The Suzuki reaction is a palladium-catalyzed cross-coupling process that combines boronic acids and organohalides to form carbon-carbon bonds, crucial for organic synthesis. Developed by Akira Suzuki in 1979, the reaction consists of three primary steps: oxidative addition, trans metalation, and reductive elimination. This method is favored for its mild conditions, safety, and ability to produce a variety of compounds, including styrenes and biphenyls.

1. Suzuki Reaction and its
Mechanism
Hajira Mahmood
Ph.D. CHEMISTRY

2. Suzuki Reaction
It is an organic reaction, classified as a cross-coupling reaction, where the
coupling partners are a boronic acid and an organohalide. The catalyst being
used is a palladium complex.
• The Suzuki Reaction is an important type of coupling reaction, a designation
that encompasses a variety of processes that combine (or “couple”) two
hydrocarbon fragments with the aid of a catalyst.
• The reaction can conjoin a variety of aryl halides and alkenyl
halides with alkenyl boranes and aryl boronic acids.
• Commonly referred to as the Suzuki cross-coupling
• An important method of synthesizing many styrene, alkenes, and biphenyls.

3. Akira Suzuki
Japanese chemist
 Nobel Prize in 2010
first published the Suzuki reaction, the organic reaction of an aryl- or
vinyl-boronic acid with an aryl- or vinyl-halide catalyzed by a
palladium complex, Reported in 1979 by Akira Suzuki and N. Miyaura.

4. Mechanism of Suzuki Reaction
• Palladium catalyzed cross-coupling reactions, between an organic
halide and an organometallic reagent, that forge carbon-carbon bonds
constitute one of the central pillars of modern-day organic synthesis.
• Three sequential mechanistic events define the general catalytic cycle
1. oxidative addition of the organic halide to palladium (0) to form a
palladium (II) complex
• 2. trans metalation i.e. transfer of the organic portion of the
organometallic reagent to the palladium (II) center.
• 3. reductive elimination to form the new carbon-carbon bond and
regenerate palladium (0) catalyst.

5. Mechanism of Suzuki Reaction

6. Oxidative Addition
• The rate determining step of the catalytic cycle
• Couples the palladium catalyst to the alkyl halide which gives rise to
the organopalladium complex
• The complex is initially in the cis conformation but isomerizes to the
trans conformation
• Stereochemistry with vinyl halides are retained but inversion of
stereochemistry occurs with allylic or benzylic halide

7. Trans metalation
 The role of base is to activate the boron-containing reagent, and
facilitate the formation of R1PdOR from R1Pd-X.
 Reaction does not occur in the absence of base.

8. Reductive Elimination
 This final step gives the desired product and it also regenerates the
palladium catalyst so that it can participate again in the catalytic cycle
(I.e. making more products).
 Require the complex to revert to the cis conformation before reductive
elimination can occur

9. Merits
 Mild Reaction Conditions
 Availability of common boronic acids
 Inorganic by-products are easily removed from reaction
mixture.
 Stereoselective
 Less toxic than other competitive methods, (ie. Boronic
acids are environmentally safer and less toxic than
organostannanes)
 Reaction will take place in the presence of other
functional groups (ie. protecting group is not always
necessary)
 Relatively cheap reagents, easy to prepare, and GREEN!