Substitution Vs Elimination Reaction

Contents

• Bimolecular reactions

• Nature of the substrate

• Temperature

• Nature of the reagents

• Solvents

Learning Objectives

At the end of this lecture, student will be able to

• Compare elimination and substitution reactions

• Relate the structure of alkyl halide with mechanism

Elimination vs Substitution Reaction

Bimolecular reactions

– Nature of the substrate

– Temperature

– Nature of the reagents

– Solvents

Unimolecular reactions

– Nature of the substrate

– Temperature

– Nature of the reagents

– Solvents

• Reactivity of alkyl halides towards substitution and elimination

• Effects of reaction variables on substitution and elimination reactions

Summary

• Elimination and substitution reactions involves attack by nucleophilic reagent

• Attack at carbon causes substitution, attack at hydrogen causes elimination

• Dehydration of alcohol involves heating alcohol with acid catalyst

• Tertiary alcohols - easiest to dehydrate, primary alcohols - hardest

• Major product is the more substituted alkene as given by Saytzeff rule