Faculty of Biotechnology
Organic Chemistry
Chapter 5
Dr. Mohamed Abd-Elhakeem
It is a fact organic synthesis change our
recent life. Each one use at least one
synthetic product every day
But the price was very high
Synthesis industry introduces
contaminants into a natural
environment that causes
instability, disorder of brain,
harm the ecosystem i.e.
components of pollution, can
be either foreign substances
or energies
World need a safe chemicals.
Need environmentally friendly
chemistry
Need Green Chemistry
Green
chemistry,
is
the
design
of
chemical products and processes that
reduce or eliminate the use or generation
of hazardous substances.
The
Green Chemistry program
supports the invention of more
environmentally friendly
1- chemical processes
2- Chemicals
This
program works very closely with
the twelve principles
of Green
Chemistry.
 Prevent
Waste Design chemical syntheses to
prevent waste, leaving no waste behind to clean
up or treat.
 Maximize
Atom Economy Design syntheses
so that the final product incorporates the
maximum amount of raw material used to
create it, leaving few or no atoms behind.
 Design
Less Hazardous Chemical Syntheses
Design syntheses to use and generate
substances with little or no toxicity to human
health or the environment whenever possible.
 Create
Safer Chemicals Design chemical products
to be fully effective while minimizing or
eliminating toxicity.
 Use
Safer Solvents and Auxiliaries Create
processes that utilize innocuous auxiliary substances
(such as water and eco-friendly materials) as
solvents or separation agents. Otherwise, avoid
using auxiliaries at all.
 Design
for Energy Efficiency Conduct chemical
processes at ambient temperature and pressure
whenever possible.
 Use
Renewable Feedstock Utilize renewable raw
materials and feedstock whenever technically and
economically practical, rather than depleting nonrenewable materials.
 Reduce
Derivatives Minimize or avoid the use of
blocking or protecting groups and avoid making
temporary modifications when possible. Derivatives
require additional reagents and generate waste.
 Use
Catalysts Instead of Reagents Minimize waste
by using catalytic reactions that use small amounts of
materials.
 Design
for Degradation Design chemical products
that break down at the end of their use and do no
persist in the environment.
 Prevent Pollution in Real Time Make real-time, inprocess monitoring, analysis and control part of your
process to minimize or eliminate the formation of
hazardous byproducts.
 Minimize
the Potential for Accidents Design
chemicals and their forms (such as liquid, solid or
gas) in such a way as they minimize the potential for
chemical accidents including explosions, fires and
toxic releases into the environment.
Classic Route to Ibuprofen
H C l, AcO H , Al W aste
Ac 2 O
Ac O H
HCl
H 2 O / H+
C lC H 2 C O 2 Et
AlC l 3
Na OEt
C O C H3
Et O 2 C
O HC
O
N H2 O H
H 2 O / H+
N
H O2C
N H3
OHN
Hoechst Route To Ibuprofen
AcOH
HF
H2 / Ni
CO, Pd
Ac2O
O
HO
HO2C
Biocatalysis
Biocatalysis is the use of enzymes as catalysts
to
perform
chemical
organic compounds.
transformations
on
Biocatalysis underpins some of the oldest chemical
transformations known to humans,
The oldest records of brewing are about 6000 years old
and refer to the Sumerians.
The employment of enzymes and whole cells have been
important for many industries for centuries. The most
obvious uses have been in the food and drink businesses
where the production of wine, beer, cheese and yogurt.

More than one hundred years ago, biocatalysis was
employed to do chemical transformations on nonnatural man-made organic compounds

the last 30 years have seen a substantial increase in the
application of biocatalysts to produce fine chemicals,
especially for the pharmaceutical industry.
Organic
chemistry
Biochemistry
Biocatalysis
Microbiology
Molecular
biology
I- Selectivity/Specificity
Substrate selectivity – ability to distinguish a
particular compound from among a mixture of
chemically related compounds.
1-Chemo selectivity: Functional group selectivity –
ability to act on one functional group selective even
when other groups may be more chemically reactive
2- Regio selectivity: distinguish between
functional groups which are chemically
situated in different regions of the
substrate molecule.
3- Stereo selectivity – ability to act on a
substrate or produce a product of one
Enantiomeric or diastereomeric form
II. Mild reaction conditions – most enzymes
operate in aqueous solution, at mild
temperatures and pH’s, and at
atmospheric pressure. While
Chemical catalysts often require organic
solvents, high temperatures, extremes of
pH and high pressure. Enzymes can
therefore result in lower energy and
materials cost.
III. Environmentally friendly, ie, “green
chemistry”
proteins are naturally
biodegradable, aqueous solution avoids
solvent waste, lower energy costs = lower
emissions
IV. High catalytic efficiency high turnover
numbers, ie, substrate molecules catalyzed
per molecule of enzyme, resulting in less
catalyst required to complete the
conversion
 1.
Oxidoreductase (dehydrogenase) Catalyze
redox reactions, usually NAD is used as a
coenzyme
 2.
Transferases (acylase, phosphorylase)
Catalyze transfer of a molecular group from one
molecule to another
 3.
Hydrolases (esterase, lipase) Catalyze bond
cleavage by the introduction of water
 4.
Lyases!(a.k.a synthase - decarboxylase)
Cleavage of C-Y (C or heteroatom) bonds to
form double bonds or rings (or reverse rxn.)
 5.
Isomerases (racemase, epimerase)
Catalyze reactions involving intramolecular
rearrangements
 6.
Ligases (a.k.a. synthetase - DNA ligase)
Formation or cleavage of C-Y (C or
heteroatom) bonds with triphosphate (ATP)
hydrolysis
Class
Name
function
importance in
organic synthesis
1
Oxidoreductases
Oxidations and reductions
High
2
Transferases
Transfer of functional groups
Low
3
Hydrolases
Hydrolysis and condensation
reactions
Very high
4
Lyases
Addition of small molecules to
double bonds and elimination
Reactions
Medium
5
Isomerases
Isomerization reactions
Low
6
Ligases
Formation of covalent bonds
Low
 The
high value of hydrolase enzymes is due
to
 1- Their stability at different pH
 2- they can be used in organic solvents
 3- they don’t need cofactors from the cell