this letter, a modified three-component model-based decomposition method is proposed to solve the problem of instability present in the Freeman decomposition method. We incorporate the similarity parameter and introduce a new constraint that describes the relationship between the powers of scattering components. The proposed method minimizes a continuous objective function under a set of constraints, which results in the stability of the decomposition method. Furthermore, a fast algorithm for solving the optimization problem is developed to accelerate computation. We demonstrate the stability of the proposed decomposition method by using the E-SAR polarimetric data acquired over the Oberpfaffenhofen area.

An efficient and facile regioselective synthesis of new substituted (E)-1-(3-aryl-7,8-dihydrocinnoline-5(6H)-ylidene)hydrazines and (1E,2E)-1,2-bis(3-aryl-7,8-dihydrocinnoline-5(6H)-ylidene)hydrazines

A study concerning the new substituted cinnoline synthesis is described. The use of a one-pot three-component method allows a simple regioselective and efficient synthesis of cinnoline derivatives via reaction of arylglyoxals with 1,3-cyclohexanedione and dimedone in the presence of hydrazine hydrate.

Highlighting pros and cons of abundance estimation using passive acoustic data: monitoring fin whales (Balaenoptera physalus) off the southern Portuguese coast using seismometers

Monitoring marine mammals using passive acoustic sensors is increasingly popular. Generating abundance estimates from acoustic data would be extremely useful for marine environment stakeholders. To achieve accurate abundance estimates, there are three broad areas to consider: (1) survey design, (2) data collection and processing, and (3) data analysis. Here, we use an analysis of fin whale (Balaenoptera physalus) calls recorded on ocean bottom seismometers (OBSs) to discuss the main advantages, disadvantages and considerations of abundance estimation using acoustic data. The OBS array was deployed for one year (2007–2008) and demonstrates how an opportunistic dataset can meet survey design requirements. Ranges to detected calls (detected with a matched filter) were estimated using the seismological three-component method. Point transect sampling, an abundance estimation method, was then used to estimate average call density. Animal density or abundance could not be estimated because the appropriate average calling rate was unknown. Finally, spatiotemporal patterns of call density were modeled. This dataset has also allowed new methods development—a method that estimates abundance as a function of total energy in a species’ frequency band has been developed. In summary, abundance estimation using acoustic data is possible but challenging, and improved knowledge of vocal behavior is essential.

A one-pot, three-component, microwave-promoted synthesis of 2-amino-substituted 7-amino-1,2,4-triazolo[1,5-a][1,3,5]triazines

A new, efficient, catalyst-free, one-pot, three-component method for the synthesis of 2-amino-substituted 7-amino-1,2,4-triazolo[1,5-a][1,3,5]triazines using 3,5-diamino-1,2,4-triazoles, cyanamide, and triethyl orthoformate is developed. The reaction proceeds smoothly under microwave-assisted heating. Advantages of the method include using easily available reagents, short reaction times, and operational simplicity.

A facile solvent-free one-pot three-component method for the synthesis of 2-amino-4H-pyrans and tetrahydro-4H-chromenes at ambient temperature

2-Amino-4H-pyrans and tetrahydro-4H-chromenes were readily prepared via a one-pot, three-component reaction of an aldehyde, malononitrile, and ethyl acetoacetate or 5,5-dimethyl-1,3-cyclohexanedione in the presence of anhydrous piperazine as an efficient and recyclable organocatalyst under solvent-free ball-milling at ambient temperature, with high to quantitative yields.

Click Synthesis of 5-Substituted 1H-Tetrazoles from Aldehydes, Hydroxyl­amine, and [bmim]N3 via One-Pot, Three-Component Reaction

An easy and efficient one-pot, three-component method for the synthesis of 5-substituted 1H-tetrazole derivatives, via the reaction of aldehydes, hydroxylamine, and [bmim]N3, is reported.

Automated three-component synthesis of a library of γ-lactams

A three-component method for the synthesis of γ-lactams from commercially available maleimides, aldehydes, and amines was adapted to parallel library synthesis. Improvements to the chemistry over previous efforts include the optimization of the method to a one-pot process, the management of by-products and excess reagents, the development of an automated parallel sequence, and the adaption of the method to permit the preparation of enantiomerically enriched products. These efforts culminated in the preparation of a library of 169 γ-lactams.

One-Pot, Two-Step Conversion of Aldehydes to Phosphonyl- and Sulfonylpyrazoles Using Bestmann–Ohira Reagent

A one-pot, two-step, three-component method for the conversion of commercially available aldehydes to phosphonylpyrazoles has been developed, demonstrating, for the first time, the dual reactivity of the Bestmann-Ohira reagent (BOR) in a single-pot transformation. This method, extended to the synthesis of sulfonylpyrazoles by employing BOR in the first step and a diazomethyl sulfone in the second step, is complementary, with regard to regioselectivity, to the previous methods for the synthesis of such functionalized pyrazoles.

Ionic Liquid Promoted Efficient Three-Component Synthesis of 2-Thioxo-2H-Thiopyrans

An efficient one-pot three-component method for the synthesis of a variety of 2-thioxo-2H-thiopyrans has been described. Fairly good yields are obtained by cyclization reactions of arylidenemalononitriles, derived in situ from ketones and malononitrile, with carbon disulfide in the presence of a base in the ionic liquid 1-butyl-3-methylimidazolium bromide as reaction medium.[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Selected Data.]GRAPHICAL ABSTRACT

KAl(SO4)2·12H2O (Alum) Catalyzed One‐Pot Three‐Component Synthesis of 2‐Alkyl and 2‐Aryl‐4(3H)‐quinazolinone under Microwave Irradiation and Solvent Free Conditions

AbstractTwenty 2,3‐disubstituted‐4(3H)‐quinazolinones were synthesed by one‐pot three‐component method with isatoic anhydride, orthoesters and amines as raw materials in the presence of KAl(SO4)2·12H2O (Alum) under microwave irradiation and solvent‐free conditions. 6‐Bromo‐2‐propyl‐3‐p‐tolylquinazolin‐4(3H)‐one (4m), 6‐bromo‐2‐methyl‐3‐phenethylquinazolin‐4(3H)‐one (4n) and 6‐bromo‐2‐ethyl‐3‐phenethylquinazolin‐4(3H)‐one (4o) were characterized by IR, 1H NMR, 13C NMR and elemental analysis.

ChemInform Abstract: Three‐Component Synthesis of 2‐Oxoindolin‐3‐ylphosphonates

Abstractand related acenaphthylenyl phosphonates (VI) under catalyst‐ and solvent‐free conditions

A simple and catalyst-free three-component method for the synthesis of spiro[indenopyrazolopyridine indoline]diones and spiro[indenopyridopyrimidine indoline]triones

Abstract An efficient, simple and catalyst-free synthesis of spiro[indeno[1,2-b]pyrazolo[4,3-e]pyridine indoline]diones and spiro[acenaphthylene-indeno[1,2-b]pyrazolo[4,3-e]pyridine]diones by the three-component reaction of 1,3-indandione, pyrazol-5-amines and isatins or acenaphthylene-1,2-dione in refluxing ethanol is reported. Reaction of 2,6-diaminopyrimidin-4(3H)-one with 1,3-indandione and isatins resulted in the formation of 1H-spiro[indeno[1,2-b]pyrido[2,3-d]pyrimidine-5,3′-indoline]-2′,4,6(11H)-triones.

ChemInform Abstract: One‐Pot, Three‐Component Synthesis of 3‐(5‐Amino‐1H‐pyrazol‐4‐yl)‐3‐ (2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐enyl)indolin‐2‐ones.

A clean, efficient, one-pot, three-component method for the synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-one derivatives by condensation reaction of dimedone, 1H-pyrazol-5-amines, and isatins in aqueous media is reported.

One-Pot, Three-Component Synthesis of 3-(5-Amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-ones

A clean, efficient, one-pot, three-component method for the synthesis of 3-(5-amino-1H-pyrazol-4-yl)-3-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)indolin-2-one derivatives by condensation reaction of dimedone, 1H-pyrazol-5-amines, and isatins in aqueous media is reported.