Bhavya
Last Activity: 9 Years ago
The Wurtz reaction is an organic reaction used to couple two alkyl halides to form an alkane using sodium metal. The mechanism begins with a single electron transfer (SET) from sodium metal to the alkyl halide, which dissociates to form an alkyl radical and sodium halide salt. Another molecule of sodium performs another SET to the alkyl radical to form a nucleophilic carbanion. The carbanion then attacks another molecule of alkyl halide in a nucleophilic substitution reaction (SN2) to form the final coupled product and another molecule of sodium halide salt.
One electron from the metal is transferred to the halogen to produce a metal halide and an alkyl radical.
R–X + M → R• + M+X−
The alkyl radical then accepts an electron from another metal atom to form an alkyl anion and the metal becomes cationic. This intermediate has been isolated in several cases.
R• + M → R−M+
The nucleophilic carbon of the alkyl anion then displaces the halide in anSN2 reaction, forming a new carbon-carbon covalent bond.
R−M++ R–X → R–R + M+X−
Using two different alkyl halides will lead to an approximately statistical mixture of products.If two dissimilaralkyl halidesare taken as reactants, then the product is a mixture of alkanes that is often difficult to separate as the difference in the boiling points of the products is very low in these cases, making distillation unusable.
