1. Gc t do, carbocation, carbanion, carben, arin1.1. Gc t do: l cht trung gian c t nht mt in t c thn trn mt nguyn t.1.2. Carbocation: Nhng nhm th y in t gn vo cacbon mang tch (+), lm n nh carbocation. bn gim dn t carbocation bc 3 n carbocation bc 1.1.3. Carbanion: l cht trung gian c mt tch (-) trn mt cacbon. Xung quanh cacbon mang tch (-) c 8 t.1.4. Carben: l nhng cht trung ha ca cacbon ha tr 2, xquanh C c 6 t gm 4 t lin kt v 2 t t do.1.5. Arin: l cht trung gian c hot tnh mnh, c th xem nh dn xut aren bng cch tch 2H. C CH PHN NGChng 3: (3Tit)

VD.

C CH PHN NGChng 3: (3Tit)

2. C ch phn ng2.1. C ch phn ng th i nhn (SN)* KN: L loi phn ng m trong nguyn t hoc nhm nguyn t ca cht ban u c thay th bi nguyn t hoc nhm nguyn t khc. Ch yu xy ra nguyn t cacbon no.* VD:

Phn loi: Gm 2 loi: - P th i nhn lng phn t (SN2) - P th i nhn n phn t (SN1) C CH PHN NGChng 3: (3Tit)

* C ch: Khi cho 1 tc nhn ion (-) hoc cc hp cht t do tc dng vi RX iu kin nht nh:

* Trong : - Tc nhn Y- (mang tch m) thng l cc nhm: OH-, RO-, RCOO-, I-, Br-, Cl-, F-- R: gc hidrocacbon- X: Nhm b th C CH PHN NGChng 3: (3Tit)

2.1.1. C ch th i nhn lng phn t (SN2)- L phn ng xy ra theo c ch 1 giai on c qua trng thi chuyn tip.- Cc phn ng thy phn ca dn xut halogen no bc 1 thng xy ra theo c ch SN2 C CH PHN NGChng 3: (3Tit)

2.1.2. C ch th i nhn n phn t (SN1)- L phn ng xy ra theo c ch 2 giai on ion ha v kt hp cation: * Giai on 1: ion ha, chm

* Giai on 2: kt hp cation, nhanh

- Cc phn ng thy phn ca dn xut halogen no bc 3 thng xy ra theo c ch SN1 C CH PHN NGChng 3: (3Tit)

C CH PHN NGChng 3: (3Tit)

2.1.3. Cc yu t nh hng n phn ng th i nhn- Cation to thnh cng bn, SN1 cng mnh:

- Tnh i nhn ng bin vi tnh baz, ngoi tr dy halogen.- Tnh i nhn trong dy halogen: I- > Br- > Cl- > F-- Tnh i nhn cng cao cng u tin xy ra c ch SN2: C CH PHN NGChng 3: (3Tit)

2.1.4. Cnh tranh gia SN1 v SN2- Cc tc cht c tnh nucleophil ngho nh: H20, CH3OH : SN1- Cc tc cht c tnh nucleophil giu: HO-, CH3O- : SN2- Metyl v halogenur alkyl bc 1 : SN2- Halogenur alkyl bc 2 : SN1 v SN2- Halogenur alkyl bc 3 : SN1 C CH PHN NGChng 3: (3Tit)

Tm li:- Khi halogenur alkyl c th xy ra phn ng SN1 v SN2, phn ng SN2 s u tin khi nucleophil giu in m trong dung mi phn cc phi proton nh: (CH3)2SO (DMSO), CH3CN (MeCN), (CH3)2NCHO (DMF), (CH3)2CO (Me2CO), CH3Cl2.- Ngc li, phn ng SN1 u tin khi nucleophil ngho trong dung mi phn cc proton nh: H2O, HCOOH, CH3OH, C2H5OH, CH3COOH (AcOH), (CH3)3OH C CH PHN NGChng 3: (3Tit)

2.2. C ch phn ng cng (A)KN: Phn ng cng xy ra khi c s kt hp gia phn t ca cht ban u vi tc nhn phn ng.VD C CH PHN NGChng 3: (3Tit)

2.2.1. Cng hp i in t AE- Cc hp cht alken, alkyl, alkadien d cho phn ng cng hp vi halogen (X2), HX, H2O, H2SO4, HOX* Quy lut cng hp AE:- Tun theo quy tc Maskovnhikov (hydrocacbon bt i xng): Tc nhn i in t X+ s cng hp vo C c ni i cha nhiu H, y- s cng vo C c t H VD: C CH PHN NGChng 3: (3Tit)

- Quy tc Saytseff-Waifner (hydrocacbon cha C ni i cng bc): Tc nhn i in t X s cng hp vo C c ni i lin kt vi C c nhiu H hn C CH PHN NGChng 3: (3Tit)

* nh hng ca cc nhm th:- Mt e- ca lin kt cng nhiu =>Kh nng cng hp AE cng gim.- Kh nng phn ng ca cc olefin: C CH PHN NGChng 3: (3Tit)

2.2.2. Cng hp i nhn AN- L phn ng c trng ca hydrocacbon, l phn ng cng hp ca i nhn vo lin kt i.- C s chnh lch ln gia 2 nguyn t mang ni i.- C s y e- ni i to nn s phn cc: C = O.- Khi cng hp, tc nhn i nhn (-) vo u mang in tch (+), tc nhn i in t cng vo u (-). C CH PHN NGChng 3: (3Tit)

* nh hng ca cc nhm th:- Cc nhm th mang hiu ng y e- (+I, +R, +H) =>Gim e- ca C => Kh nng cng hp AN gim.- Kh nng phn ng ca cc hp cht cacbonyl: C CH PHN NGChng 3: (3Tit)

2.3. C ch phn ng tch loi (E)KN: L loi phn ng m tch 1 phn t ra khi hp cht ban u m khng c s thay th bng nhng nguyn t khc, sn phm to thnh l nhng hydrocacbon khng no (alken, alkyn..)* Tng qut: C CH PHN NGChng 3: (3Tit)

VD

C CH PHN NGChng 3: (3Tit)

2.3.1. Phn ng tch lng phn t E2

Vi: - X: Cl, Br, I, ... - Y: OH-, RO-, NR3, C6H5O- (Y- : mt anion hay phnt trung ha vi cp e cha s dng (baz) - V = K[RX][Y-] C CH PHN NGChng 3: (3Tit)

VD.

- C ch 1 giai on v trng thi chuyn tip- Dn xut hydrocacbon bc 1 thng xy ra - Tc phn ng tch E2 gim theo th t: I> Br> Cl>F- Phn ng kh E2: u tin vi nucleophil nng cao ca baz mnh v trong dung mi phn cc khng proton nh DMSO, DMF C CH PHN NGChng 3: (3Tit)

2.3.2. Phn ng tch n phn t E1

- Phn ng kh E1 thng xy ra vi cc dn xut HC bc 3 C CH PHN NGChng 3: (3Tit)

2.3.3. Cnh tranh gia E1 v E2 C CH PHN NGChng 3: (3Tit)

* Quy tc tchQuy tc Zaixep: nhm th X b tch ra cng vi nguyn t H C c bc cao nht v to ra ni i c nhiu nhm th nht.

C CH PHN NGChng 3: (3Tit)

- Quy tc Zaixep p dng cho c E1 v E2, nhng i vi E2 c trng hp ngoi l sau: Trng hp X l nhm th mang in dng nh : +NR3, +SR2 => Phn ng tch E2 s xy ra theo quy tc Hopman: X b tch cng vi nguyn t H C c bc thp hn ngc vi quy tc Zaixep C CH PHN NGChng 3: (3Tit)

BTVNBi tp mu.-Bi tp t gii chng 3 trong gio trnh Ha hu c: bi 1-20/trang 147-150. C CH PHN NGChng 3: (3Tit)