Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They...

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Pericyclic Reaction

Transcript of Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They...

Page 1: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Pericyclic Reaction

Page 2: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

ψ1

HOMO

ψ5

LUMO

ψ2

ψ3

ψ4

ψ1

ψ5

ψ2

ψ3

ψ4

No of conjugated p orbitals (np) = 5No of π-molecular orbitals = 5

npis odd, nBMO = (np-1)/2 = 2nAMO = (np-1)/2 = 2nNMO = 1

Pericyclic Reactions: π-Molecular Orbital

Page 3: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Indicate the following as BMO, AMO or NBO

Pericyclic Reactions: π-Molecular Orbital

I II

IVIII

Order of energy: I>II>III>IV

Page 4: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Pericyclic Reactions: Reactivity

Page 5: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Based on FMO theory, predict whether the following reaction is feasible or not

Pericyclic Reactions: Reactivity

Page 6: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Based on FMO theory, predict whether the following reaction is feasible or not

Pericyclic Reactions: Reactivity

Page 7: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

worked at the University of Kiel anddiscovered this reaction in 1928. Theywon the Nobel Prize in 1950.

Otto Diels (1876–1954) Kurt Alder (1902–58)

Diene Dienophile

Pericyclic Reactions: Selectivity of Diels-Alder Reaction

Page 8: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Geometry of dienophile retained

Pericyclic Reactions: Selectivity in Diels-Alder Reaction

HOMO (ψ2) LUMO (ψ2)

Only Cis-product

Page 9: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Geometry of dienophile is retained: cis-alkene give cis-product and trans-alkene gives trans-product

Pericyclic Reactions: Selectivity in Diels-Alder Reaction

Page 10: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Pericyclic Reactions: Selectivity in Diels-Alder Reaction

Page 11: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Why HOMO of diene interact with the LUMO of Dienophile?

Pericyclic Reactions: Selectivity of Diels-Alder Reaction

Page 12: Pericyclic Reaction · worked at the University of Kiel and discovered this reaction in 1928. They won the Nobel Prize in 1950. Otto Diels (1876–1954) Kurt Alder (1902–58) Diene

Looking forward

Pericyclic Reaction:Reactivity and Selectivity of electrocyclic reactionPericyclic Reactions in Biological Systems

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