TRANSITION METAL CATALYSIS , THE DIFFERENT METALS OF TRANSITION USED AS CATALYTIC REAGENT WITH ITS PROPERTIES , THEIR CHARGE TRANSFER ITS REACTION INCLUDING COPPER, PALLADIUM FOLLWED BY HECKMAN, ULLMAN COUPLING REACTION, GILLMAN REACTION, HECK REACTION

2.  A transition metal as an element whose atom has a
partially filled d subshell, or which can give rise to
cations with an incomplete d sub-shell .
 The transition metal ions the outermost d orbitals are
incompletely filled with electrons so they can easily
give and take electrons. This makes transition metals
prime candidates for catalysis.
 Here transition metals are used as catalysts .

3. Zinc, cadmium, and mercury are generally excluded
from the transition metals as they have the electronic
configuration [ ]d 10s 2 , with no incomplete d shell.

4.  The formation of compounds in many oxidation states, due
to the relatively low energy gap between different
possible oxidation states eg, Fe(II), Fe(III) or switch
oxidizing state .
 Form complexes with reagents by adsorption at active site
.
 Colour in transition-series metal compounds is generally
due to electronic transitions of two principal
types.
 Charge transfer transitions
 d-d transitions

5. •Charge transfer transitions:
An electron may jump from a predominantly ligand orbital to a
predominantly metal orbital, giving rise to a ligand-to-metal
charge-transfer (LMCT) transition. These can most easily
occur when the metal is in a high oxidation state.
For example, The colour of chromate, dichromate and
permanganate ions is due to LMCT transitions.
Another example is that mercuric iodide, HgI2, is red because
of a LMCT transition .
•d-d transitions:
An electron jumps from one d-orbital to another d-orbital and
leads to d-d transitions .

6. The principal reasons why transition metals
contribute the essential ingredient in catalyst
systems can be summarized as the following
headings:
(a) Bonding ability
(b) Catholic choice of ligands
(c) Ligand effects
(d) Variability of oxidation state
(e) Variablility of co-ordination number

7. Sr.no Transition metal Type of reaction
1 Rhodiam Wilkinson’s reaction
2 Copper 1. Gilman reaction
2. Ullman Coupling Reaction
3. Reactions of organo copper
reagent
3 Palladium 1. Heck Reaction
2. Negishi Reaction
3. Stille Reaction
4. Buchwalt-Hartwig amination
5. Suzuki Reaction
6. Sonogashira reaction
7. Hiyama coupling Reaction
4 Nickel Kumada coupling Reaction

8. It is used in the selective hydrogenation of alkenes
and alkynes without affecting the functional groups
like: C=O, CN, NO2, Aryl, CO2R etc.

9.  A Gilman reagent is a lithium and copper
(diorganocopper) reagent compound, R2CuLi (Lithium
dimethylcuprate), where R is an alkyl or aryl.
 They react with organic halides to replace the halide
group with an R group . Such displacement reactions
allow for the synthesis of complex products from simple
building blocks

10.  Generalized chemical reaction showing Gilman reagent
reacting with organic halide to form products and showing
Cu(III) reaction intermediate
 In the reaction, the Gilman reagent is a methylating reagent
reacting with an alkyne in a conjugate addition forming a
cyclic enone

11.  Ullmann coupling is a coupling reaction between
aryl halides in the presence of copper as a transition
metal catalyst to produce Diaryl compounds .
 A typical example is the coupling of 2 ortho-
chloronitrobenzene reactants to form 2,2'-
dinitrobiphenyl with a copper - bronze alloy .

12.  Carbocupration is a nucleophilic addition of organocopper
reagents (R-Cu) to acetylene or terminal alkynes resulting in
an alkenylcopper compound (RC=C-Cu).It is a special case of
carbometalation and also called the Normant reaction.
A. Substitution Reactions
 oxidative addition of copper(I) into the carbon-leaving
group bond takes place, generating a copper(III)
intermediate which then undergoes reductive elimination
to generate the coupled product .

13. B.Conjugated addition reaction
 Carbocupration across the carbon-carbon double bond may then
generate a copper enolate, Subsequent reductive elimination and
protonation leads to the product.
C. Enantioselective Variants
 Diastereoselective conjugate addition reactions of chiral
organocuprates provideβ-functionalized ketones in high
yield and diastereoselectivity

14.  It is the chemical reaction of an alkyl halide with
an alkene in the presence of a base and a
palladium catalyst (or palladium nanomaterial-
based catalyst) to form a substituted alkene .

15.  The reaction couples alkyl or aryl halides with
organozinc/tin compounds, forming carbon-carbon bonds
(c-c) in the process.
• It involves the coupling of an organotin compound (also
known as organostannanes) with a variety of organic
electrophiles via palladium catalyzed coupling reaction .

16.  Used for the synthesis of carbon–nitrogen bonds
via the palladium catalyzed cross-coupling of
amines with aryl halides .
In this coupling occurs between a boronic acid and an
organohalide which is catalyzed by a palladium(0)
complex .

17. The Sonogashira reaction is a cross-coupling reaction used in
organic synthesis to form carbon–carbon bonds. It employs
a palladium catalyst to form a carbon–carbon bond between
a terminal alkyne and an aryl or vinyl halide .
The Hiyama coupling is a palladium-catalyzed cross-coupling
reaction of organosilanes with organic halides used in organic
chemistry to form carbon–carbon bonds (C-C bonds) .

18.  The Kumada coupling is a type of cross coupling
reaction, useful for generating carbon–carbon
bonds by the reaction of a Grignardreagent and an
organic halide.
 The procedure uses transition metal catalysts,
typically nickel orpalladium, to couple a
combination of two alkyl, aryl or vinyl groups

19.  www.wikipeadia.com
 Textbook of organic chemistry by morrisons and boyd
seventh edition pg no 350
 Textbook of Organic chemistry by Arun bahl and B.S.
bahl Pg no 356