SiO2–OSO3H Nanoparticles: An Efficient, Versatile and New Reagent for the One-Pot Synthesis of 2-Amino-8-Oxo-4,8-Dihydropyrano[3,2-b]Pyran-3-Carbonitrile Derivatives in Water, a Green Protocol:
01 Jan 2014-Journal of Chemical Research-s (SAGE PublicationsSage UK: London, England)-Vol. 38, Iss: 1, pp 54-57
TL;DR: In a one-pot three-component reaction, an aromatic or aliphatic aldehyde, malononitrile and 5-hydroxy-2-hydroxymethyl-4H-pyran-4-one were condensed for the synthesis of 2-amino-8-oxo-4,8-dihydropyr...
Abstract: In a one-pot three-component reaction, an aromatic or aliphatic aldehyde, malononitrile and 5-hydroxy-2-hydroxymethyl-4H-pyran-4-one were condensed for the synthesis of 2-amino-8-oxo-4,8-dihydropyr...
Citations
More filters
TL;DR: In this paper, an atom-efficient, three-component synthetic methodology has been developed for the preparation of biologically important pyrano[2,3-d]pyrimidines using nano-sawdust-OSO3H as a new catalyst.
Abstract: An atom-efficient, three-component synthetic methodology has been developed for the preparation of biologically important pyrano[2,3-d]pyrimidines using nano-sawdust-OSO3H as a new catalyst. The reaction involves the use of barbituric acid or thiobarbituric acid, malononitrile and aldehydes. A wide range of aldehydes is compatible in this reaction, producing excellent yields in short time. The morphology of nanocatalyst (nano-sawdust-OSO3H) was observed using a scanning electron microscopy (SEM). The decomposition steps and thermal stability of the catalyst were investigated by thermal analysis techniques (TGA/DTG). The sawdust-OSO3H surface was studied by energy dispersive X-ray spectroscopy (EDX) method to find out the chemical composition. Also, the vibrational spectrum analysis (FT-IR) of the catalyst has been performed.
60 citations
TL;DR: Developments made since 2010 in the utilization of multi-component reactions as green efficient methodologies for the synthesis of polysubstituted pyran, thiopyrans, pyridines, and pyrazoles are reviewed and the mechanisms of these processes are discussed.
Abstract: Developments made since 2010 in the utilization of multi-component reactions as green efficient methodologies for the synthesis of polysubstituted pyrans, thiopyrans, pyridines, and pyrazoles are reviewed and the mechanisms of these processes are discussed. Reference is made to classical older synthetic methods developed earlier in our laboratories.
29 citations
TL;DR: In this review, ultrasonic irradiation provides lower cost, excellent yields, greater purity, and simple workups as compared to lower yields, longer reaction times, lesser purity and in the conventional methods.
Abstract: In this review, we tried to underscore the synthesis of the heterocyclic compounds under assisted ultrasonic irradiation. The ultrasonic irradiation has been applied for medicinal chemistry and drug discovery process since it dramatically reduces reaction times, from days or hours to minutes. Also, ultrasonic irradiation provides lower cost, excellent yields, greater purity, and simple workups as compared to lower yields, longer reaction times, lesser purity and in the conventional methods. In this review, we have compared synthesis of the heterocyclic compounds under ultrasonic irradiation with other methods.
28 citations
TL;DR: In this article, an ionic liquid-based s-triazine-immobilized silica-coated Fe3O4 magnetic nanoparticles were used for one-pot three-component synthesis of 4,8-dihydropyrano[3,2-b]pyran derivatives in excellent yields.
Abstract: We have described a new method to heterogenize s-triazine catalyst by easy preparation of ionic liquid-based s-triazine-immobilized silica-coated Fe3O4 magnetic nanoparticles [Fe3O4@SiO2-s-triazinium chloride]. The structure of the newly prepared nanoparticles was characterized by Fourier transform infrared, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray method, vibrating sample magnetometery and thermo-gravimetric analysis. These nanoparticles were identified as an efficient catalyst for one-pot three-component synthesis of 4,8-dihydropyrano[3,2-b]pyran derivatives in excellent yields. The catalyst was easily separated by magnetic decantation, and the recovered nanoparticles were reused for four fresh runs without any significant loss of catalytic activity. The synthesized dihydropyrano[3,2-b]pyrans were evaluated for their antioxidant and antifungal activities and found they are relatively active.
21 citations
TL;DR: In this article, a facile, green, and efficient method has been developed for the synthesis of biologically important pyrano [4,3-b] pyrans in the presence of nanocellulose-OSO3H as a new solid acid catalyst.
Abstract: A facile, green, and efficient method has been developed for the synthesis of biologically important pyrano [4,3-b] pyrans in the presence of nano-cellulose-OSO3H as a new solid acid catalyst. The reaction involves the use of 4-hydroxy-6-methyl-2H-pyran-2-one, malononitrile, and aldehydes. A wide range of aldehydes is compatible in this reaction, producing excellent yields in short time. The morphology of nano-catalyst (nano-cellulose-OSO3H) was observed using a scanning electron microscopy (SEM). The cellulose-OSO3H surface was studied by the energy dispersive X-ray spectroscopy (EDX) method to find out the chemical composition. The decomposition steps and thermal stability of the catalyst were investigated by thermal analysis techniques (TGA/DTG). In addition, the vibrational spectrum analysis (FT-IR) and X-ray diffractogram (XRD) of the catalyst have been performed.
19 citations
References
More filters
TL;DR: Reaction of R,â-Unsaturated Carbonyl Compounds 3127: Reaction of R-UnSaturated Carbonies 3127 7.1.6.
Abstract: 4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylation 3121 6.1.6. Alkylation 3121 6.1.7. Reformatsky-Type Reaction 3122 6.1.8. Direct Aldol Reaction 3122 6.1.9. Mukaiyama Aldol Reaction 3124 6.1.10. Hydrogen Cyanide Addition 3125 6.2. Pinacol Coupling 3126 6.3. Wittig Reactions 3126 7. Reaction of R,â-Unsaturated Carbonyl Compounds 3127
2,031 citations
1,477 citations
TL;DR: New types of Lewis acids as water-compatible catalysts have been developed and catalytic asymmetric aldol reactions in such media have been attained, which will contribute to reducing the use of harmful organic solvents and to develop efficient catalytic systems which cannot be realized in conventional organicsolvents.
Abstract: New types of Lewis acids as water-compatible catalysts have been developed. Various metal salts were found to work as Lewis acid catalysts in aqueous media, and catalytic asymmetric aldol reactions in such media have been attained. Furthermore, Lewis acid-surfactant combined catalysts, which can be used for reactions in water without using any organic cosolvents, have been also developed. These investigations will contribute to reducing the use of harmful organic solvents and to develop efficient catalytic systems which cannot be realized in conventional organic solvents.
679 citations
TL;DR: Fifteen novel non-peptide HIV-1 protease inhibitors were identified by flexible 3D database pharmacophore searching of the NCI DIS3D database by using X-ray determined structures of protease/inhibitor complexes.
Abstract: Fifteen novel non-peptide HIV-1 protease inhibitors were identified by flexible 3D database pharmacophore searching of the NCI DIS 3D database. The pharmacophore query used in the search was derived directly from the X-ray determined structures of protease/inhibitor complexes. These 15 inhibitors, belonging to nine different chemical classes, are promising leads for further development. The two best inhibitors found, NSC 32180, a "dimer" of 4-hydroxycoumarin, and NSC 117027, a "tetramer" of 2-hydroxy quinone, had ID50 values of 0.32 and 0.75 microM for HIV-1 protease inhibition, respectively, and two other inhibitors had ID50 values close to 1 microM. Among the potent inhibitors, NSC 158393 not only demonstrated activity against HIV-1 protease (ID50 1.7 microM) but also exhibited promising antiviral activity in HIV-1-infected CEM-SS cells (EC50 = 11.5 microM). Validation of the pharmacophore used in the search was accomplished by conformational analysis. The binding modes of the most potent inhibitor found in our studies, NSC 32180, were predicted employing docking and molecular dynamics techniques.
115 citations
TL;DR: In this paper, the authors used experimentally measured nucleation and ionic strength transients to confirm that an aggregation model can predict the particle growth profiles of Stober systems for a range of conditions.
111 citations