Reaciton Of Arenes Flashcards
What type of reaction do they undergo? Not full
Substitution
Why do they undergo the reaction they do?
Substitution keeps the delocalized electron structure making it stable
What type of reaction do they undergo (full)
Electrophilic substitution
What’s the general equation for electrophilic substitution reaction?
R-X + E+ –> R-E + X+
R is aryl group
E is Electrophiles
X is leaving group
What is an Electrophile?
A positive ion or molecule with a partial positive charged localized on one of the atoms that will be attracted to a negatively charged region. React by accepting a pair of electrons and forming a covalent bond
Nitration –> reactions and conditions and what’s the Electrophiles
Benzene + Concentrated sulfuric acid and concentrated nitric acid.
Below 55 degrees Celsius
Electrophiles - NO2 +
Sulfonation R/C and Electrophiles
Benzene + conc sulfuric acid heat under reflux several hours
Electrophiles - SO3 +
Chloronation
Benzene + chlorine + anhydrous aluminum chloride.
Room temp
Electrophiles - Cl+
Bromination
Benzene + bromine + anhydrous iron (III) bromide or iron filings room Temp
Electrophiles - Br+
Alkylation
Benzene + chloroalkane + anhydrous aluminum chloride
Heat under reflux
Electrophiles - ch3 ch2+ (alcl4-)
Acylation
Benzene + Acyl chloride + anhydrous aluminum chloride
Heat under reflux
Electrophiles- ch3co+ (alcl4-)
What are Friedan reactions
Alkylation
Acylation
Why are Friedan craft reactions good
Add carbon side chains to benzene rings which can then be modified further
Where can Friedan crafts reactions be Carried out?
In ionic liquids as combination solvent -catalyst systems
Why are solvent -catalyst systems good
Reduce solvent emissions, reduce flammability , often recycle easily and allow reactions to occur at lower temperatures
