extending carbon chain

• Has to exist with polar carbon
• uses cyanide
• cyanide is C triple bond N
• its mechanism is nucleophilic substitution where cyanide acts as a nucleophile
• the carbon in cyanide is negatively charged
• cyanide can be sourced from NaCN, HCN and KCN
• Reaction with cyanide ions conditions:

  warm ethanolic potassium cyanide under reflux
• halogenoalkanes + CN → nitriles
• halogenoalkane has a polar bond
• Potassium cyanide reacts with carbonyl compounds to produce hydroxynitriles
• Hydroxynitriles includes OH and CN
• Carbonyl compounds contain C=O
• HCN or acidified KCN is used
• Nitriles can be formed by reacting haloalkanes with sodium cyanide, NaCN, or potassium cyanide, KCN, in ethanol
• Nitriles from aldehydes and ketones

  Aldehydes and ketones will react with hydrogen cyanide in a nucleophilic addition reaction. The reaction forms a carbon-carbon bond, thus increasing the number of carbon atoms in the molecule.
• Hydrogen cyanide is far too poisonous to use, and an increased reaction rate can be obtained in the presence of cyanide ions.

  A mixture of sodium cyanide and sulfuric acid is used, which improves safety and increases reaction rate.
• Nitriles are useful intermediates in the synthesis of other organic compounds such as amines and carboxylic acids.
• Nitriles can be reduced to amines by reacting with hydrogen in the presence of a nickel catalyst.
• Nitriles undergo hydrolysis to form carboxylic acids by heating with dilute aqueous acid, for example, HCl (aq)
• Forming carbon-carbon bonds to benzene rings

  Alkylation is a reaction that transfers an alkyl group from a haloalkane to a benzene ring. The reaction takes place in the presence of a Friedel-Crafts catalyst such as aluminium chloride.
• Acylation

  When benzene reacts with an acyl chloride in the presence of an aluminium chloride (AlCl3) catalyst, a ketone is formed. This reaction is known as acylation. This reaction is useful in synthesis as the organic product undergoes the typical reactions of a ketone.
• Compounds that contain a carbon-metal bond are known as organometallic compounds
• Organometallic compounds are very important for forming C-C bonds in organic compounds to increase the length of a carbon chain
• Organometallic compounds containing Mg or Li are often used for to extend carbon chains
• An organometallic compound provides a source of a nucleophile called a carbanion, which contain a carbon atom with a negative charge
• The carbanion reacts with a positively charged or &+ carbon atom to form a new C-C bond