Carbon-Carbon Bond Formation

What can be used in aliphatic compounds to form c-c bonds

Using cyanide ions as a nucleophile

• What reactions can c-c bonds be formed from in aliphatic compounds

• Nucleophilic substitution: Substitution of a halogen on a haloalkane by a CN group

• Nucleophilic addition: Addition of a CN group onto a carbonyl

Both of these reactions form nitriles

What reactions can c-c bonds be formed from in aromatic compounds

• Electrophilic substitution: Substitution of an alkyl group onto a benzene ring

• Electrophilic addition: Addition of an acyl group onto a benzene ring

Nucleophile

Electron pair donor

Nucleophilic substitution to form nitriles

• Reagent: KCN

• Nucleophile: CN^-

• Conditions: Dissolved in ethanol and heated under reflux

Nucleophilic addition to form hydroxy-nitriles

• Reagents - NaCN/HCl

• Nucleophile - CN^-

• Mechanism - Nucleophilic addition

Reaction of nitriles: Reduction to form amines

• Reduce a nitrile functional group with hydrogen gas and nickel catalyst

• General formula: RCN + 2H₂ → RCH₂NH₂

Reaction of nitriles: Hydrolysis of nitriles

• Forms a carboxylic acid in the presence of a dilute acid catalyst HCl(aq)

• CH₂CN + 2H₂O + HCl → CH₂COOH + NH₄Cl

Extending chain length in aromatic compounds: Alkylation - alkyl chain to an aromatic

• Reagents: Benzene + Haloalkane

• Catalyst: Halogen carrier

• Condition: Heat under reflux

• Mechanism: Electrophilic substitution

Extending chain length in aromatic compounds: Acylation - carbonyl to an aromatic

• Reactants: Benzene + acyl chloride

• Catalyst: Halogen carrier

• Condition: Heat under reflux

• Mechanism: Electrophilic substitution