Intermediates occur
at relative minima in the reaction graph
to break a bond
requires energy (endergonic)
forming bonds
releases energy (exergonic)
intermediates form as a result of
breaking bonds
homolytic cleavage
breaks a bond forming 2 free radicals
heterolytic cleavage
When the bond breaks, the most electronegative atom gets both electrons
carbenes
both nucleophilic and electrophilic
Bond dissocation energy
energy needed to break a covalent bond
carbocations hybridization
sp2
free radical hybridization
sp2
carbanion hybridization
sp3
carbene hybridization
sp2
factors that stabilize free radicals
resonance
hyperconjugation
BDE and radical stability
inverse
to start a free radical reacion
use light
mechanism steps
1 braking bond
2 forming a new bond
3 both at same time
energy and ----- are closely related
structure
fluorination reactions are
hard to control
in chlorination reactions
secondary hydrogen are favored at 60 percent
Bromination reactions
attach to the location of the more stable radical
things that affect reaction efficiency
less steps better
less side reacitons
less byproducts
no equilibrium reactions or non favored reaction
most stable radicals
tertiary benzylic and allylic
E1 Reactions with Alcohols
Require strong acid catalysis
to get an alcohol from an alkene use?
water
Regioselectivity
preferential formation of one constitutional isomer over another
heat of hydration
and stability are inverse
stability of alkenes
trans>geminal>cis