User:Benjah-bmm27/degree/2/CPB

Mechanism of a rearrangment reaction

Introduction

"Rearrangements involving Carbocationic or Polar Intermediates", Dr Craig Butts

Species

• Carbocations
• Carbon radicals (e.g. Ph₃C·)
• Carbenes
• Carbanions

Stereoelectronic effects

• Stereoelectronic effects
• Inductive effect
• Mesomeric effect (e.g. allyl, benzyl C⁺)
• Hyperconjugation, Beta-silicon effect
• Non-classical ions: norbornyl carbocations

Mechanisms

• Synchronicity of mechanisms: stepwise reaction, concerted reaction, reaction intermediate,
• Rearrangement reaction
• 1,2-rearrangement

Pinacol

• Pinacol rearrangement

Tiffeneau-Demjanov

• Tiffeneau-Demjanov rearrangement
  • Diazomethane variation

Wolff

• Wolff rearrangement

Demjanov

• Demjanov rearrangement

Wagner-Meerwein

• Wagner-Meerwein rearrangement
• nice animation

Arndt-Eistert

• Arndt-Eistert synthesis

Corey-Fuchs

• Corey-Fuchs reaction
  • converts aldehydes to alkynes, RCHO → RCCH
  • a special case of the Wittig reaction with Ph₃P=CBr₂, forms RHC=CBr₂, then BuLi and H₂O to RCCH

Hoffman

• Hofmann rearrangement

Curtius, Lossen, Schmidt

• Curtius rearrangement
• Lossen rearrangement
• Schmidt reaction

Beckmann

• Beckmann rearrangement
  • Caprolactam

Baeyer-Villiger

• Baeyer-Villiger oxidation

External links

• Animations of rearrangements from ChemTube 3d: http://www.chemtube3d.com/Rearrangements-Home.html
• Full notes: http://www.benjamin-mills.com/bristol/rearrangements/