Reactions of Aromatic Compounds Just like an alkene,benzene has clouds of it electrons above and below its sigma bond framework B-H attack on an electrophile sigma complex substituted 20PronEae,Ino Although the nt electrons are in a stable aromatic system,they are still available for reaction with strong electrophiles This generates a carbocation which is resonance stabilized(but not aromatic) igma comple (arenium ion) This cation is called a sigma complex because the electrophile is joined to the benzene ring through a new sigma bond. The sigma complex(also called an arenium ion)is not aromatic since it contains an sp'carbon (which disrupts the required loop of p orbitals). Chl7 Reactions of Aromatic Compounds (landscape).docx PagelCh17 Reactions of Aromatic Compounds (landscape).docx Page1 Reactions of Aromatic Compounds Just like an alkene, benzene has clouds of  electrons above and below its sigma bond framework. Although the  electrons are in a stable aromatic system, they are still available for reaction with strong electrophiles. This generates a carbocation which is resonance stabilized (but not aromatic). This cation is called a sigma complex because the electrophile is joined to the benzene ring through a new sigma bond. The sigma complex (also called an arenium ion) is not aromatic since it contains an sp3 carbon (which disrupts the required loop of p orbitals)