Reaction mechanisms. Ionic Reactions. Ionic Reactions. Ionic Reactions. Ionic Reactions. Bond Polarity. Partial charges. Nucleophiles and Electrophiles. Leaving Groups. Radical Reactions. Type of Reactions. Nucleophilic reactions: nucleophilic substitution (S N ).
Nucleophilic substitution: -> reagent is nucleophil
-> nucleophil replaces leaving group
-> competing reaction (elimination + rearrangements)
-Elimination: removal of atoms or groups of atoms from adjacent carbons to form a carbon-carbon double bond
-> acting as a strong base
Elimination, strong base, high temp.
SN2, weak base, good nucleophil
SN1 (+Elimination), strong base, good nucleophil, protic solvent
I is a weak base (SN2)
I better leaving group than Cl
Also 1,3- and other shifts are possible
The driving force of rearrangements is -> to form a more stable carbocation !!!
Happens often with secondary carbocations -> more stable tertiary carbocation
Rearrangement of a secondary carbocations -> more stable tertiary carbocation
Plays an important role in biosynthesis of molecules, i.e. Cholesterol -> (Biochemistry)