carbon-carbon bond formation

• Nucleophilic substitution of haloalkanes with cyanide ions

  Change in functional group: haloalkane → nitrile
• Nucleophilic substitution of haloalkanes with cyanide ions

  1. Reagent: KCN dissolved in ethanol/water mixture

  2. Conditions: Heating under reflux

  3. Mechanism: Nucleophilic substitution

  4. Type of reagent: Nucleophile, :CN-
• Nucleophilic substitution of haloalkanes with cyanide ions

  • 1-bromopropane → butanenitrile
• Naming nitriles


  Nitrile groups have to be at the end of a chain. Start numbering the chain from the C in the CN
• Naming nitriles


  • CH3CH2CN: propanenitrile

  H3C-CH-CH2-C-N: 3-methylbutanenitrile

  H3C-C-H-CN: 2-methylpropanenitrile
• Addition of hydrogen cyanide to carbonyls to form hydroxynitriles


  Reaction: carbonyl → hydroxynitrile

  Reagent: sodium cyanide (NaCN) and dilute sulfuric acid

  Conditions: Room temperature and pressure

  Mechanism: nucleophilic addition
• Addition of hydrogen cyanide to carbonyls to form hydroxynitriles

  • CH3COCH3 + HCN → CH3C(OH)(CN)CH3 (2-hydroxy-2-methylpropanenitrile)

  CH3CHO + HCN → CH3CH(OH)CN (2-hydroxypropanenitrile)
• Nucleophilic Addition Mechanism


  NC-C-CH3-CH3-OH

  NC-C-CH3-H-OH
• Preparing amines from nitriles


  Reduce nitrile to amine by using LiAlH4 in ether or by reducing with H2 using a Ni catalyst
• Preparing amines from nitriles

  • CH3CH2CN + 4[H] → CH3CH2CH2NH2
• Preparing carboxylic acids from nitriles

  Hydrolysing nitriles by reacting them with strong acids will produce a carboxylic acid
• Preparing carboxylic acids from nitriles

  • CH3CH2CN + H+ + 2H2O → CH3CH2CO2H + NH4+
• Friedel Crafts Alkylation


  Change in functional group: benzene → alkylbenzene

  Reagents: chloroalkane in the presence of anhydrous aluminium chloride catalyst

  Conditions: heat under reflux

  Mechanism: Electrophilic substitution
• Friedel Crafts Alkylation


  • Any chloroalkane can be used RCl where R is any alkyl group Eg –CH3 , -C2H5.
• Formation of the electrophile in Friedel Crafts Alkylation

  AlCl3 + CH3CH2Cl → CH3CH2+ AlCl4-

  CH3CH2+ AlCl4- + AlCl3 + HCl
• Friedel Crafts Alkylation


  • CH2CH3
• Friedel Crafts Acylation


  Change in functional group: benzene → phenyl ketone

  Reagents: acyl chloride in the presence of anhydrous aluminium chloride catalyst

  Conditions: heat under reflux (50OC)

  Mechanism: Electrophilic substitution
• Formation of the electrophile in Friedel Crafts Acylation

  AlCl3 + CH3COCl → CH3CO+ AlCl4-

  CH3CO+ AlCl4- + AlCl3 + HCl
• Friedel Crafts Acylation


  • C-O-CH3