Course Details
Subject {L-T-P / C} : CY5107 : Pericyclic Reactions and Photochemistry { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Prof. Niranjan Panda
Syllabus
Pericyclic reactions: Electrocyclic Reaction: Molecular orbitals and symmetry operations, Aromatic transition state approach (Huckel and Mobius systems), Woodward-Hoffmann rule, correlation diagrams, Frontier orbital theory. Electrocyclic reactions: Thermal and photochemical electrocyclic processes. Electrocyclic reactions of cations, anions, radicals and radicals ions, Nazarov cyclization, ring opening of aziridines Cycloaddition reactions: [4+2] cycloaddition reactions, nature of diene Orbital description,, dienophile, stereochemistry of product. Regioselectivity in Diels-Alder reactions, endo selectivity. Intramolecular Diels-Alder reaction. Retro-Diels-Alder reaction. Genaration and reactions of quinodimethanes, benzofurans. Photochemical and thermal [2+2]-cycloaddition reaction, Ketene cycloaddition, Alder ‘Ene Reaction’ Transition metal-catalyzed cycloadditions. 1,3-Dipolar cycloadditions application to heterocycle synthesis (Huisgen reaction, “Click” reaction). Cheletropic reactions. Sigmatropic reactions: Orbital description, [1,3], [1,5], [1,7], [2,3], [3,3] and [5,5] sigmatropic shifts, theory and reactions. Cope rearrangement, Oxy-cope rearrangement, Claisen rearrangement, Abnormal-claisen rearrangement, variants of Claisen rearrangement.
Photochemically driven organic reactions: Principles and concepts, Jablonski diagram and photophysical processes, Franck-Condon principle. Reactions: Photochemistry of alkene, di-pi-methane rearrangement. Photochemistry of carbonyl compounds, Norrish type-I and type-II reactions, Paterno-Buchi reaction, photochemistry of enone and dienones. Barton reaction, photo oxidation and reduction, photo-Fries rearrangement.
Course Objectives
- To understand concerted reactions specifically types and principles of pericyclic reactions
- Conservation of orbital symmetry and how reaction conditions control the mode of bond formation
- What are Electrocyclic, cycloaddition and sigmatropic reactions, and stereochemistry f the product.
Course Outcomes
1) This course offers an understanding of how some organic molecules react with each other under thermal and photochemical conditions in a single step to give important molecules. <br />2) The students will have the understanding of the reactivity of different reagents leading to organic transformations.
Essential Reading
- . R. B. Woodward and R. Hoffmann, The Conservation of Orbital Symmetry, Academic Press, New York
- M. Smith, Organic Synthesis, Mc Graw Hill
Supplementary Reading
- R. P. Wayne, Principles and Applications of Photochemistry, Oxford Science Publications, Oxford University Press, Oxford
- M. J. S. Dewar and R. C. Dougherty, The PMO Theory of Organic Chemistry, Plenum Press, New York