ORG CHEM RXNS

Hydrohalogenation

Adds HX across a double bond.

Hydrohalogenation rxn

C=C + HBr → C-C

Hydrohalogenation Reagents

HCl, HBr, HI

Hydrohalogenation Regiochemistry

Markovnikov addition

Hydrohalogenation other factors

Carbocation intermediate, Rearrangements possible

Hydrohalogenation with Peroxides

Adds HBr in the presence of ROOR.

Hydrohalogenation with Peroxides RXN

C=C + HBr → C-C-Br (anti-mark)

Hydrohalogenation with Peroxides Reagents

HBr, ROOR

Hydrohalogenation with Peroxides Regiochemistry

Anti-Markovnikov

Hydrohalogenation with Peroxides Other

Radical mechanism, No carbocation rearrangements

Halogenation

Adds two halogens

Halogenation RXN

C=C + Br2 → Br-C-C-Br

Halogenation Reagents

Br₂ or Cl₂

Halogenation stereochemistry

Anti addition

Halogenation Other

Bromonium ion intermediate

Halohydrin Formation

Adds a halogen and an OH.

Halohydrin Formation RXN

C=C + Br2, H2O → Br-C-C-OH

Halohydrin Formation Reagents

Br₂/H₂O or Cl₂/H₂O

Halohydrin Formation Stereochemistry

Anti addition

Halohydrin Formation Regiochemistry

Markovnikov's rule

Haloether Formation

Adds a halogen and an OR group.

Haloether Formation RXN

C=C + Br2, EtOH → Br-C-C-OEt

Haloether Formation Stereochemistry

Anti addition

Haloether Formation Regiochemistry

Markovnikov addition (OH on more substituted carbon)

Hydration (Acid-Catalyzed)

Adds H and OH.

Hydration (Acid-Catalyzed) RXN

C=C + H2O → C-C

Hydration (Acid-Catalyzed) Reagents

H₃O⁺

Hydration (Acid-Catalyzed) Regiochemistry

Markovnikov addition

Hydration (Acid-Catalyzed) Other

Carbocation intermediate, Rearrangements possible

Hydroboration-Oxidation

Adds H and OH.

Hydroboration-Oxidation Reagents

1) BH3·THF

2) H2O2, NaOH

Hydroboration-Oxidation Regiochemistry

Anti-Markovnikov

Hydroboration-Oxidation Stereochemistry

Syn addition

Hydroboration-Oxidation

Often forms racemic mixtures when stereocenters are created

Catalytic Hydrogenation

Adds H₂.

Catalytic Hydrogenation Reagents

H₂, Pd/C (or Pt, Ni)

Catalytic Hydrogenation Stereochemistry

Syn addition

Catalytic Hydrogenation other

Reduces alkene to alkane

Catalytic Hydrogenation RXN

C=C + H2 → C-C