1 / 17

More on: Molecular Orbitals Pericyclic Reactions Electrocyclic Reactions

More on: Molecular Orbitals Pericyclic Reactions Electrocyclic Reactions. y. x. z. mirror in yz plane. Pi Bonding MO (bond along x-axis; orbitals in xy plane). S ymmetrical mirror plane (yz). y. x. z. rotate 180 o about z-axis in xy-plane. Pi Bonding MO

howardjacobs
Download Presentation

More on: Molecular Orbitals Pericyclic Reactions Electrocyclic Reactions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. More on: Molecular Orbitals Pericyclic Reactions Electrocyclic Reactions

  2. y x z mirror in yz plane Pi Bonding MO (bond along x-axis; orbitals in xy plane) Symmetrical mirror plane (yz)

  3. y x z rotate 180o about z-axis in xy-plane Pi Bonding MO (bond along x-axis; orbitals in xy plane)

  4. y x z Pi Bonding MO (bond along x-axis; orbitals in xy plane) Antisymmetric about the C2 axis

  5. y x z mirror in yz plane Pi Antibonding MO (bond along x-axis; orbitals in xy plane) Antisymmetric mirror plane (yz)

  6. y x z rotate 180o about z-axis in xy-plane Pi Bonding MO (bond along x-axis; orbitals in xy plane) Symmetric about C2 axis

  7. Bonding Mirror C2 - axis Antibonding node Pi Bond MO A S S A

  8. anti-bonding - p3* 2 nodes SA Energy of an isolated p-orbital non-bonding - p2 1 node AS SA bonding - p1 0 nodes Allylic Resonance allyl radical allyl cation allyl anion

  9. AS anti-bonding M.O. - p4* Energy of isolated p-atomic orbital (A.O.) anti-bonding M.O. - p3* LUMO SA bonding M.O. - p2 HOMO AS SA bonding M.O. - p1 M.O.s of 1,3-Butadiene Lowest Unoccupied Molecular Orbital Highest Occupied Molecular Orbital

  10. AS AS SA SA AS SA Orbital Symmetry in the Diels-Alder Reaction LUMO HOMO Equal HOMO-LUMO Energy Difference

  11. AS AS SA SA AS EWG EWG SA Diels-Alder Reaction with a Deactivated Dienophile LUMO HOMO EWG Lowers LUMO Energy

  12. EWG EWG The Diels-Alder Reaction Transition State Diene HOMO (p2) Dienophile LUMO (p3*)

  13. hn DE Photochemical Excitation in 1,3-Butadiene HOMO photochemical rxn. HOMO thermal rxn.

  14. 1,3-Butadiene Cyclobutene Disrotatory p3* hn Conrotatory p2

  15. but one cyclobutene is just like another cyclobutene enter stereochemistry

  16. 1,3-Butadiene Cyclobutene Me Disrotatory Me Me Me p3* H H hn Me H Conrotatory Me H H Me p2 H Me

  17. trans E,E E,Z cis Stereocontrol in the 1,3-Diene Cyclization hn Dis Thermal Con Thermal Con hn Dis

More Related