Study Set Content:
Electronegativities decrease in the order of:
F > Cl > Br > I
Carbon-halogen bond lengths increase in the order of:
C-F < C-Cl < C-Br < C-I
- Primary and secondary alcohols
- react much more slowly.
- Primary and secondary alcohols
- react much more slowly.
primary and secondary alcohols are treated with either
- thionyl chloride (SOCl2) or phosphorous tribromide (PBr3).
who discovered Grignard reagents
Victor Grignard
- Alkyl halides, RX, react with magnesium metal in ether solvent to yield alkyl magnesium halides, RMgX.
- Alkyl halides, RX, react with magnesium metal in ether solvent to yield alkyl magnesium halides, RMgX.
Grignard reagents (RMgX) are what type of compounds
- organometallic compound since it contains carbon–metal bonds.
don’t occur in living organisms, but they are useful carbon-based nucleophiles in important laboratory reactions
Grignard reagents
- also react with magnesium to give Grignard reagents.
alkyl halides, alkenyl (vinylic) and aryl (aromatic) halides
react with organohalides to yield coupled hydrocarbon products.
Gillman reagents:
Type of reaction alkyl halides undergo
Nucleophilic Substitution Reactions
Alkyl halides, if it reacts with nucleophile/electrophile (-OH), may undergo:
- substitution of the X group by the nucleophile
- elimination of HX to yield an alkene.
- Nucleophilic Substitution Reaction
- discovered by
Paul Walden
2 pathways:
- SN1 reaction
- SN2 reaction
- Bulky substrates react much more slowly than those in which the carbon is more accessible
- The Substrate
- The Nucleuphile
- any species that is either negative or neutral can act as a nucleuphile
- The Leaving Group
I-, Br-, or Cl- are the most common leaving group, although others are also possible. Anions such as F-, OH-, OR-, and NH2- are rarely found
- The Solvent
- polar aprotic solvents, meaning it DOES NOT contain -OH or -NH group are the best SN2 solvents
- kinetically a first-order reaction
SN1 reaction
- takes place only on tertiary substrates and only under neutral or acidic conditions in a hydroxylic solvent such as water or alcohol.
SN1 Reaction
