Organic Chemistry 2

Overview

Staff: Contribution:
Dr. K. Tchabanenko Module Co-ordinator, 6 lectures, 1 seminar on Reagents for C-C Bond Formation, Lab supervisor, Workshop facilitator, Class Test examiner.
Dr. P. Knipe 6 lectures, 1 seminar on Alicyclic Chemistry, 6 Lectures on Stereochemistry, Lab supervisor, Workshop facilitator, Class Test examiner.
Dr. K. Tchabanenko 6 lectures, 1 seminar on Reactive Intermediates, Lab supervisor, Workshop facilitator, Class Test examiner.
Dr. G. Sheldrake 6 lectures, 1 seminar on Heterocyclic Chemistry, Lab supervisor, Workshop facilitator.
Dr. J. Vyle 6 lectures,1 seminar on Primary metabolites.



Summary of Lecture Content:

1. Reagents for C-C Bond Formation
Lecturer: Dr. K. Tchabanenko E-mail address: k.tchabanenko@qub.ac.uk
6 Lectures

Detailed synopsis:

Carbon-electrophiles and carbon-nucleophiles. Relative acidities of CH bonds and bases. Organo-magnesium, lithium, zinc and copper reagents as C-nucleophiles: formation, structure and reactivity. Malonates, enolates, enamines and reactions thereof. Decarboxylation of -ketoacids.
Wittig reaction. Chemoselectivity and protecting groups. Role of Lewis acids in organic chemistry.



2. Alicyclic Chemistry
Lecturer: Dr P Knipe E-mail address: p.knipe@qub.ac.uk
6 Lectures, 1 seminar

Detailed synopsis:

This course describes the structures of carbon-based ring systems. Ring strain will be used to rationalize the conformational preferences of these molecules. The thermodynamics and kinetics of ring formation as a function of ring size will be discussed. Baldwin’s Rules governing kinetically-controlled ring-closing reactions will be introduced. Where relevant, frontier molecular orbitals (FMOs) will be used as a tool to explain conformation and reactivity.

Key strategies for the synthesis of cyclic compounds:
(i) Cyclization reactions – to include intramolecular alkylation (SN2-like) of enolates; Dieckmann condensation; Robinson ring annulation; ring-closing metathesis.
(ii) Cycloadditions reactions – to include carbene insertion e.g. Simmons-Smith (cyclopropanes); [2+2]-photocycloaddition (cyclobutenes); Diels-Alder [4+2] cycloaddition (cyclohexenes).
(iii) Ring expansion and contraction reactions – to include Favorskii, Wolff and Tiffeneau-Demjanov rearrangements.





3. Reactive Intermediates
Lecturer: Dr. K.Tchabanenko E-mail address: k.tchabanenko@qub.ac.uk
6 Lectures

Detailed synopsis:
Radicals
Reintroduction to radicals, homolytic bond strengths and cleavage, radical stabilities, radical precursors, initiators and acceptors, nucleophilic and electrophilic radicals, chain reactions, halogenations, cyclisations, rearrangements, substitutions, aromatic radical chemistry, oxidations, deoxygenations and reductions, hydrogen abstractions.
Carbenes and Nitrenes
Structure (singlet vs. triplet), stability, synthesis, N-heterocyclic carbenes, cyclopropanation, aziridination, C-H insertion, benzoin and Stetter reactions, rearrangements, ring expansions, reactions of dichlorocarbene, uses in synthesis.

4. Natural products: The Primary Metabolites
Lecturer: Dr. J. Vyle E-mail address: j.vyle@qub.ac.uk
6 Lectures and 1 workshop.

Detailed synopsis:
• Introduction to primary metabolites (1 lecture)
Understand biological relevance of each class of compound; know basic structures of monomers and polymers; D- / L- and - / -descriptors.
• Carbohydrate chemistry (2 lectures)
Selective hydroxyl-group protection / activation; chemical glycosylation strategies,
/-anomeric control.
• Nucleoside chemistry (2 lectures)
Preparation of nucleosides with modified and unmodified sugars, nucleobases, phosphate esters.
• Amino acid chemistry (1 lecture)
Selective protection of side-chain functional groups and -amines.




5. Heterocyclic Chemistry
Lecturer: Dr. G. Sheldrake E-mail address: g.sheldrake@qub.ac.uk
6 Lectures, 1 seminar

Detailed synopsis:
This course introduces the properties, chemistry and synthesis of aromatic heterocyclic compounds. Material will include:
• six-membered heterocycles: pyridine and derivatives; quinolines and isoquinolines. Structure, aromaticity and preparation. Amine reactions. Electrophilic and nucleophilic substitution. Oxidation and reduction, substituted pyridines and substituent reactivity.
• five-membered ring heterocycles: pyrrole, thiophene, furan and derivatives. Indole. Structure and reactivity. Electrophilic and nucleophilic substitution.
• rings containing more than one heteroatom: pyrimidine and purine: natural occurrence and importance in biology. Imidazoles, oxazoles, thiazoles, triazoles, tetrazoles: reactivity and applications in synthesis.

Coursework assignments:

1. NMR Spectroscopy Workshop
Facilitators: Dr. G. Sheldrake, Dr. K. Tchabanenko, Dr. P. Knipe
Two 3-hour workshops

Please note that these workshops will take place on the first or second day of term and are compulsory.

These workshops are designed to teach the principles of NMR spectroscopic interpretation which is a fundamental skill in organic chemistry and will be required many times in organic and inorganic practicals and Level 3 / Level 4 projects. The course will provide an introduction to an NMR spectroscopic software package (Bruker TopSpin) which enables the user to determine the parameters of a spectrum and extract data such as chemical shift, integration and coupling constants. Working in small groups (2-3) you will be given NMR spectra of some simple organic compounds along with some basic rules and guidelines and asked to identify the structures from the spectra.

2. Class Test
Set and marked by: Dr. K. Tchabanenko and Dr. P. Knipe
1 hour during Week 9

There will be a Class Test in Week 9 of the semester which will test your knowledge and understanding of the first three lecture courses. This is an important and compulsory element of the coursework and contributes 5% towards the overall module mark.

3. Practical Experiments
Lab Supervisors: Dr. G. Sheldrake, Dr. P. Knipe Dr. K. Tchabanenko

Organic Chemistry is a practical subject and this course of six experiments is designed to teach many of the key skills required for synthetic organic chemistry, such as chromatography, distillation, crystallisation, spectroscopic characterisation, as well as providing practical examples of some of the important reactions encountered in the lecture material. The course will also provide practice in preparing experimental reports in the correct chemistry literature styles.

Full details of the practical programme will be provided in the CHM2003 Laboratory Manual.

4. Tutorials
Tutors: members of the Organic Teaching Staff
Five 1-hour tutorials, fortnightly from Week 4 (plus revision tutorial if requested)

The lecture material will be supported by small group (≤ 6) tutorials held in weeks 4, 7, 9, 10 and 12. The tutorials will be structured around questions from a tutorial booklet, circulated at the beginning of term, but these sessions are also an opportunity to discuss aspects of the course material that are causing problems or are difficult to assimilate.

Full details of the tutorial programme will be provided in the CHM2003 Tutorial Booklet.

Learning Objectives

Learning outcomes:
Upon completion of the module the student will have:
* An understanding of chemical terminology, nomenclature and conventions, to be achieved through the recognition and application of reagents e.g. electrophiles/ nucleophiles, carbocations, carbanions, radicals, carbenes and nitrenes.
* Some appreciation of new types of chemical reactions in the context of reagents for carbon carbon bond formation, cyclisation reactions, condensation reactions and ologosaccaride formation.
* An ability to compare and contrast the distinctive structural and electronic features of the main classes of heterocyclic compounds.
* A knowledge of the principal synthetic methods for preparing heterocycles and examples of reactions typical of each class.
* A knowledge of the chemical structure of primary metabolites including sugars, oligosaccharides and nucleotides, the key reactions used for their formation.
* Direct experience of the practical application of key reagents, reactions and analytical techniques in synthetic organic chemistry e.g. organometallic reagents, C-C bond formation reactions, cyclisations, chromatographic separation and spectroscopic analysis.

Skills

Learners are expected to demonstrate the following on completion of the module:
Subject specific skills will have been acquired by the students. The practical skills will be improved via longer and substantially more complex experiments, and more rigorously assessed reports (compared to the first year module). In addition, students will have acquired skills in experimental reporting in the correct style for peer-reviewed journals.

Assessment

Assessment:
Examination 60 %
Class Test 5%
Practical 30 %
Tutorials 5 %


Course Requirements:
Practical attendance at 100 %,
Practical report submission 100%,
Class test attendance at 100 %
Both Coursework and Examination must be passed at 40 %