Reagents Summarized + Notes

Alkene + Br2, CH₂Cl₂

or

Alkene + Cl₂, CCl₄

Forms Trans Vicinal Dihalide

Halogen Addition to Alkenes - Anti-Addition

One Br/Cl added on each C of Double Bond

Alkene + Br₂, H₂O

Forms Halohydrin

Anti-Addition

Br added on one C, OH added on other C

H3O+ and Br- byproducts

Alkene +

1) Hg(OAc)₂/H₂O

2) NaBH₄/NaOH

THF, H₂O

Oxymercuration-Demercuration

Forms Trans Alcohol

ANTI-ADDITION

OH on more substituted C and H on less substituted C

Alkene +

1) BH₃ / THF

2) H₂O₂, OH^-, H₂O

Forms Alcohol

ANTIMARKOVNIKOV

H on more substituted C

OH on less substituted C

Alkene + O₃, DMS (Me₂S)

Ozonolysis (Reductive Workup)

makes 2 products (each is 1/2 of the alkene)

Forms Ketone if 4R groups

Forms Aldehyde if 2R 2H groups

Forms Formaldehyde if 4H groups

Alkene + O₃, H₂O₂

Ozonolysis (Oxidative Workup)

makes 2 products (each is 1/2 of the alkene)

Forms Ketone if 4R groups

Forms Carboxylic Acid if 2R 2H groups

Forms Formic Acid if 4H groups

similar to reductive workup, except all the H are replaced by OH

Alkene + H₂O, H₂O₂ or

Alkene + H₂O, THF or

Alkene + H₂O, H₃O⁺

Forms Alcohol

Markovnikov unless Borane is present(?)

Alkene +

1) Hg(OAc)₂/CH₃OH

2) NaBH₄

THF, H₂O

Forms Ether

Alkoxymercuration-Demercuration

ANTI-ADDITION

OCH₃ on most substituted carbon, H on least substituted carbon

Alkene +

1) BH₃/(THF or (C₂H₅)₂O or diglyme)

2) H₂O₂, OH^-, H₂O

Forms Alcohol

Hydroboration-Oxidation

ANTIMARKOVNIKOV

SYN-ADDITION

OH on least substituted carbon

H on most substituted carbon

Alkyne + H₂O, (Hg²⁺, H₂SO₄)

Forms Ketone

Adding H₂ on less sub carbon and double-bond O on more sub carbon

Keto-Enol Tautomerization

(Enol is when OH attached to C=C)

Alkyne + BH₃

1) THF

2) H₂O₂, OH^-

Forms Aldehyde or Ketone

Forms Enol which tautomerizes

Aldehyde if alkene has R and H

B adds to less substituted side, H adds to more substituted side

Ketone if alkene has R and R

Terminal Alkyne + Disiamylborane (Bulky)

1) THF

2) H₂O₂, OH^-

Forms Aldehyde

Enol tautomerizes to make aldehyde

Same process as Alkyne + BH3, except BSia replaced by OH instead of just B.

SN₂

Strong Nucleophile

Polar Aprotic

Polar Prot: Methyl-Halide & Primary Halide

Polar Aprot: Methyl-Halide thru Secondary Halide

Strong Base: Methyl-Halide & Primary Halide

Bulky Base: Methyl Halide

Inverses Stereochemistry

Rate: 2 order - K[Nuc][Sub]

SN1

Weak Nucleophile

Polar Protic

Polar Prot: Secondary, Tertiary Halides

Polar Aprot: Tertiary Halides

Rate determined by carbocation

Rate: 1 order - K[Sub]

Methyl/Hydride Shifts can Occur

Carbocation formation is rate limiting step (aka removal of the LG)

E2

Beta-Elimination

Strong/Bulky base

Bulky Base: Primary, Secondary & Tertiary Halides

Strong Base: Secondary & Tertiary Halides

Rate: 2 order - K[Base][Sub]

E1

Beta-Elimination

Weak Base

Polar Aprot for Secondary & Tert Halides

Polar Prot for Tert Halides

Rate: 1 order - K[Sub]

Methyl/Hydride shift can occur

Carbocation formation is rate limiting step (aka. removal of the LG)

Free Radical Rxns

Initiation, Termination, Propagation

Alkyne + Na (liq NH3)

Forms Internal Trans Alkene

(Mechanism: Reduction of Internal Alkyne)

one H added on each C, anti-addition

2Na⁺, NH₂^- byproducts

R-X + Mg, ether

Grignard Reagent (R-MgX)

Organometallic Reagent Formation

X = Halide (Usually Cl, Br, or I)

Int. Alkyne (R-C(trpbond)C-H) + CH3CH2-MgX, THF

Forms Acetylenic Grignard Reagent

(legit just Internal Alkyne but MgBr replaces H)

(H goes to CH3CH2 and makes CH3CH3)

R-MgX + R’-OH

R-H + Mg²⁺+ X^- + R^--O^-

Internal Alkyne + Na⁺, NH₂^-+ NH₃ (liq)

Terminal Alkyne (Sodium Acetylide)

(H on Internal Alkyne goes to NH₂^-)