Este documento aborda las reacciones de adición, que implican la combinación de dos moléculas para formar un solo producto, especialmente en compuestos con enlaces múltiples como alquenos y alquinos. Se describen varios tipos de reacciones de adición, incluyendo la adición electrofílica y nucleofílica, así como las reglas de Markovnikov y el ozonólisis de alquenos. Además, se analizan los mecanismos de estas reacciones y sus aplicaciones en la química orgánica.

1. ADDITION REACTION
Represented By:Group 6
Saira-028,Maham,Kinza,Hafifa,Nida,Arooj-
066
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