S. Narayana Murthy

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