‘Greener’Solventless or Benign Media Microwave-Assisted Methods from Varma’s Laboratory
•MW-assisted Synthesis – Catalytic Applications in Aqueous Media: Coordination Chem. Rev., 291, 68-94 (2015).
•MW-assisted Chemistry: Synth. Applications for Nanomaterials and Organics: Acc. Chem. Res., 47, 1338-1348(2014).
•Solvent-free and Catalyst-free Chemistry–A Benign Pathway to Sustainability: ChemSusChem, 7, 24-44, (2014).
•Benign by Design:Catalyst-Free, In-water, On-water Green Organic Synthesis:Chem. Soc. Rev., 42, 5522-5551(2013).
•Alternate Energy Input: Mechanochemical, MW- & Ultrasound in Org. Synthesis: Chem. Soc. Rev., 41, 1559 (2012).
•Green Chemistry by Nano-Catalysis: Green Chem., 12, 743 (2010); MW Ag Nano: Acc. Chem. Res., 44, 469(2011).
•MW-assisted Rapid and Sustainable Route to Organics and Nanomaterials: Aust. J. Chem., 62, 16-26(2009).
•Aqueous MW Chemistry: Green Synth. Tool for Rapid Drug Discovery, Chem. Soc. Rev, 37, 1546-1557 (2008)
•MW-assisted Organic Synthesis & Transformations in Benign Reaction Media: Acc. Chem. Res., 41, 629-639(2008).
•Greener Syntheses of Heterocyclic Compounds Using Microwaves, Pure & Applied Chem., 80, 777-790 (2008).
•Syntheses Using Mechanochemical Mixing, Microwave- & Ultrasonic Irradiation, Green Chem Lett. Rev., 1, 37 (2008)
•Book: Alternate Energy Processes in Chem. Synth.-MW, Ultrasound and Photo Activation, Narosa Publ.,Delhi, 2008.
•Sustainable Approach to Pharmaceutically Active Heterocycles: Curr. Opin. Drug Discov. Devel., 10, pp 723-737 (2007).
•Book Chapter: MW & Supported Reagents inMicrowaves in Organic Synthesis, Wiley-VCH, Chap #8. pp 362-415(2006)
•Book Chapter: MW in Green and Sustainable ChemistryinTop Curr Chem.,Springer-Verlag, 266: pp 199-231(2006)
•Book Chapter: Solventless Reactions inGreen Separation Processes, Wiley-VCH, Chap 2.2. pp 53-87(2005)
•MW Technology-Chemical Synth Applications:Kirk-Othmer Encycop.Chemical Technology, 5thEd,16,, 538-594(2006)
•Book:“Advances in Green Chemistry: Chem. Synth. Using MW Irradiation” AstraZeneca Res. Foundn, India (2002)
•Clay and Clay-supported Reagents in Organic Syntheses, Tetrahedron Report # 598,Vol. 58, 1235-55(2002)
•Solvent-free Organic Syntheses Using Supported Reagents and Microwaves: Green Chemistry, 43-55 (1999)
CLEAVAGE–PROTECTION/DEPROTECTION:
•Chemoselective Cbz-Protection of Amine using Silica-Sulfuric Acid at Room Temp.: Tetrahedron Lett.,48, 8170 (2007)
•Synthesis of Thio-ketones, Lactones, Amides & Thionoesters–Lawesson's reagent: Organic Letters, 1, 697 (1999)
•Deoximation to Carbonyls Using Ammonium Persulfate/Silica: Tetrahedron Lett.,38, 5427 (1997)
•Dethioacetalization to Carbonyls-Clayfen[Iron(III) nitrate/clay]: Tetrahedron Lett.,38, 2623 (1997)
•Deacylation of Esters-Alumina:Perkin Trans.-1, 999, (1993);Desilylation (Alcohols)-Alumina: Tet. Lett.34, 3029 (1993)
CONDENSATION–CYCLIZATION-DEHYDRATION:
•Mixing with MW-Solvent-free & Catalyst-free Synth. of Pyrazoles and Diazepines: Tetrahedron Lett., 54, 1538 (2013)
•Cat.-free One-pot Synth. of - & -Hydroxy Sulfides from Iodonium Salts with MW: Eurp. J. Org. Chem., 6852 (2012)
•Ring-fused Aminals: Catalyst & Solvent-free MW-amination of N-Heterocycles: Tetrahedron Lett., 49, 7165 (2008)
•Michael Addition Reaction of -Unsaturated Carbonyl Compounds by PEG: Tetrahedron Lett., 49, 6974(2008)
•MW Solvent-free Ritter reaction-Synthesis of Amides from Alcohols and Nitriles: Tetrahedron Lett., 49, 2661 (2008)
•MW One-pot Solvent-free Synthesis of 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles: Tetrahedron Lett., 49, 879 (2008)
•Synth of Pyrazoles and Diazepines in Aqueous Medium-Polystyrene Sulfonic Acid: Tetrahedron Lett., 49, 397 (2008)
•Synthesis of Ureas, Cyclic Ureas & Urethanes from Diamines in presence of ZnO: Tetrahedron Lett.,45, 7205 (2004)
•Propargylamine via-Cu-Cat. Coupling of Aldehyde, Alkyne & Amines:QSAR & Combinatorial Science, 23, 891 (2004)
•Catalyst-free & Solvent-free Synth. Heterocyclic Hydrazones: Chem. Commun.,1716 (2001);Green Chem., 4, 35 (2002)
•3-Compont. Ugi Rxn.–Imidazo[1,2-a]annulated Pyridines, Pyrazines & Pyrimidines:Tetrahedron Lett.,40, 7665 (1999)
•Biginelli Rxn.– Synth of 4-Ph-3,4-dihydropyrimidin-2-ones:Synthesis, 1799 (1999);Tetrahedron Lett., 48, 7343 (2007)
•Synthesis of N-Sulfonylamines Using Clay, Carbonate and Orthoformate:Tetrahedron Lett.,40, 4951 (1999)
•SolidState Synthesis of 2-Aroylbenzofurans, Thiazoles etc. J. Chem. Soc. Perkin Trans-1, 4093 (1998)
•One-Pot Synthesis of 2-Amino Substituted Isoflav-3-enes from Enamines: J. Org. Chem.63, 8038, (1998)
•Synthesis of Nitroalkenes from Carbonyl Compounds (Henry Reaction): Tetrahedron Lett.,38, 5131 (1997)
•Synthesis of 2-Ph-1,2,3,4-Tetrahydro-4-Quinolones from 2'-Aminochalcones–Clay: Synlett, 857 (1997)
OXIDATION:
•Ferrate: Greener Oxidants with Multimodal Action in Water Treatment Technologies: Acc. Chem. Res.,48,182 (2015).
•Oxidation of Styrenes with SiO2-Supported Iron Oxide Nanocatalysts in water: Adv. Synth. Cat.,354, 1707 (2012).
•Process Intensification-Oxidation Benzyl Alcohol-Continuous Isothermal Reactor-MW: Green Chem., 8, 29 (2006)
•Oxidation of Dihydropyridines to Pyridines with Sulfur: J. Chem. Soc. Perkin Trans-1, 1755 (1999)
•General Oxidation Reaction-Claycop [Copper(II) nitrate/Clay]/H2O2: Tetrahedron Lett.,39, 1307 (1998)
•Oxidn. of Sulfides & Alcohols by[PhI(OAc)2]/Al2O3: J. Chem. Res. (S), 120 (1998); Tetrahedron Lett.,38, 7029 (1997)
•Oxidation of Sulfides to Sulfoxides & Sulfones–Wet NaIO4/SiO2: Tetrahedron Lett., 38, 6525 (1997)
•Oxidation of Alcohols–Clayfen:Tetrahedron Lett., 38, 2043 (1997); using Fe(NO3)3: Tetrahedron Lett.,48, 8839 (2007)
REDUCTION:
•Revisiting Meerwien-Ponndorf-Verley Redn.-Sustainable Transfer Hydrogenation: Green Chem., 11, 1313(2009)
•Hydrodechlorination of Chlorinated Benzenes in Continuous MW reactor: Green Chem., 6, 295(2004)
•Reduction of Nitrocompounds to Amines on Alumina-supported Hydrazine: Tetrahedron Lett. 42, 5347 (2001)
•Sec- & Tert-Amines via Reductive Amination of Carbonyls-NaBH4/Wet Clay: Tetrahedron,54, 6293 (1998)
•Redn. Carbonyls—NaBH4/Al2O3:Tetrahedron Lett.,38, 4337 (1997); Cannizzaro Rxn:Tetrahedron Lett. 39, 8437 (1998)
IONIC LIQUIDS:
•Indate(III) Ionic Liquids-Coupling of CO2 with Epoxides-Cyclic Carbonate Formation,J. Org. Chem.,70, 7882 (2005)
•Indium IL-Tetrahydropyranyl,Tetrahedron Lett., 46, 1467, 2005; Gallium IL-Acetals, Tetrahedron Lett., 46, 7447, 2005
•Aldol- & Mannich-type Reactions via in situ Olefin Migration in Ionic Liquids, Organic Letters, 5, 657(2003).
•Solvent-free Route to Ionic Liquids Using MW & Tetrahydropyranylation, Chem. Commun.,643 (2001); 342 (2002)
•MW Solvent-free Prep of IL’s:Pure Appl. Chem., 73, 1309(2001);Sonochemical Prepn. of IL’s:Org. Lett.4, 3161(2002)
---Related Environmentally Benign Organic Reactions Using Alternate Reaction Media(water),Clay, or Zeolites---
•Aqueous Ring Closing Metathesis & Hydrosilylation with Grubbs 2nd Gen. Ru Catalyst: J. Org. Chem.,73, 7417 (2008)
•Pd-N-Heterocyclic Carbene (NHC) Organic Silica: Appls. in C-C Coupling Reactions: Tetrahedron 64, 4637(2008)
•Tandem Bis-Aldol Reaction of Ketones: MW Synth. of 1,3-Dioxanes in Aqueous Medium:J. Org. Chem.72,7420 (2007)
•Nuc.Subst.Rxns-MW Aqueous Media Synthesis Alkyl Azides, Thiocyanates and Sulfones:J. Org. Chem.71,6697 (2006)
•MW Synthesis Pyrazole, Pyrazolidine etc. using Hydrazine: Tet .Lett., 46, 6011 (2005); J. Org. Chem.71, 135 (2006)
•Synthesis of N-aryl Azacycloalkanes, MW-assisted N-heterocyclization of Anilines: Organic Letters, 7, 2409 (2005)
•Feature: Environmentally Friendlier Transformations on Mineral Supports, J. Mat.Chem.,12, 3199(2002).
•Microwave-Accelerated Suzuki Cross-coupling Reaction in PEG: Green Chemistry, 3, 146 (2001)
•Urea-H2O2: SolidState Oxidns for Nitriles, Sulfides & N-Heterocycles & (Dakin Reaction)Organic Lett.,1, 189 (1999)
•Pd Intercalated Clayfor Heck Rxn:Tetrahedron Lett.,40, 2075(1999); Suzuki Rxn:Tetrahedron Lett., 40, 439(1999).
•Sulfidesvia Ce-exchan. NaY Catalyst: Chem. Commun., 621 (1997);Sulfoxides-Urea H2O2Chem. Commun., 471 (1997)
Ultrasound-promoted Reactions:
•Mag. Nano Pd-Heck-type Arylation of Alkenes with diaryliodonium Salts in Water/PEG:Green Chem, 14, 2133 (2012)
•Cu-Catalyzed Ultrasound-ExpeditedN-Arylation of Sulfoximines: Adv. Synth. Cat.,354, 986-990 (2012).
•Ultrasound-expedited Epoxidation of Olefins over Hydrotalcites and H2O2,Synth. Commun., 33, 2017(2003)
•Can Ultrasound Substitute for PTC? Catalysis & Sonic Nucl. Subst.Rxn-Azides: J. Mol. Cat. A. Chem., 149,153 (1999)
•Ultrasound-accelerated Aqueous KMnO4 Oxidn. of Styrenes to 1,2-Diols: Tetrahedron Lett. 39, 7463 (1998)
Nanomaterials via Novel ‘Greener’ Routes and their Application as Nano-Catalysts:
•Nano TiO2 Films: Application in Remediation of Organic Pollutants: Coordination Chem. Rev., 306, 43-64 (2016).
•Magnetically Retrievable Catalysts for Asymmetric Synthesis: Coordination Chem. Rev., 287, 137-156(2015).
•Fate of Engineered Nanoparticles – Implications in the Environment: Coordination Chem. Rev., 287, 64-78(2015).
•Journey on Greener Pathways-Perspective article for 15 Years GC Celebration: Green Chem., 16, 2027-2041 (2014)
•Separation & Measurement of Ag Nanoparticles with Magnetic Particles: Sci. Total Env.472, 316 (2014)
•Ag Surfaces H2O Disinfection:Curr.Opin.Chem.Eng.3,25(2014);Microcystin removal-TiO2Chem.Comm.,49,10118 (2013)
•Book: Sustainable Preparation of Metal Nanoparticles: Methods & Applications-RSC Green Chemistry Series (2013)
•Nano-Magnetite Supports in the Development of Sustainable Methodologies.Chem Soc. Rev.42, 3317 (2013)
•ControlledAg Nanowires-Glycerol & MW:Chem.Commun.,49,692(2013);(Au,Pt,Pd):ACS Sus.Chem.Eng.,1, 810(2013)
•Beet Juice-Synth. Plasmonic AgCl/Ag:ChemSusChem, 5,2435(2012);Nanometals(Pd,Pt,Au,Ag):RSC Adv.2,10283 (2012)
•Magnetic Nano Supp. Glutathione-Homocoupling of Boronic Acids in water:Green Chem, 12, 1540 (2010)-Cover Page
•Synth. Charact. & Biocompatibility of “Green” Ag Nanoparticles Using Tea Polyphenols: Nanoscale, 2, 763(2010)
•In Vitro Biocompatibility of NZVI, Fe Synthesized Using Tea Polyphenols: Green Chem., 12, 114 (2010)-Hot Paper.
•Rags to Riches Story: Metal Nanoparticles from Waste-Using Grape Pomace Extract, ChemSusChem, 2, 1041 (2009)
•Degradation Bromothymol Blue with Zerovalent Iron Generated by Tea Polyphenols: J. Mater. Chem, 19, 8671(2009)
•Magnetic Nano Supp. Glutathione-Sustain. Organocatalyst: Chem Commun.1837(2009);Tetrahedron, 66, 1091 (2010)
•Self-Assembly of Metal Oxides in to 3-dimensional Nanostructures: Synth. & Appl. Catalysis: ACS Nano,3,728(2009)
•Nano Mag Recov. Ru OH: Hydration of Nitriles to Amides in water:Chemistry: A Europ. Journal,15, 1582 (2009).
•Synth. & Functionalization of Magnetic Nanoferrites via MW Hydrothermal: J. Phys. Chem.C, 112,18399(2008)
•Green Synthesis of Ag & Pd Nanoparticles at Room Temp. Using Coffee & Tea Extract: Green Chem., 10, 859 (2008)
•Synth of Core (Fe, Cu)-Shell (Au, Pt, Pd and Ag) Nanocrystals- Aqueous Vit. C:Crystal Growth Design,7, 2582 (2007)
•MW Synth of Carboxymethyl Cellulose/Metal Biodegradable Nanocomposites,Biomacromolecules,8, 2762(2007)
•Bulk Synth. Noble Nanocrystals with Microwaves & Aqueous Sugar Solutions. Crystal Growth & Design,7, 686(2007)
•Au & Pt Nanomaterials Using Vit B2: Density-assisted assembly of Spheres, Wires Rods: Green Chem., 8, 516 2006)
Mechanochemical Solvent-Free Mixing (grinding):
•PhI(OH)OTs-Synthof -Tosyl.-Ketosulfones Tet. Lett., 47, 8239 (2006); of-Ketosulfones: Tet Lett. 47, 4197 (2006)
•Solvent-free Synth of Aryl-4-Me-1,2,4-Triazolo[4,3-a]Quinoxalines Using PhI(OAc)2: Green Chem.,6, 156 (2004)
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