1. Green Chemistry: Microwave Assisted Organometallic Reaction

2. Green Chemistry
To promote innovative chemical technologies that reduce or eliminate the use or generation of hazardous substances in the design, manufacture, and use of chemical products.

3. What does the Chemical Industry do for us?

4. Green chemistry is about Waste Minimisation at Source
Use of Catalysts in place of Reagents
Using Non-Toxic Reagents
Use of Renewable Resources
Improved Atom Efficiency
Use of Solvent Free or Recyclable Environmentally Benign Solvent systems

5. Green Chemistry = Responsibility
Why is there no ‘Green Geology’ or ‘Green Astronomy’?
Because chemistry is the science that introduces new substances into the world and we have a responsibility for their impact in the world.”
- Ronald Breslow

6. Green Chemistry is also called…
A new approach to designing chemicals and chemical transformations that are beneficial for human health and the environment
An innovative way to design molecules and chemical transformations for sustainability
Meeting the needs of the current generation without compromising the ability of future generations to meet their own needs
Benign by design
Pollution prevention at the molecular level

7. What is Green Chemistry?
Green chemistry is the study of how to design chemical products and processes in ways that are sustainable and not harmful for humans and the environment.
Three components: catalysis, solvents, non-toxic
12 principles of green chemistry

8. Green Chemistry Is About...
Waste
Materials
Hazard
Reducing
Risk
Energy
Cost

9. Why do we need Green Chemistry ?
Chemistry is a very prominent part of our daily lives.
Chemical developments also bring new environmental problems and harmful unexpected side effects, which result in the need for ‘greener’ chemical products.
A famous example is the pesticide DDT.

10. The 12 Principles of Green Chemistry (1-6)

11. The 12 Principles of Green Chemistry (7-12)
7 Use of Renewable Feedstocks
A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.
8 Reduce Derivatives
Unnecessary derivatization (use of blocking groups, protection/de-protection, and temporary modification of physical/chemical processes) should be minimised or avoided if possible, because such steps require additional reagents and can generate waste.
9 Catalysis
Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
10 Design for Degradation
Chemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in the environment.
11 Real-time Analysis for Pollution Prevention
Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.
12 Inherently Safer Chemistry for Accident Prevention
Substances and the form of a substance used in a chemical process should be chosen to minimise the potential for chemical accidents, including releases, explosions, and fires.

12. What is “Green”? Sustainable
Kinder and gentler to people and the planet

13. Green Chemistry

14. The cost of using hazardous materials:

15. Conventional Heating vs Alternative Energy Source
Bunsen burner
Oil bath
Heating mantle
Alternative Energy Sources
Microwave
Ultrasound
Sunlight / UV
Electonchemistry

16. Clean Chemical Synthesis Using Alternative Reaction Methods
Alternative Energy Sources
Microwave
Ultrasound
Sunlight / UV
AlternativeReactionMedia/Solvent-free
Supercritical Fluids
Ionic Liquids
Water
Polyethylene glycol (PEG)
Solvent free

17. Microwaves in Synthesis

18. History or how it all began…
While fire is now rarely used in synthetic chemistry, it was not until Robert Bunsen invented the burner in 1855 that the energy from this heat source could be applied
There is some controversy about the origins of the microwave power cavity called the magnetron – the high-power generator of microwave power.
The British were particularly forward-looking in deploying radar for air defense with a system called Chain Home which began operation in 1937.
Originally operating at 22 MHz, frequencies increased to 55 MHz.
1921 was published by A.W. Hull the earliest description of the magnetron, a diode with a cylindrical anode
1940 It was developed practically by Randall and Booth at the University of Birmingham in England ; they verified their first microwave transmissions: 500 W at 3 GHz.
A prototype was brought to the United States in September of that year to define an agreement whereby United States industrial capability would undertake the development of microwave radar.
1940 the Radiation Laboratory was established at the Massachusetts Institute of Technology to exploit microwave radar. More than 40 types of tube would be produced, particularly in the S-band (i.e. 300 MHz). The growth of microwave radar is linked with Raytheon Company and P.L. Spencer who found the key to mass production.

19. History or how it all began…
1946 Dr. Percy Spencer-the magnetron inventor; he has found a variety of technical applications in the chemical and related industries since the 1950s, in particular in the food-processing, drying, and polymer
surprisingly, microwave heating has only been implemented in organic synthesis since the mid-1980s.
Today, a large body of work on microwave-assisted synthesis exists in the published and patent literature.
Many review articles, several books and information on the world-wide-web already provide extensive coverage of the subject.

20. 1969 “ Carrying out chemical reactions using microwave energy ” J. W
1969 “ Carrying out chemical reactions using microwave energy ” J.W. Vanderhoff – Dow Chemical Company US 3,432,413
1986 “The Use of Microwave Ovens for Rapid Organic Synthesis” Gedye, R. N. et alTetrahedron Lett. 1986, 27, 279
1986 “Application of Commercial Microwave Ovens to Organic Synthesis” Giguere, R. J. and Majetich, G. Tetrahedron Lett. 1986, 27, 4945

21. Energy Use in Conventional Chemical Processes
Heating
Stirring
Piping
Transporting
Cooling

22. Problem of Conventional Heating
You heat what you don’t want to heat.
Solvents for reactions, apparatus: heated up and cool it down.
Double energy penalty without any apparent “benefit”.

24. Energy Consumptions
Three ways to get the reaction done, but different energy bills to pay

25. Microwaves MW reactors operate at 2.45 GHz.
Electric field oscillates at 4.9 x 109 times/sec – 10oC/sec heating rate.

27. Electromagnetic Spectrum
Neas, E.; Collins, M. Introduction to Microwave Sample Preparation: Theory and Practice, 1988, p. 8.

28. Schematic of a Microwave
E= electric field
H= magnetic field
l= wavelength (12.2 cm for 2450 MHz)
c= speed of light (300,000 km/s)

29. Microwaves Application in Heating Food
1946: Original patent (P. L. Spencer)
1947: First commercial oven
1955: Home models
1967: Desktop model
1975: U.S. sales exceed gas ranges
1976: 60% of U.S. households have
microwave ovens

30. Spectrum Electromagnetic
Electric field component
Responsible for dielectric heating
Dipolar polarization
Conduction
Magnetic field component

31. Microwaves – Dipolar Rotation
Polar molecules have intermolecular forces which give any motion of the molecule some inertia.
Under a very high frequency electric field, the polar molecule will attempt to follow the field, but intermolecular inertia stops any significant motion before the field has reversed, and no net motion results.
If the frequency of field oscillation is very low, then the molecules will be polarized uniformly, and no random motion results.
In the intermediate case, the frequency of the field will be such that the molecules will be almost, but not quite, able to keep in phase with the field polarity.
In this case, the random motion resulting as molecules jostle to attempt in vain to follow the field provides strong agitation and intense heating of the sample.
At 2.45 GHz the field oscillates 4.9 x 109 times/s which can lead to heating
rates of 10 °C per second when powerful waves are used

32. MW Heating Mechanism Two mechanisms: Dipolar rotation / polarization
Continuous electric
field
Noconstraint
Alternating electric field
Withhigh frequency
Two mechanisms:
Dipolar rotation / polarization
Ionic Conduction mechanism

33. Microwave Dielectric Heating Mechanisms
Conduction Mechanism
Dipolar Polarization
Mechanism
Dipolar molecules try to
align to an oscillating field
by rotation
Ions in solution will move
by the applied electric
field
Mingos, D. M. P. et al., Chem. Soc. Rev. 1991, 20, 1 and 1998, 27, 213

34. Microwave vs Oil-bath Heating
J.-S. Schanche, Mol. Diversity 2003, 7, 293.

35. Conventional Heating by Conduction
Conductive
heat
Heating by
convection
currents
Slow and
energy
inefficient
process
temperature on the outside surface is
in excess of the boiling point of liquid

36. Direct Heating by Microwave Irradiation
Solvent/reagent
absorbs MW energy
Vessel wall transparent to MW
Direct in-core heating
Instant on-off
Inverted temperature gradients!

37. Molecular Speeds

38. Molecular Speeds

39. Microwave Ovens Cooking Food! Cooking Chemistry ??? Household MW ovens
The Use of Microwave Ovens for Rapid Organic Synthesis R. Gedye et al., Tetrahedron Lett. 1986, 27, 279.

40. Publications on MW-Assisted Organic Synthesis
7 Synthetic Journals: J.Org.Chem.,Org.Lett.,Tetrahedron Lett.,Tetrahedron, Synth.Commun., Synlett, Synthesis
All Journals (Full Text): Dedicated instruments only (Anton Paar, Biotage, CEM, Milestone, Prolabo)

42. Industrial /Chemical / Applications of Microwave Heating
Food Processing
+ Defrosting
+ Drying / roasting / baking
+ Pasteurization
Plasma
+ Semiconductors
Waste Remediation
+ Sewage treatment
Drying Industry
+ Wood, fibers, textiles
+ Pharmaceuticals
+ Brick / concrete walls
Analytical Chemistry
+ Digestion
+ Extraction
+ Ashing
Polymer Chemistry
+ Rubber curing, vulcanization
+ Polymerization
Biochemistry / Pathology
+ Protein hydrolysis
+ PCR, proteomics
+ Tissue fixation
+ Histoprocessing
Ceramics/Materials
+ Alumina sintering
+ Welding, smelting, gluing
Medical
+ Diathermy, tumor detection
+ Blood warming
+ Sterilization (Anthrax)
+ Drying of catheters

43. Books on Microwave- Assisted Synthesis
(ACS Professional Reference Book) H. M. Kingston, S. J. Haswell (eds.)
Hayes, B. L.,
CEM Publishing,
Matthews, NC,
2002
Microwaves in Organic and Medicinal Chemistry
Kappe, C. O. and Stadler, A.
Wiley-VCH, Weinheim, 2005, ISBN:
410 pages, ca 1000 references,
􀂃 Fundamentals of Microwave Application
􀂃 Alternative Laboratory Microwave
Instruments
􀂃 Chemistry Applications
􀂃 Biochemistry Applications
􀂃 Laboratory Microwave Safety

44. Books on Microwave- Assisted Synthesis
Lidstöm, P.;
Tierney, J. P.
(Eds.),
Blackwell
Scientific,
2005
Loupy Andre (Ed.)
Wiley-VCH, Weinheim, 2003, ISBN:
523 pages, 2000 refs.
Book (2 volumes) Wiley-VCHA.
Loupy edit
Second Edition
(2006) 22 Chapters

45. Books on Microwave-Assisted Synthesis
Practical Microwave Synthesis for Organic Chemists - Strategies, Instruments, and Protocols 
Edition , X, 310 Pages, Hardcover, Monograph
Astra Zeneca Research
Foundation Kavitha Printers,
Bangalore, India, 2002

46. Microwave Ovens

47. Monomodal instrument Piccoli volumi processabili
- Onde Stazionarie (Hot Spots)
- Difficoltà nello Scale-up
+ Alta densità d’energia
Images adapted from: C.O. Kappe, A. Stadler: Microwaves in Organic and Medicinal Chemistry, Wiley, 2005

48. Multimodal instrument
+ Alta densità d’energia (maggior potenza disponibile)
+ Maggiori volumi processabili (cavità a MW più grande)
+ No Onde Stazionarie (No Hot-spots)
+ Semplice Scale-up
- Volume minimo processabile

49. Monomodal Vs. Multimodal

50. Monomodal Vs. Multimodal

51. Thermal Effects
More efficient energetic coupling of solvent with microwaves promotes higher rate of temperature increase
• Inverted heat transfer, volumetric
• “Hot spots” in monomode microwaves
• Selective on properties of material (solvents, catalysts, reagents, intermediates, products, susceptors)

53. Recent Applications of Microwave- Assisted Synthesis-MAOS

54. Hydrolysis of benzamide
R. Gedye, F. Smith, K. Westaway, H. Ali, L. Baldisera, L. Laberge, J. Rousell, Tetrahedron Lett. 1986, 27, 279–282. R. J. Giguere, T. L. Bray, S. M. Duncan,
G. Majetich, Tetrahedron Lett. 1986, 27, 4945–4958.
thermal: 1 h, 90 % yield (reflux)
MW: 10 min, 99 % yield (sealed vessel)
The first reports on the use of microwave heating to accelerate organic chemical transformations (MAOS) were published by the groups of Richard Gedye (and Raymond J. Giguere/George Majetich in In those early days, experiments were typically carried out in sealed Teflon or glass vessels in a domestic household microwave oven without any temperature or pressure measurements. The results were often violent explosions due to the rapid uncontrolled heating of organic solvents under closed-vessel conditions.

55. Solvent-free Reactions or Solid-Solid Reactions
“No reaction proceeds without solvent”
Aristotle
Green chemistry
enabled advancement
Solventless syntheses

56. Solvent-free Organic Synthesis
Chemical Synthesis w i t h o u t t h e u s e o f solvents has developed
i n t o a p o w e r f u l
m e t h o d o l o g y a s i t reduces the amount of toxic waste produced and therefore becomes less harmful to the
e n v i r o n m e n t

57. Solvent-free Organic Synthesis
Best solvent is no solvent!
Clean and efficient synthesis
Economic and environmental impact
Fast reaction kinetics

58. Adolf von Baeyer

59. Synthesis of Indigo

60. Towards benign synthesis with remarkable Versatility
G. W. V. Cave, C. L.
Raston, J. L. Scott
Chem.Commun.
2001, 2159

61. Solid-State General Oxidation with with Urea H2O2 Complex
R. S. Varma and K. P. Naiker, Org. Letters, 1999, 1, 189.

62. Solvent-free Oxidative Preparation of Heterocycles
Kumar, Chandra Sekhar, Dhillon, Rao, and Varma,Green Chem., 2004, 6,

63. Solvent-free Synthesis of ß-Keto Keto Sulfones Ketones
Kumar, Sundaree, Rao and Varma,Tetrahedron Letters, 2006, 47,

64. Solvent-free Reduction
F. Toda et al. Angew. Chem. Int. Ed. Engl., 1989, 28, 320and Chem. Commun., 1989, 1245.

65. Carbon-Carbon Bond Formation
Toda, Tanada, Iwata, J. Org. Chem., 1989, 54, 3007.

66. Solventless Photo Coupling and Photo Rearangements
Y. Ito, S. Endo, J. Am. Chem. Soc. 1997, 119, 5974.
Shin, Keating, Maribay, J. Am. Chem. Soc. 1996, 118, 7626.

67. Solvent - Free Condensation
Z. Gross, et al., Org. Letters, 1999, 1, 599.

68. Solid-State Preparation of Dumb-bell-shaped C120
Wang, Komatsu, Murata, Shiro, Nature 1997, 387, 583

69. Advantages of Solid Mineral Supports (Alumina, Silica and Clay)
Good dispersion of active (reagent) site can lead to significant improvement of reactivity–large surface area.
The constraints of the (molecular dimensions) pores and the characteristics of the surface adsorption can lead to useful improvement in reaction selectivity.
Solids are generally easier and safer to handle than liquids or gaseous reagents.
Inexpensive, recyclable and environmentally benign nature.

70. Solid-supported Solventless Reactions
Microwave irradiation of solventless reactions with inorganic mineral supports such as alumina, silica, or clays have resulted in faster reactions with higher yields with simplified separation.
R. S. Varma, Tetrahedron, 2002, 58, 1235.
R. S. Varma, Green Chem., 1999, 1, 43.

71. Supported Reactions Using Microwaves
E. Gutterrez, A. Loupy, G. Bram, E. Ruiz-Hitzky, Tetrahedron Lett. 1989, 30, 945.

72. Microwave-Assisted Deacetylation on Alumina
Varma et al.: J. Chem. Soc., Perkin Trans. 1, 999 (1993)

73. Deprotection of Benzyl Esters via Microwave Thermolysis
A practical alternative to traditional catalytic hydrogenation
Varma et al.: Tetrahedron Lett., 34, 4603 (1993)

74. Solid State Deoximation with Ammonium Persulfate-Silica gel Regeneration of Carbonyl Compounds Using Microwaves
Varma, Meshram: Tetrahedron Lett., 38, 5427 (1997)

75. Solid State Cleavage of Semicarbazones/Phenylhydrazones with Amm
Solid State Cleavage of Semicarbazones/Phenylhydrazones with Amm. Persulfate–Clay using Microwave and Ultrasonic Irradiation
Varma, Meshram: Tetrahedron Lett., 38, 7973 (1997)

76. Solid Supported Solvent-free Oxidation under MW
Varma et al., Tetrahedron Lett., 1997, 38, 2043 and 7823

77. Solvent-free Reduction Using MW
Chemoselective reduction of trans-cinnamaldehyde: olefinic moiety remains intact and the aldehyde functionality is reduced in a facile reaction.
Varma et al., Tetrahedron Lett., 1997, 38, 4337

78. Hydrodechlorination under continuous MW
Pillai, Sahle-Demessie, Varma: Green Chemistry, 6, 295 (2004)

79. Synthesis of Heterocyclic Compounds
Varma et al.: J. Chem. Soc. Perkin Trans 1, 4093 (1998)
Varma, J. Heterocycl. Chem., 36, 1565 (1999)

80. Synthesis of Heterocyclic Compounds

81. Organometallic Reactions

82. Rearrangements

83. Rearrangements

84. Heterocyclic systems, 10- p electronics
INDOLIZINES
Heterocyclic systems, 10- p electronics
Structure of many naturals alkaloids : (-) slaframine, (-) dendroprimine, indalozine, coniceine
Key intermediates in indolizidines, bisindolizines, ciclofans, ciclazines synthesis- biologic actives compounds

85. Why interest for indolizinic products
Strong fluorescent properties
luminiscent products
Potentially fluorescents marker
Potentially laser“scintillaters”
Strong inhibitors for lipid peroxydation (15-lipooxygenase inhibitors )
Biologic actives products
Ligands for estrogen receptors
Possible inhibitory activity for phospholipase A2
“Calcium-entry” blockers
Bioorg. & Med. Chem. Lett., 16, 59, 2006
Tetrahedron, 61, 4643, 2005
Bioorg. & Med. Chem., 10, 2905, 2002
J. Org. Chem., 69, 2332, 2004
Dyes and Pigments, 46, 23, 2000
J. of Luminiscence, 82, 155, 1999

86. Indolizines by irradiation with microwaves, in MCR
U. Bora, A. Saikia, R. C. Boruah – Organic Lett., 5 (4), 435, 2003;
Asymmetric indolizines, by irradiation with microwaves, in MCR
A. Rotaru, I. Druţă, T. Oeser, T. Muller – Helv. Chim. Acta, 88, 1798, 2005;

87. Synthesis of new indolizines
[3+2] dipolar cycloaddition of symmetrical or non-symmetrical 4,4’-bipyridinium-methyne-ylids with actives alkynes, symmetrical or non-symmetrical :
I. Druţă, R. Dinică, E. Bâcu, I. Humelnicu – Tetrahedron, 54, 10811, 1998
R. Dinică, C. Pettinari – Heterocycl. Comm., 07(4), 381, 2001
A. V. Rotaru, R. P. Dănac, I. Druţă – J. Heterocyclic Chem., 41, 893, 2004
A. Rotaru, I. Druţă, T. Oeser, T. Muller – Helv. Chim. Acta, 88, 1798, 2005

88. Synthesis of new substituted pyridinium-indolizines
Indolizinic cycloadducts using like dipolarophile 4-nitro-phenyl propiolate

89. Indolizine synthesis in solid phase, under microwaves

90. Monoindolizine synthesis in solid phase, under microwaves
Reaction conditions and the yelds for synthesized compounds (12a-d)
Comp.
Solution
Solid phase
Microwaves
Time
(min) T
(°C) h
(%)
12a
480 50 63 10 95 57 84
12b 61 77
12c 55 71 52 85
12d 60 53 47
B. Furdui, R. Dinică, I. Druţă, M. Demeunynck –Synthesis, 16, 2640, 2006

91. Benefits of MW-Assisted Reactions
Higher temperatures (superheating / sealed vessels)
􀂉 Faster reactions, higher yields, any solvent (bp)
􀂉 Absolute control over reaction parameters
􀂉 Selective heating/activation of catalysts, specific effects
􀂉 Energy efficient, rapid energy transfer
􀂉 Can do things that you can not do conventionally
􀂉 Automation / parallel synthesis – combichem

92. MW-Assisted Solvent-free Three Component Coupling: Formation of Propargylamines
Ju, Li and Varma, QSAR & Combinatorial Science, 2004, 23, 891

93. Solvent-free Synthesis of Ionic Liquids
Varma, Namboodiri, Chem. Commun., 2001, 643.
Varma, Namboodiri, Pure Appl. Chem., 2001, 73, 1307.
Namboodiri, Varma, Chem. Commun., 2002, 342.

94. MW Synthesis of Tetrahalideindate(III)-based IL
Kim and Varma. J. Org. Chem., 2005, 70, 7882.

95. PEG, a Biodegradable “Solvent”
􀂾 PEG has been applied in bioseparations.
􀂾 PEG is on the FDA’s GRAS list, (compounds Generally
Recognized as Safe) and has been approved by the FDA for
Internal consumption.
􀂾 PEG is weakly, immunogenic, a factor which has enabled
the development of PEG–protein conjugates as drugs.
􀂾 Aqueous solutions of PEG are biocompatible and are
utilized in tissue culture media and for organ preservation.
􀂾 PEGs are nonvolatile
􀂾 PEG has low flammability
􀂾 PEG is biodegradable
J. Chen, S. K. Spear, J. G. Huddleston, R.D. Rogers, Green Chem , 7, 64.

96. Suzuki Cross-Coupling Reaction in PEG Accelerated by Microwaves
V. Namboodiri, R. S. Varma: Green Chemistry, 2001, 3, 146.

97. Advantages of Present Approach
PEG offers a convenient recyclable reaction medium
Good substitute for volatile organic solvents
The microwave heating offers a rapid and clean alternative at high solid concentration and reduces the reaction times from hours to minutes
The recyclability of the catalyst makes the reaction economically and potentially viable for commercial applications

99. Water as a “cleaner” solvent
Water is not a popular choice of solvent,
reactivity in heterogeneous aqueous media is
not very well understood
But It brings biochemistry and organic
chemistry closer together in the beneficial use
of water as the reaction medium, it is abundant,
inexpensive and clean.

100. Cu (I) Catalyzed Click Chemistry
P. Appukkuttan, W. Dehaen, V. V. Fokin, E. Van der Eycken.
Org. Lett. 2004, 6, 4223.

101. N-alkylation of Amines using Alkyl Halides
Ju, Y.; Varma, R. S., Green Chem. 2004, 6,

102. Aqueous N-alkylation of Amines using Microwave Irradiation
Ju, Y.; Varma, R. S., Green Chem. 2004, 6,

103. Why Amines and Heterocycles ?

105. MW Synthesis of N-Aryl Azacycloalkanes
Ju; Varma, Tetrahedron. Lett., 2005, 46, 6011.
Ju; Varma, J. Org. Chem., 2006, 71, 135.

106. Choice of Reaction Media

107. MW -assisted one-pot synthesis of triazoles

110. Designing a “greener” synthesis
Plan!
Maximize convergence
Consider using renewable starting materials
Avoid super toxic reagents
Strive for high atom economy
Use catalytic over stoichiometric
Avoid auxiliaries and protecting groups
Consider greener solvents
Minimize number of purifications

111. Take Aways
“Green chemistry” is not so far away from what we do everyday
High yields
Minimal number of steps
Minimize number of purifications
Green principles to keep in mind
Strive for atom economy
Consider the toxicity and necessity of reagents and solvents

112. Green Chemistry Opportunities
Conferences
Annual ACS Green Chemistry and Engineering Conference
Annual Gordon Conferenece, Green Chemistry
Funding
PRF green chemistry grants
NSF green chemistry grants
EPA funding

113. Conclusion
Green chemistry Not a solution to all environmental problems But the most fundamental approach to preventing pollution.

114. Today, a large body of work on microwave-assisted synthesis exists in the published and patent literature.
Many review articles, several books and information on the world-wide-web already provide extensive coverage of the subject.

115. Lead References
Lidström, P.; Tierney, J.P.; Wathey, B.; Westman, J. Tetrahedron 2001, 57, 9225
Hayes, Brittany, L. Microwave Synthesis. Chemistry at the Speed of Light. North Carolina: CEM Publishing, 2002.
Tierney, J.P., and P. Lidström, ed. Microwave Assisted Organic Synthesis. Oxford: Blackwell Publishing Ltd, 2005.
de la Hoz, A.; Diaz-Ortiz, A.; Moreno, A. Chem. Soc. Rev. 2005, 34, 164.

116. Lead References reviews
A. Loupy, A. Petit, J. Hamelin, F. Texier- Boullet, P. Jacquault, D. Math_, Synthesis1998, 1213–1234; R. S. Varma, Green Chem. 1999, 43–55; M. Kidawi, Pure Appl. Chem. 2001, 73, 147–151; R. S. Varma, Pure Appl. Chem. 2001, 73, 193–198; R. S. Varma, Tetrahedron 2002, 58, 1235–1255; R. S. Varma, Advances in Green Chemistry: Chemical Syntheses Using Microwave Irradiation, Kavitha Printers, Bangalore, A. K. Bose, B. K. Banik, N. Lavlinskaia, M. Jayaraman, M. S. Manhas, Chemtech 1997, 27, 18–24; A. K. Bose, M. S. Manhas, S. N. Ganguly, A. H. Sharma, B. K. Banik, Synthesis 2002, 1578–1591. C. R. Strauss, R. W. Trainor, Aust. J. Chem. 1995, 48, 1665–1692; C. R. Strauss, Aust. J. Chem. 1999, 52, 83–96; C. R. Strauss,

117. References books
Microwaves in Combinatorial and High-Throughput Synthesis (Ed.: C. O. Kappe), Kluwer, Dordrecht, 2003 (a special issue of Mol. Diversity 2003, 7, pp 95–307);
Stadler, C. O. Kappe, Microwave-Assisted Organic Synthesis (Eds.: P. Lidstr_m, J. P. Tierney), Blackwell Publishing, Oxford, 2005 (Chapter 7).
Loupy (Ed.), Microwaves in Organic Synthesis, Wiley-VCH, Weinheim, 2002.
B. L. Hayes, Microwave Synthesis: Chemistry at the Speed of Light, CEM Publishing, Matthews, NC, 2002.
P. Lidstrom, J. P. Tierney (Eds.), Microwave- Assisted Organic Synthesis, Blackwell Publishing, Oxford, 2005.
For online resources on microwave-assisted organic synthesis (MAOS), see:

118. THANK
YOU
FOR YOUR ATTENTION!
118