The aim of the module is to extend second year knowledge of synthetic and physical organic chemistry.

(LO1) Students will have a good understanding of some core synthetic reactions.

(LO2) Students will be able to apply their knowledge to solve problems involving these reactions

(LO3) Students will be able to deduce mechanisms on the basis of kinetic and other evidence

(LO4) Students will be able to solve simple retrosynthetic problems involving Y3 chemistry

Lectures: 30 x 1 hr lectures.

Workshops: 4 x 2 hr workshops, formative, problems available in advance, solutions after.

Class Test. 1 hr test, mid semester.

*Lectures: 30 hours
*Workshops: 8 hours

Rearrangements and Fragmentations
Essential 1,2-migration reactions: Baeyer-Villiger, Beckmann, Curtius, Hoffmann, Wagner-Meerwein, and (semi)pinacol reactions.
Ionic fragmentation reactions: Grob and Favorskii reactions

Pericyclic reactions
Essential features of orbital overlap (Woodward-Hoffmann and Fukui analyses of orbital overlap)
Sigmatropic rearrangements: 1,n-hydride and alkyl shift, [3.3] sigmatropic rearrangement
Cycloaddition reactions: Diels-Alder [4+2] cycloaddition, 1,3-dipolar cycloadditions, [2+2] cycloadditions.
Electrocyclic reactions for ring opening and ring closing.

Radical reactions
Radical reactions follow different rules to those of ionic reactions. Bond strength is very important. Radicals can be formed with Br, Cl, Sn, and Hg. Efficient radical reactions are chain reactions. There are electrophilic and nucleophilic radicals. Radicals favour conjugate addition. Cyclization is easy with radical r eactions. Dissolving metal reductions with metal-ammonia systems applied to aromatic systems (Birch reduction) and enones and their synthetic applications. Dissolving metal reductions applied to carbonyl groups - Pinacol coupling and acyloin condensation.

Organophosporous, organsulfur, and organoselenium chemistry
Phosphorus: Wittig, Wittig-Horner and Wadsworth-Emmons reactions and their use in synthesis. Aza-Wittig reaction. Mitsunobu reaction, mechanism and applications.
Sulfur: Introduction to organosulfur compounds (oxidation states, names etc.). Synthesis and chemistry of sulfoxides, allylic sulfoxide-sulfenic ester rearrangement. Pummerer reaction, syn elimination of sulfoxides. Sulfones - Julia reaction, Ramberg Backlund reaction and extrusion of SO2 from sulfolenes. Chemistry of sulfur ylids, Corey/Trost reagents.
Selenium: Comparison of sulfur and selenium compounds. Reactions of selenoxides, syn elimination and [2,3] sigmatropic rearrangements. Oxidat ion reactions of selenium dioxide. Selenium mediated cyclisation reactions (PhSeCl etc.).

Physical organic chemistry
Energy diagrams: Intermediates and transition states, K = k1/k-1, Hammond’s postulate, thermodynamic vs kinetic control, Curtin-Hammett.
Kinetics: Revision of elementary kinetics, steady state for multistep reactions, primary deuterium kinetic isotope effect., Hammet equation.
Energy diagrams and kinetics for SN2, SN1, E1, E2, E1cb, mechanistic continuum, HX, X2 additions.
Nucleophilic substitution at carbonyls: Tetrahedral intermediates and mechanisms for ester hydrolysis.
Baldwin’s rules

Palladium-catalysed coupling reactions.
Introduction, Buchwald-Hartwig, Suzuki, Miyaura, Heck, Sonogashira.