Grignard Reagent

We are discussing Grignard Reagents in class. A Grignard Reagent is an alkyl- or aryl- magnesium halide that acts as a nucleophile and attacks electrophilic carbon atoms that are present within polar bonds to yield a carbon-carbon bond. Below shows the reaction used to make 4-nonylbenzoic acid:

  

 The Grignard Reagent is used in step A. The addition of the nonylmagnesium bromide causes an immediate color change from red to black-violet. The final product of that reaction is 4-Nonylbenzoic acid methy ester. The Grignard reagent is highlighted below:

A Grignard reaction yields new C-C bonds. There were 8 new C-C bonds formed in Step A. They are highlighted below:

The group performing this experiment developed an alternative method for alkyl-(hetero)aryl- as well as aryl-heteroaryl cross coupling reactions catalyzed by iron salts. They discovered that the expensive noble metal catalysts can be replaced by cheap, air stable, commercially available and toxicaologically benign salts without any loss in efficiency. The reactions are usually carried out under "ligand free" conditions using inexpensive Grignard reagents as the preferred coupling partners. They also found due to the efficiency with which the iron catalysts activate the C-Cl bond, several functional groups are tolerated that normally would react with a Grignard reagent. Feel free to read more by clicking on the source listed below! :)

Source:
http://orgsyn.org/orgsyn/default.asp?formgroup=basenpe_form_group&dataaction=db&dbname=orgsyn