Ppt Mekanisme Reaksi Elektrofilik

Mekanisme Reaksi Substitusi Elektrofilik (SE) reaksi substitusi elektrofilik, pada umumnya terjadi pada senyawa aromatik, dan penyerangnya adalah sebuah elektrofil (E +)

Khususnya pada senyawa benzena

Mekanisme reaksinya: Dua tahapan yaitu 1. pembentukan elektrofil dengan bantuan katalis

E + Katalis

Elektrofil Ele ktrofil (E+) +

E   + katalis

. !enyerangan elektrofil pada "in"in benzena

Mekanisme reaksinya: Dua tahapan yaitu 1. pembentukan elektrofil dengan bantuan katalis

E + Katalis

Elektrofil Ele ktrofil (E+) +

E   + katalis

. !enyerangan elektrofil pada "in"in benzena

!eberapa "ontoh pembentukan elektrofil# dengan bantuan katalis Elektrofil (E+) Elektrofil  (E+)

#$l + %l$l&

#+ + %l$l'

r  + *er &

r + + *er '

,-& + -' -' (berasap)

,-+ + -&+ + -'

,-& + -'

,-+ + -

1. eberapa reaksi E pada "in"in benzena alkilasi

Sulfonasi

asilasi

$ontoh: asilasi Friedel-Crafts

Mekanisme reaksinya.................

Mekanisme reaksinya.................

agaimana membuat senyawa tersebut dari benzena..../

asilasi Friedel-Crafts dalam industri pembuatan bensaldehid 

$ontoh: alkilasi Friedel-Crafts

,oti"e the stabilization of formed "arbo"ation as ele"trophile

enzene alkylation with akene

enzene alkylation with an al"ohol

-btain the mayor produ"t and its rea"tion me"hanism when an alkylhalide is rea"ted with benzene by Friedel-

Crafts alkylation

1. "hloroetane ."hloropropane &. "hlorobutane '. 1"hloro0dimetihylpropane . 1"hloromethylpropane

. *ungsionalization og subtituted benzene tersubstitusi (e"ond substituen)

5 is first subtituen and dire"t the se"ond subtituen (E+) and effe"t rea"tion rate

-rto 3!ara

%tau Meta

4f 5 is ele"tron or releasing a"ti6ated benzene ring

4f 5 is ele"tron withdrawing or dea"ti6ated benzene ring

7hree fa"tors effe"t aromati" E rea"ti6ity: (1) Kineti"s () Ele"tron density (&) tability of formed "omple8 (related to the present of resonan"e)

Kinetis0 e"ond substituen orientation "an be determined by subtituent "onstanta formula k = equilibrium constante with substituent  k o = equilibrium constante without substituent  β = RX factor  σ = substituent constante

Ele"tron density0 ubstra"t ele"tron density is effe"ted by first subtituen. 4t "an be noti"ed from their effe"t: mesomery indu"ti6e effe"t

(M) and

($).

E8amples: ubtituen 9,

(M)  + dan (4)  %

o0p dire"ting

ubtituen 9$&

(M)  + dan (4)  +

o0p dire"ting (Ekstrim)

ubtituen 9$l dan 9- ubtituen 9,-

(M)  + dan (4)  % (M)  % dan (4)  %

o0p dire"ting m dire"ting (Ekstrim)

$omple8 stability #esonan"e stru"ture showed stability grade. e"ond subtituen orientation on aromati"s (benzene): ;0p or m0 is depend on stabilisation resonan"e

E&les# than bromine0 so it "ontrols the regiosele"ti6ity of nitration.

7here are se6eral fa"tors effe"t the third substitue to 1.

-bser6e and gi6e your "on"lution: ............................................... ..............................................

.

?hat is your "on"lution:

............................................... ..............................................

&.

?hat is your "on"lution

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