Green Chemistry Applications

• Green chemistry, also called sustainable chemistry,
is an area of chemistry and chemical engineering
focused on the designing of products and processes
that minimize the use and generation of hazardous
substances. Whereas environmental
chemistry focuses on the effects
of polluting chemicals on nature, green chemistry
focuses on technological approaches to
preventing pollution and reducing consumption of
nonrenewable resources
3/29/2018 2Green Chemistry Applications

• In 1998, Paul Anastas (who then
directed the Green Chemistry
Program at the US EPA) and John
C. Warner (then of Polaroid
Corporation) published a set of
principles to guide the practice of
green chemistry.[10] The twelve
principles address a range of ways
to reduce the environmental and
health impacts of chemical
production, and also indicate
research priorities for the
development of green chemistry
technologies.

• Developed by Paul Anastas and John Warner*
Prevention
It is better to prevent waste than to treat or clean up waste after it has been created.
Atom Economy
Synthetic methods should be designed to maximize the incorporation of all
materials used in the process into the final product.
Less Hazardous Chemical Syntheses
Wherever practicable, synthetic methods should be designed to use and generate
substances that possess little or no toxicity to human health and the environment.
Designing Safer Chemicals
Chemical products should be designed to affect their desired function while
minimizing their toxicity.
Safer Solvents and Auxiliaries
The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be
made unnecessary wherever possible and innocuous when used.

Design for Energy Efficiency
Energy requirements of chemical processes should be recognized for
their environmental and economic impacts and should be minimized. If
possible, synthetic methods should be conducted at ambient temperature
and pressure.
Use of Renewable Feedstocks
A raw material or feedstock should be renewable rather than depleting
whenever technically and economically practicable.
Reduce Derivatives
Unnecessary derivatization (use of blocking groups, protection/
deprotection, temporary modification of physical/chemical processes)
should be minimized or avoided if possible, because such steps require
additional reagents and can generate waste.
Catalysis
Catalytic reagents (as selective as possible) are superior to stoichiometric
reagents.

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.
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.
Inherently Safer Chemistry for Accident Prevention
Substances and the form of a substance used in a chemical
process should be chosen to minimize the potential for
chemical accidents, including releases, explosions, and fires.

• A dry media reaction or solid-state reaction or solventless
reaction is a chemical reaction system in the absence of a
solvent.1 The drive for the development of dry media
reactions in chemistry is: · Economics (save money on
solvent) · Not required to remove a solvent after reaction
completion ultimetly purification step not required · Reaction
rate is high due more avaibility of reactants · Environmentaly
friendly because solvent is not required · Some of the
drawbacks are: · Homogenous reactants should mix to a
system · Viscosity high in reaction sysyem · Unsuitable for
solvent assisted chemical reactions

• As originally defined by Arthur Michael, the reaction is the
addition of an enolate of a ketone or aldehyde to an α,β-
unsaturated carbonyl compound at the β carbon. A newer
definition, proposed by Kohler,is the 1,4-addition of a doubly
stabilized carbon nucleophile to an α,β-unsaturated carbonyl
compound.

• Aziridines are organic compounds containing
the aziridine functional group, a three-
membered heterocycle with one amine
group (-NH-) and two methylene bridges (-CH
2-).[5][6] The parent compound is aziridine (or
ethylene imine),

• Eco-friendly direct solvent-free synthesis of
flavones is achieved by microwave irradiation
of phloroglucinol and β-ketoesters. Heating
with microwaves versus under classical
conditions was shown to be higher yielding,
cleaner, and faster. The reaction goes through
a cycloaddition of an α-oxo ketene
intermediate followed by an uncatalyzed
thermal Fries rearrangement.

• aqueous phase The water portion of a system
consisting of two liquid phases, one that is
primarily water and a second that is a liquid
immiscible with water.

• Microwave chemistry is the science of applying microwave radiation to
chemical reactions. Microwaves act as high frequency electric fields and
will generally heat any material containing mobile electric charges, such as
polar molecules in a solvent or conducting ions in a solid.
Polar solvents are heated as their component molecules are forced to
rotate with the field and lose energy in collisions. Semiconducting and
conducting samples heat when ions or electrons within them form
an electric current and energy is lost due to the electrical resistance of the
material. Microwave heating in the laboratory began to gain wide
acceptance following papers in 1986,[although the use of microwave
heating in chemical modification can be traced back to the 1950s.
Although occasionally known by such acronyms as MAOS (Microwave-
Assisted Organic Synthesis),MEC(Microwave-Enhanced Chemistry)
or MORE synthesis (Microwave-organic Reaction Enhancement), these
acronyms have had little acceptance outside a small number of groups.

• By the use of thess method is easy to carryout
reactions with out using solvents

• In the alkaline hydrolysis of esters and amides the
hydroxide ion nucleophile attacks the carbonyl carbon in
a nucleophilic acyl substitution reaction. This mechanism is
supported by isotope labeling experiments. For example,
when ethyl propionate with an oxygen-18 labeled ethoxy
group is treated with sodium hydroxide (NaOH), the
oxygen-18 is completely absent from the sodium
propionate product and is found exclusively in
the ethanol formed.

• By the use of thess method is easy to carryout
reactions in water
•

• In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the migration of a
reactant from one phase into another phase where reaction occurs. Phase-transfer
catalysis is a special form of heterogeneous catalysis. Ionic reactants are often soluble in
an aqueous phase but insoluble in an organic phase in the absence of the phase-transfer
catalyst. The catalyst functions like a detergent for solubilizing the salts into the organic
phase. Phase-transfer catalysis refers to the acceleration of the reaction upon the addition
of the phase-transfer catalyst.
• By using a PTC process, one can achieve faster reactions, obtain higher conversions or
yields, make fewer byproducts, eliminate the need for expensive or dangerous solvents
that will dissolve all the reactants in one phase, eliminate the need for expensive raw
materials and/or minimize waste problems. Phase-transfer catalysts are especially useful
in green chemistry — by allowing the use of water, the need for organic solvents is
reduced.[1][2]
• Contrary to common perception, PTC is not limited to systems
with hydrophilic and hydrophobic reactants. PTC is sometimes employed in liquid/solid and
liquid/gas reactions. As the name implies, one or more of the reactants are transported
into a second phase which contains both reactants.
•

• Ultrasound is sound
waves with frequencies higher
than the upper audible limit of
human hearing. Ultrasound is no
different from 'normal' (audible)
sound in its physical properties,
except in that humans cannot
hear it. This limit varies from
person to person and is
approximately
20 kilohertz (20,000 hertz) in
healthy, young adults. Ultrasound
devices operate with frequencies
from 20 kHz up to several
gigahertz .

• Regular achiral organocatalysts are based on nitrogen such
as piperidine used in the Knoevenagel condensation.[11] DMAP used
in esterfications and DABCO used in the Baylis-Hillman
reaction. Thiazolium salts are employed in the Stetter reaction. These
catalysts and reactions have a long history but current interest in
organocatalysis is focused on asymmetric catalysis with chiral catalysts,
called asymmetric organocatalysis or enantioselective organocatalysis. A
pioneering reaction developed in the 1970s is called the Hajos–Parrish–
Eder–Sauer–Wiechert reaction. Between 1968 and 1997, there were only
a few reports of the use of small organic molecules as catalysts for
asymmetric reactions (the Hajos–Parrish reaction probably being the most
famous), but these chemical studies were viewed more as unique
chemical reactions than as integral parts of a larger, interconnected field.[1
• 2]

• An ionic liquid (IL) is a salt in the liquid state. In some contexts, the
term has been restricted to salts whose melting point is below
some arbitrary temperature, such as 100 °C (212 °F). While ordinary
liquids such as water and gasoline are predominantly made
of electrically neutral molecules, ionic liquids are largely made
of ions and short-lived ion pairs. These substances are variously
called liquid electrolytes, ionic melts, ionic fluids, fused
salts, liquid salts, or ionic glasses. They are known as "solvents of
the future" as well as "designer solvents".

Acknowledgement of SEMINAR
I have taken efforts in this project. However, it would
not have been possible without the kind support and
help of many individuals and organizations. I would
like to extend my sincere thanks to
DR.V.JAGADESWER
I would like to express my gratitude towards my
parents & member of ( UNIVERSITY COLLEGE OF
SCIENCE SAUFABAD CHEMISTRY )for their kind
co-operation and encouragement which help me in
completion of this SEMINAR

Green Chemistry Applications

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Green Chemistry Applications