Oxidation of organic compounds by d block metals

1. A
Seminar Report
On
OXIDATION OF ORGANIC
COMPOUNDS BY d-BLOCK METALS
Submitted By
Naman Mehrotra
M.SC II sem.IV
Roll no.- 17045010923, Batch(2016-2018)
Submitted To-
Department of Chemistry
Lucknow Christian Degree College
Lucknow

2. Acknowledgement
I w o u l d l i ke to ex p r e s s my s p e c i a l t h a n k s o f g r a t i t u d e
to my te a c h e r D r. A b h a s A st h a n a a s w e l l a s o u r h e a d o f
d e p a r t m e nt D r. Re n u G u pta w h o g a v e m e t h e g o l d e n
o p p o r t u n i t y to d o t h i s w o n d e r f u l p r o j e c t o n t h e to p i c
“ OXIDATION OF ORGANIC COMPOUNDS BY d-BLOCK METALS”, w h i c h
a l s o h e l p e d m e i n d o i n g a l o t o f Re s e a r c h a n d I c a m e to
k n o w a b o u t s o m a ny n ew t h i n g s I a m r e a l l y t h a n k f u l to
t h e m .
S e c o n d l y I w o u l d a l s o l i ke to t h a n k my pa r e nt s a n d
f r i e n d s w h o h e l p e d m e a l o t i n f i n a l i z i n g t h i s p r o j e c t
w i t h i n t h e l i m i te d t i m e f r a m e .
Naman Mehrotra
M.sc 2nd year
IVth semester

3. Contents
 INTRODUCTION
 Use of Manganese (Mn) as oxidizing agent
 Use of Chromium (Cr VI) as oxidizing agent
 Use of Osmium (Os) as oxidizing agent
 Use of Ruthenium (Ru) as oxidizing agent
 Use of Silver (Ag) as oxidizing agent

4. Introduction
 Oxidation for the Organic Compound is the addition or
gain of oxygen or removal of hydrogen.
 There are many oxidizing agent of d block element
which are used to convert primary alcohol to aldehyde
(ex-CrO3,Ag2CO3), 1o alcohols to carboxylic acid ex-
KMnO4,2o Alcohols to ketone(ex-Na2Cr2O7,MnO2),
nitro compounds to aldehyde or ketones by alkaline
KMnO4,Aromatic Hydrocarbons to diones by CrO3
,alkene to diols by OsO4 etc.
 During oxidation metal reduce to its lower stable
oxidation state.

6. Use of Manganese (Mn) as oxidizing agent
• Mn in both +4 and +7 oxidation state use as a
oxidizing agent.
• Mn (IV) is mild oxidizing agent and selective oxidizing
agent. It is specific for Benzylic alcohol and allylic
alcohol to aldehyde and takes place under mild
condition (room temperature) in neutral solvent
(H2O, Benzene, CHCl3, Acetone, ether etc).It convert
1o alcohol to 2o alcohol to carbonyl compounds.
Carbon-Carbon multiple bond are unaffected by this
reagent.

8. •Manganese dioxide has also been used to
convert conjugated aldehyde to conjugated
ester in presence of nitrile group.

9. Mechanism of MnO2

10. Oxidation with KMnO4
• Potassium Permanganate, a derivative of hypervalent
manganese is a very powerful oxidizing agent. Its
reactivity depends on whether it used in acid, neutral or
basic medium. In acid solution Mn(VII) reduce to divalent
Mn(II) with a net transfer of five electron. However in
neutral or basic medium manganese dioxide is usually
formed corresponding to a three-electron change
(Mn(VII) to Mn(IV).
• It is also well known that the yield in KMnO4 is
considerably improved by the use of phase transfer
catalyst (PTC).

11. Oxidation of alcohol By KMnO4
• Primary and secondary alcohol are oxidized to
carboxylic acid and ketones, respectively, containing
the same number of carbon atoms.

12. Oxidation of alkenes
• Alkenes on treatment with dilute KMnO4 solution in
presence of alkali give 1,2-diols. In this reaction, the
purple KMnO4 is reduced to MnO2 a brown solid. The
change in colour is the basis of the test for the
presence of double or triple bond known as the
Baeyer test for unsaturation.

14. Oxidation of Alkynes by KMnO4
• Alkynes undergo oxidation with KMnO4 to give diketo
acid in neutral condition. If oxidation is carried out in
acidic medium mixture of two acids is obtain.

15. Oxidation of Aromatic side chain
and aromatic ring system
• Benzene ring is not effected by oxidizing agent due to
used as solvent. Alkyl group present in benzene
nucleus the side chain oxidize to carboxylic acid.
• Benzene ring can be cleaved if it is used to
heterocyclic system.

18. Oxidation of Nitro Compounds
• Alkaline KMnO4 oxidizes primary and secondary nitro
compounds into corresponding carbonyl compounds.

20. Use of Chromium (Cr VI) as oxidizing
agent
• CrO3, Jones oxidant, PCC or PDC, Collins reagent, Chromyl
chloride are widely use oxidizing agent in Cr.
• Reactivity & selectivity depends on
• (1) Solvents
• (2) Chromium ligands
• The most widely employed transition metal oxidations are
Cr(VI) based reagents.

21. Oxidation with CrO3+H2SO4 (JONES
REAGENT)
• Oxidation of primary alcohol with Jones Reagent may
result in the conversion of the aldehyde initially
formed to the corresponding carboxylic acid.

22. • Jones Reagent used for the oxidation of primary and
secondary alcohols and does not effect any group
present in the compound.

23. Oxidation of 3o alcohol with Jones Reagent
• Generally 3o alcohol is usually inert to oxidation with
H2CrO4 as they don’t have α-hydrogen. But 3o 1,2-
diol undergo rapid C-C single bond cleavage by this
reagent forming ketones cis 1,2-diol give ketone.

25. Oxidation of Hydroquinone, Para hydroxyl aniline, benzene
1,4 diamine with Jones reagent
• Para hydroxyl aniline, benzene 1, 4 diamine treated
with Jones reagent to give benzoquinone.

26. Mechanism

27. Oxidation with CrO3+py+CH2Cl2
(Collins-Ratcliffe Reagent)
• Collin reagent is mild reagent for the
oxidation of alcohols that contain acid
sensitive groups. Collin’s reagent
prepared by adding CrO3 to a mixture of
pyridine- CH2Cl2.

28. Oxidation with CrO2Cl2 + CCl4
• CrO2Cl2 + CCl4 is generally a mild oxidizing
agent it convert methyl group attach to
benzene ring into formyl group in
presence of strong acid or with a solution
of CrO2Cl2 in CCl4 of CS2 (Etard Reaction).

29. Chromium Based Oxidation
R OH R CHO
OH
R R'
O
R R'
R OH R COOH
Transformation
PCC, Collins reagent,
PDC in DCM
PCC, Collins reagent,
PDC, Jones reagent
Jones reagent, PDC
in DMFCHO
Etard reaction
Chromium Reagents

30. Use of Osmium (Os) as oxidizing agent
Oxidation with OsO4
• The addition of an alkenes to osmium teraoxide in ether
cause rapid precipitation of cyclic osmate ester. Pyridine
which complexes the osmium atom in the ester, is often
added as catalyst. The ester is then hydrolyzed, commonly
with aq. Sodium sulphite to give cis-vis diols. It is a
classical example of steriospecific oxidation.

31. • OsO4 is both highly poisonous and expensive, but is very
reliable and valuable reagent because of its specificity
with the double bonds and the ease of its application. It is
found that 5mole% osmium teraoxide is sufficient to
oxidize alkenes if a steriometric amount of N-
methylmorpholine-N-oxide (NMO) is used.
• NMO in the reaction reoxidises the osmium (VI) to
Os(VIII) insitu, thus a very small amount of osmium
teraoxide is needed for the oxidation.

33. • Due to electrophilic nature the presence of
electron withdrawing groups to the alkenes
double bond retards the hydroxylation. Thus if
more than one double bond are present then
hydroxylation occur at more electron rich
double bond.

34. Lemieux-Johnson Reagent (OsO4/ NaIO4)
• When OsO4 is used in the combination with
NaIO4(sodium periodate)it is known as Lemieux-
Johnson Reagent and it give the same product as in
ozonolysis product. OsO4 in catalytic amount react
with double bond to give an osmate ester, which
then decompose in the presence of NaIO4 to give
cleavage products of the diols along with
regenerated OsO4.

35. Use of Ruthenium (Ru) as oxidizing agent
Oxidation with RuO4
• Ruthenium teraoxide is a powerful
oxidizing agent which oxidizes variety of
functional groups at room temperature.
• Oxidation with RuO4 is generally carried
out in CCl4, CH3CN solution. Since RuO4 is
costly so it is convenient to use catalytic
amount of RuO4 in presence of NaIO4
which oxidizes the reduced Ru back to
active teraoxide in situ.

36. RuO4 cleaves the C-C double bond give ketone and carboxylic acids.

37. • Alcohol also oxidized by this reagent,
primary alcohol gives carboxylic acid and
secondary alcohol are oxidized to ketone
in excellent yield at room temperature.
The reagent has no effect on ester and
epoxide group.

38. Use of Silver (Ag) as oxidizing agent
Ag2CO3 on Celite (Fetizon’s Reagent)
• An excellent reagent for oxidizing primary
alcohol and secondary alcohols to aldehyde and
ketones under mild and essential neutral
condition is silver carbonate precipitated on
celite.
• Other function group in substrate is unaffected.
Highly hindered group are not attacked, allowing
selective oxidation.
• Primary alcohol are oxidized more slowly than
secondary which are much less reactive than
Benzylic and allylic alcohol.

39. Order of Reactivity