Definition: What is Suzuki Reaction?

A coupling reaction in organic chemistry is a general term for a variety of reactions where two fragments are joined together with the aid of a metal catalyst. The Suzuki reaction, or Suzuki-Miyaura coupling reaction, is an organic coupling reaction of an organohalide with an organoborane to give a coupled product using a palladium catalyst and base. Boronic acid or boronic ester, or exceptional cases of aryl boron trifluoride can be used as well. This reaction is used to create carbon-carbon bonds to produce conjugated systems of alkenes, styrenes, or biaryl compounds ^[1-5].

The history of this reaction goes back to 1979 when Japanese Nobel Laurate Akira Suzuki first published this work in a scientific journal.

Examples of Suzuki Reaction

Examples of Suzuki reaction include aryl, alkenyl (vinyl), and alkynyl halides reacting with aryl, alkenyl (vinyl), or alkynyl organoborane ^[2-7].

Mechanism of Suzuki Reaction

The Suzuki coupling mechanism follows a catalytic cycle involving three primary steps. These are oxidative addition, transmetalation, and reductive elimination. The first step is the oxidative addition of aryl halides to the Pd⁽⁰⁾ complex to give intermediate 1, a Pd⁽²⁾ species. Under the action of a base, an organoborane compound reacts with intermediate 1 in transmetalation to give intermediate 2. This step is followed by reductive elimination to give the desired product and regenerate the original Pd⁽⁰⁾ species ^[2-8].

Applications of Suzuki Reaction

Suzuki reaction can conjoin a variety of aryl halides and alkenyl halides with alkenylboranes and arylboronic acids and is thus an essential method of synthesizing many styrenes, alkenes, and biphenyls. It is very cost-effective for use in the synthesis of intermediates for pharmaceuticals or fine chemicals.