Y.V.D. Nageswar

Multi-component supramolecular synthesis of spirooxindoles catalyzed by β-cyclodextrin in water

A neutral and efficient one-pot three-component aqueous-phase synthesis is developed for various spirooxindole derivatives from isatin, malononitrile, and 1,3-dicarbonyl compounds in high yields by...

Recyclable Ru/C catalyzed oxidative cyanation of tertiary amines with TBHP

The recyclable Ru/C catalyzed oxidative α-cyanation of tertiary amines with ethyl cyanoformate by using TBHP as an oxidant under ambient conditions has been developed. Utilizing this protocol, α-aminonitrile derivatives were synthesized in good to excellent yields with high selectivity. The cyanide source (ethyl cyanoformate) employed herein was relatively cheap and less toxic, which would be beneficial. The catalyst was also inexpensive and commercially available as well as recyclable up to four cycles, without significant loss of its catalytic activity.

Recent Developments in the Synthesis of Quinoxaline Derivatives by Green Synthetic Approaches

Introduction .....................................................................................2 I. Using Recyclable Catalysts................................................................3 A. Acid-catalyzed Reactions.......................................................................... 3 1. Sulfamic Acid-MeOH................................................................................ 3 2. Silica-supported Perchloric Acid................................................................ 4 3. Silica-bonded S-Sulfonic Acid ................................................................... 5 4. Iron-exchanged Molybdophosphoric Acid................................................... 5 B. Metal/metal Salt-catalyzed Reactions........................................................ 6 1. Ni-nano Particles ..................................................................................... 6 2. CuO Nano Particles.................................................................................. 7 3. Manganese Octahedral Molecular Sieves ................................................... 8 4. Silica-supported Antimony (III) Chloride.................................................... 8 5. ZnO-β Zeolite .......................................................................................... 9 6. PdCl2/Cu2Cl2 in PEG..............................................................................10 7. Ruthenium-on-charcoal ...........................................................................10 8. Zirconium (IV) Oxide Chloride Octahydrate ..............................................11 C. Other Recyclable Catalysts ......................................................................12 1. 1-(n-Butyl)imidazolium Tetrafluoroborate..................................................12 2. β-Cyclodextrin........................................................................................12 3. Hypervalent Iodine(III) Sulfonate-PEG 400...............................................13 4. Amberlyst-15 ..........................................................................................14 II. Using Microwave Energy ................................................................ 14 III. In Aqueous Media........................................................................... 19 1. Using Ceric(IV) Ammonium Nitrate ..........................................................19 2. Using Trimethylsilyl Chloride...................................................................20 3. Using N-Bromosuccinimide......................................................................21 IV. At Room Temperature .................................................................... 22 V. Conclusion...................................................................................... 25 References ...................................................................................... 25

Synthesis of N-Substituted Pyrroles Under Catalyst- and Solvent-Free Conditions

Abstract N-Substituted pyrroles were synthesized under neat conditions by the reaction of aromatic amines with 2, 5-dimethoxytetrahydrofuran in excellent yields. GRAPHICAL ABSTRACT

Synthesis of β-hydroxy-1,4-disubstituted-1,2,3-triazoles catalyzed by copper ferrite nanoparticles in tap water using click chemistry

A novel one pot synthesis of β-hydroxy-1,4-disubstituted-1,2,3-triazoles has been developed by using CuFe2O4 magnetic nanoparticles. This methodology involves additive free, easily recyclable catalyst in water medium and avoids the handling of organic azides as they are generated in situ.

Synthesis of Thiazoles and Aminothiazoles from β‐Keto Tosylates under Supramolecular Catalysis in the Presence of β‐Cyclodextrin in Water

Abstract This is the first report on the supramolecular synthesis of thiazoles/aminothiazoles from β‐keto tosylates and thioamide/thiourea in water in the presence of β‐cyclodextrin in impressive yields. Formation of inclusion complexes was explained from 1H NMR studies.

Facile Deprotection of 1,3‐Oxathiolanes to Carbonyl Compounds with O‐Iodoxy Benzoic Acid (IBX) in the Presence of β‐Cyclodextrin in Water

Abstract 1,3‐Oxathiolanes are smoothly deprotected to carbonyl compounds by IBX at room temperature with β‐cyclodextrin as a catalyst and water as solvent. IICT Communication No. 060424.

Ru/C: a simple heterogeneous catalyst for the amination of azoles under ligand free conditions

A ligand free Ru/C-catalyzed amination of 2-halo azoles with a broad scope of aminating reagents has been developed. A variety of 2-aminoazole derivatives were synthesized in moderate to good yields by utilizing this protocol. The methodology is operationally simple and not sensitive to air and moisture. It provides potentially useful products by using an inexpensive and recyclable catalytic system under ligand free conditions without significant loss of its catalytic activity up to four cycles.

Aqueous-Phase Synthesis of α-Hydroxyphosphonates Catalyzed by β-Cyclodextrin

Abstract α-Hydroxyphosphonates were synthesized from aromatic/heteroaromatic aldehydes with triethyl phosphite in the presence of β-cyclodextrin in an aqueous medium. The β-cyclodextrin can be recovered and reused without loss of catalytic activity. GRAPHICAL ABSTRACT

Conversion of Epoxides to β-Chlorohydrins with Thionyl Chloride and β-Cyclodextrin in Water.

Abstract Several epoxides are efficiently converted to the corresponding β‐chlorohydrins in impressive yields with thionyl chloride in the presence of β‐cyclodextrin using water as solvent at room temperature.