This module completes the work in begun in year 1, to provide a coherent mechanistic overview of all of the key organic functional groups and their formation/reactivity.

Knowledge and Understanding

1. Describe mechanisms for commonly encountered reactions of carbonyl compounds.
2. Understand the molecular structure of carbonyl compounds and relate this to their reactivity under a range of reaction conditions.
3. Appreciate the distinction between kinetically and thermodynamically controlled reactions.
4. Understand the reasons for the stability of aromatic organic compounds, and be able to relate this to the types of reaction that such compounds undergo.
5. Describe the mechanisms of electrophilic aromatic substitution reactions with a range of common reagents.
6. Predict the site of electrophilic attack on monosubstituted and polysubstituted aromatic compounds.
7. Rationalise the relative rates of electrophilic substitution reactions of substituted aromatic compounds.
8. Describe the outcome and mechanisms of addition reactions of alkenes.
9. Understand the fundamental differences between the reactivity of alkenes and aromatic systems.
10. Describe the mechanisms of reactions used for the formation and functionalisation of heteroaromatic compounds.

Intellectual Skills

1. Apply fundamental principles of organic reactivity to predict and rationalise the outcome of organic chemical reactions.
2. Use mechanistic reasoning based on known reaction pathways to deduce the likely mechanisms of unknown, but similar, reactions.
3. Relate the structures of aromatic organic compounds to their spectroscopic (primarily NMR) data and use this understanding to rationalise the electrophilic substitution reactions of such compounds.
4. Analyse molecular structures and devise strategies for the preparation of organic compounds using reactions covered in this course.

Practical Skills

Prepare and purify organic compounds using a range of reaction types, synthetic methods and purification techniques.

The module will consist of 33 x 1 hour lectures, 27 (5 x 3 + 3 x 4) hours of practical, 14 (7 x 2 hour) problem-based workshops (2 x carbonyl chemistry, 2 x aromatic chemistry, 1 x alkene chemistry, 2 x heterocyclic chemistry) and 4 x 1 hour tutorials.

Chemistry-specific skills are highly focused on the area of mechanistic organic chemistry, and centre on the fundamental relationship between molecular structure and reaction mechanism. Students will develop a detailed understanding of reaction mechanisms and be able to rationalise and deduce mechanistic pathways based on fundamental principles. This area is a specific type of problem-solving; however, the rigorous structured approach to solving problems of this type will be transferrable to other types of problem solving.

A written exam (3 h) will test the student’s knowledge and understanding as elaborated under the learning outcomes. The coursework (workshops and tutorials) will allow the student to demonstrate his/her ability to judge and critically review relevant information.  Practical skills will be assessed via a series of laboratory-based exercises.

Chemistry of the carbonyl group (11L)

Addition reactions to aldehydes and ketones.

Formation of acetals, ketals, imines and enamines, relating the reactions to S_N1 reactions seen in year 1.

Modern aspects of imine/enamine chemistry – iminium ion organocatalysis.

Carboxylic acids and esters: applications, biological importance, mechanisms for ester formation/hydrolysis, emphasising the importance of acidity/basicity in determining the course of the reaction.

Enols and enolates, aldol and Claisen condensations and related reactions.

Kinetic and thermodynamic enolates.

Conjugate addition to alpha,beta-unsaturated carbonyl compounds. Organocuprates and malonate-type nucleophiles. Hard and soft nucleophiles.

Aromaticity (8L)

Stability and molecular orbitals of aromatic systems.

Electrophilic substitution reactions of benzenoid aromatic compounds. Directing effects of substituents, resonance forms.

Relationship between the reactivity and spectroscopy of aromatic systems.

Alkenes (4L)

Electrophilic addition reactions to alkenes. Hydroboration, epoxidation.

Comparison of the addition reactions of alkenes with substitution reactions of benzene.

Aromatic Heterocyclic Chemistry (10L)

Synthesis of aromatic heterocyclic systems – pyridine, pyrimidine, pyrrole, furan, oxazole, thiazole, focusing on the fundamental nature of the reactions involved.

Nucleophilic and electrophilic substitution of aromatic heterocyclic systems.

Lithiation chemistry for the functionalisation of heterocyclic aromatic compounds.

Organic Chemistry, 5^th Edition, G. M. Loudon, Roberts and Company Publishing, 2009.

Please see Essential Reading List.