Answer to Question #38141 in Organic Chemistry for 123

Question

Hey!

I have a problem with understanding those mechanisms for organic compounds. I don't know how to differentiate between an electrophilic, nucleophilic and free radical reaction! They all sound so similar to me! And I don't know when and how every reaction starts out.

Can you please help me out with this?

Thanks.

Answer 1

Electrophilic reaction occurs when the electron-deficient particle (usually positively charged) attacks some standard electron-rich substrate. For example the nitration of benzene ring and the Friedel - Crafts reaction can be described as the aromatic electropfilic substitution.
Nucleophilic reaction takes place when the standard electron-deficient substrate (either positively charged on uncharged) is attacked by the electron-rich particle. The addition of methyllithium to ketones and the hydrolysis of chloroanhydrides are examples of nucleophilic reactions.
Generally the attribution of the reaction to nucleophilic or electrophilic mechanism depends on the substrate which we decided to appoint as the main one. Nevertheless this terms are popular in case of description of several similar processes.
The radical process unlike electrophilic and nucleophilic reactions usually take place in case of uncharged particles with unpaired electrons. Basically, the radical process occurs as the chain reaction, in which the one free radical (a particle with unpaired electron) enters the reaction, and the another free radical yields.