Skip to main content
Chemistry LibreTexts

15.1: An overview of the different types of electrophilic reactions

  • Page ID
    994
  • [ "article:topic", "Lower Division", "Organic", "Author tag:Soderberg", "authorname:soderberg", "authorname:soderbergt", "showtoc:no" ]

    • Contributed by

    Electrophilic reactions all involve essentially the same first step: pi electrons attack an electrophile or a proton, forming a carbocation intermediate.  Nucleophilic attack by pi electrons on an tetrahedral carbon electrophile can occur in an SN1-like or SN2-like fashion, and pi bonds can also attack carbonyl carbons in what is essentially an electrophilic variation on the carbonyl addition (chapter 11) mechanism.

    image012.png

     

    image016.png

    In many cases, a nucleophile next adds to the carbocation intermediate. The result is electrophilic addition (of Nu + E or Nu + H) to the double bond.

    image020.png

    In an electrophilic addition/elimination mechanism, the double bond is preserved. Nucleophilic attack by the pi electrons (addition) is followed by proton abstraction adjacent to the carbocation, leading to re-formation of a double bond (elimination).

    image024.png

    If the pi bond in question is part of an aromatic system, the reaction is referred to as an electrophilic aromatic substitution

    image028.png

     

    Contributors