Organic reactions Flashcards
(17 cards)
The 3 types of organic reaction
Addition (A)
Pi bond broken.
Elimination (E)
Pi bond formed.
Substitution (S)
Substituent replaced.
Electrophile
Seeks electron pair.
Nucleophile
Supplies electron pair.
Curley arrow notation
Indicates the movement of an electron pair.
A_E
Electrophilic addition.
An electrophile attacks a double or triple bond in a molecule, breaking the pi bond and forming two new sigma bonds.
Halogenation
e.g. F-F (addition of a halogen).
Bromination
Br-Br and H-OH (addition of bromine).
S_EAr
Electrophilic aromatic substitution mechanism.
An atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile.
Hydrobromination
H-Br (addition of hydrogen bromide).
Hydrochlorination
H-Cl (addition of hydrogen chloride).
Hydration
H-OH (addition of hydroxyl group).
Markovnikov’s Rule
When a hydrogen is bonding to an anti-symmetric reagent, it will prefer to bond to the carbon with more hydrogens.
This creates major and minor products.
Carbocation
A central carbon. The more carbons it is bonded to the higher its stability.
Primary < Secondary < Tertiary
A_E catalyst
Accelerates the addition of an electrophile to an alkene or alkyne by generating a reactive intermediate.
Lindlar’s catalyst
Palladium deposited on a calcium carbonate plate then poisoned with lead. Used in the hydrogenation of alkynes (triple) to alkenes (double).
Syn-
The reaction occurs on the same side.
Anti-
The reaction occurs on the opposite side.
