Mechanisms Flashcards
Halogenation
What is being added?
Br2 or Cl2
What intermediate is within a bromination mechanism?
bromonium ion
What is the expected stereochemistry of halogenation?
Anti addition
Hydroboration Oxidation
What is being added?
H and OH
What are the reagents used in Hydroboration?
- BH3, THF/ 2. H2O2 or NaOH
What are the reagents used in Halogenation?
Bromine/Chlorine and CCl4
What is the regioselectivity in Hydroboration?
H to less H, OH to less substituted.
Anti- Markovinov
What is the expected stereochemistry in hydroboration?
Syn Addition
What reagents are used in Halohydrin
Bromine/Chlorine and H2O
Halohydrin
What are we adding across DB?
Br/Cl and OH
Regioselctivity of Halohydrin
OH adds to more substituted
Sterochemistry of Halohydrin
Anti Addition
Water adds anti to halide
Acid-Catalyzed Hydration
What is being added?
H and OH
Regioselectivity of Acid-Catalyzed hydration
Markovinov
OH to more substituted, H to more H
Hydrogenation
What is being added?
H2
What is the stereochemistry of hydrogenation?
Syn Addition
Epoxidation
What is being added?
An O, from a peroxy acid
What reagent is used in Epoxidation?
MCPBA or peroxyacetic acid
What is the stereochemistry of epoxidation?
Syn addition
O binds to both carbons on same plane
What reagents do you use for substitution with triple bonds?
NaNH2, NH3, ether, or THF
What hints at an SN2 mechanism?
A full negative charge on the nucleophile
When can we do an alkylation using triple bonds?
Only when theres a leaving group on a primary or methyl carbon
Which radical structure is most stable
3 prime
What is the major product of a reaction with H-halogen and HOOH?
Radical on most substituted, halogen on least substituted
