Addition reaction of organic compounds in organic chemistry Electrophilic addition reaction Nucleophilic addition reaction Markonikov's addition Ozonolysis Polar addition reactions Non polar addition reactions Cycloaddition reactions Free radical addition Diels elder reaction Addition to alkynes Factors associated with alkenes

1. ADDITION REACTION
Represented By:Group 6
Saira-028,Maham,Kinza,Hafifa,Nida,Arooj-
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Represnted To: Ms. Uswa

2. Table of Content
Introduction
Types of Addition Reaction
Electrophilic Addition Reaction(Mechanism)
Nucleophilic Addition Reaction(Mechanism)
Markovnikov Rule
Ozonolysis of Alkenes(Mechanism)
Factors Associated with Alkenes
Reaction of Alkynes

3. INTRODUCTION
• Reactions which involve the combination of two reacting
molecules to give single molecule of product.
A+B C
(product)
• These are limited to chemical compounds with multiple
bonds.

4. • Alkenes mostly take part in addition reactions.
• The π-bond is broken and two new σ-bonds are formed.
• Alkenes are electron rich, with elctron density of π-bond
concentrated above and below.

5. • Addition reactions to alkenes and alkynes are sometimes
called saturation reactions.
• Addition reactions are the reverse of elimination reactions.

6. TYPES OF ADDITION REACTION

7. POLAR ADDITION REACTIONS
Electrophile Addition
• The process of adding an
electrophile to the pi bond
of an alkene.
• An electrophile forms a
sigma bond with a vinyl
carbon atom in double
bond.
Nucleophile Addition
• The process of adding a
nucleophile to either an
electron-deficient species
or pi bond in a molecule.
• A nucleophile forms a
sigma bond with a carbon
atom in the substrate.

8. Example of Electrophilic Example of Nucleophilic

9. NON POLAR ADDITION REACTION
Free Radical Addition
• The addition reaction which
involves free radical.
• The reaction occurs
between a radical and a
non-radical.
• It may involve two radicals.
• It is also known as radical
chain mechanism.
Cyclo Addition
• The reaction in which two
or more unsaturated
molecules combine.
• It forms a cyclic
adduct(cyclization).
• There is net reduction of
bond multiplicity.
• It permits carbon-carbon
without nucleophile or
electrophile.

10. Example of Free Radical Addition
Chlorination of
Methane
• A reaction between
methane and chlorine in
the prsence of UV light.
• A product of
chloromethane is
produced.
CH₄+Cl₂→CH₃Cl+HCl
Mechanism
1.Chain initiation:
Cl2 → 2Cl·
2.Chain propagation reactions :
CH4 + Cl·→CH·3+ HCl
CH·3 + Cl2→CH3Cl + Cl·
3.Chain termination reactions:
2Cl·→Cl2
CH·3 + Cl· → CH3C l

11. Example of
Cyclo
addition
Diels-Alder reaction
• A reaction between a conjugated
diene and a substituted
alkene(dienophile).
• A substituted cyclohexene
derivative is formed.

12. Electrophilic Addition
• The addition of an electrophile to a pi bond of an alkene.
• The carbon-carbon in an alkene is a region of high
electron density.
• This makes the C=C bond attractive to electrophiles.
• This is an electrophile addition reaction.
.

13. Mechanism
• It is a two step mechanism ,
Step 1:
• H-Br undergoes hetrolytic bond fission.
• The proton (H+) bonds with the caarbon atom of the C=C.
• A carbocation intermediate is formed.

14. Step 2:
• The anion uses a lone pair of electrons to form a bond
with the carbocation.
• The bromide ion forms a bond with the carbocation
producing bromoethane.

15. Nucleopilic Addition Reaction
• A nucleophile forms a single bond with an electron
defficient species.
• The conversion of carbonyl groups into variety of
functional groups.

16. Mechanism The electrophilic carbonyl
carbon forms a sigma bond
with the nucleophile.
The carbon-oxygen pi bond
is broken, forming an
alkoxide intermediate.
The subsequent protonation
of the alkoxide yields the
alcohol derivative.
Generally,
these
reactions are
broken down
into three
steps:

17. Addition of HCN
• Aldehydes and ketones undergo reaction with HCN to
produce cyanohydrins.
• The reaction progresses very slowly by using pure
hydrogen cyanide.
• The catalyst helps to speed up the reaction.
• As catalysis helps in the generation of cyanide ion (CN)
which acts as a stronger nucleophile.

18. MECHANISM
• The polar nature of the C=O bond makes the carbonyl
carbon electrophilic in nature.
• The CN¯ executes a nucleophilic attack on the carbonyl
carbon, resulting in the formation of an intermediate.
• This intermediate is now protonated to afford the
cyanohydrin product.

19. MARKOVNIKOV RULE
• Hydrogen is added to the carbon with the most hydrogens
and the halide is added to the carbon with least
hydrogens.
• the addition of hydrobromic acid (HBr) to propene;
• The majority of the products formed obey Markovnikov’s
rule, whereas the minority of the products do not.

20. Step 1:
• The alkene is protonated and it gives rise to the more
stable carbocation as
• Two types of carbocations that can be formed by
protonation,
Primary
Secondary(more stable and preferred)

21. Step 2:
• The halide ion nucleophile now attacks the carbocation.
• The reaction yields the alkyl halide.
• Rule was developed for its application in the addition
reaction of hydrogen halides to alkenes.
• The opposite to this is anti-Markovnikov rule.

22. Ozonolysis of Alkene
• Ozonolysis implies that ozone causes the alkene to break.
• a method of oxidatively cleaving alkenes using ozone
(O3), a reactive allotrope of oxygen.
• The process allows for carbon-carbon double or triple
bonds to be replaced by double bonds with oxygen.

23. Mechanism of Ozonolysis
• Step 1:
• The π electrons act as the
nucleophile, attacking the
ozone at the electrophilic
terminal O. A second C-O is
formed by the nucleophilic O
attacking the other end of
the C=C.

24. • Step 2:
The cyclic species called the
malozonide rearranges to the
ozonide.
• Step 3:
The ozonide decomposes
on work-up. Reductive work-
up with (usually Zn / acetic
acid) gives the two carbonyl
groups.

25. ADDITION REACTIONS OF ALKYNES
• The principal reaction of the alkynes is addition across
the triple bond to form alkanes.
• These addition reactions are analogous to those of the
alkenes.
HYDROGENTION
HALOGENATION
HYDROHALOGENATION
HYDRATION

26. Hydrogenation
• Alkynes undergo catalytic
hydrogenation with the some
catalyst(Pt, Pd, Lindlar’s
catalyst).
• In a stepwise manner an
alkenes is formed first and then
alkane.
Halogenation
• The addition of halogens to an
alkyne proceeds in the stepwise
manner.
• the formation of alkene, which
undergoes further reaction to a
tetrahaloalkane.

27. Hydrohalogenation
• Hydrogen halides react with
alkynes in the same manner as
they do with alkenes.
• Both steps in the above addition
follow the Markovnikov rule.
Hydration
• The addition of the elements of
water across the triple bond of
an alkyne leads to the formation
of aldehydes and ketones.
• terminal alkyne aldehyde
• non-terminal alkyne ketone

28. REFERENCES
1. Morrison, R. T.; Boyd, R. N. (1983). Organic
Chemistry(4th ed.). Boston: Allyn and Bacon.
2. March, Jerry; (1985). Advanced Organic Chemistry
reactions, mechanisms and structure (3rd ed.). New York:
John Wiley & Sons.
3. Fleming, Ian (2010). Molecular orbitals and organic chemical
reactions. New York: Wiley.
4. Myles W. Smith; Phil S. Baran (2015-08-28). "As simple as
[2+2]". Science 349 (6251): 925–926.
5. Hein, Sara M. (June 2006). "An Exploration of a
Photochemical Pericyclic Reaction Using NMR
Data". Journal of Chemical Education. 83 (6): 940–942.

29. THANK YOU