Substitution Nucleophilic Internal Reaction | Concept & Tricks | IIT Jee Mains, Advance | NEET скачать в хорошем качестве

Substitution Nucleophilic Internal Reaction | Concept & Tricks | IIT Jee Mains, Advance | NEET

SNi or Substitution Nucleophilic internal stands for a specific but not often encountered nucleophilic aliphatic substitution reaction mechanism. A typical representative organic reaction displaying this mechanism is the chlorination of alcohols with thionyl chloride, or the decomposition of alkyl chloroformates, the main feature is retention of stereochemical configuration. What happens here is that SOCl2 coordinates to the alcohol, with loss of HCl and formation of a good leaving group (“chlorosulfite”). The chlorosulfite leaving group can spontaneously depart, forming a carbocation, and when it does so, an “intimate ion pair” is formed, where the carbocation and negatively charged leaving group are held tightly together in space. From here, the chlorine can act as a nucleophile – attacking the carbocation on the same face from which it was expelled – and after expulsion of SO2, we have formation of an alkyl chloride with retention of configuration. We hope, You all will enjoy the Lecture. Team IITian Explains