tóm tắt phản ứng hóa hữu cơ part 1 hóa học hữu cơ là một ngành khoa học nghiên cứu về những cấu trúc, tính chất, thành phần, cách thức phản ứng, và cách tổng hợp của những hợp chất hữu cơ và vật liệu hữu cơ... cũng như nhiều vật chất khác nhau chứa nguyên tử carbon.12 Quá trình nghiên cứu cấu trúc hóa học của một hợp chất hữu cơ có thể ứng dụng nhiều thành tựu trong các lĩnh vực khác phải kể đến như phương pháp quang phổ, phương pháp vật lý và hóa học để định danh và xác định thành phần hóa học cũng như cấu tạo của hợp chất.3 Hóa hữu cơ nghiên cứu các đặc tính lý hóa của hợp chất, đánh giá mức độ phản ứng cũng như xác định tính chất của chúng ở trạng thái tinh khiết, trong dung dịch, hỗn hợp và các dạng khác. Các nghiên cứu về phản ứng hữu cơ có thể kể đến bao gồm việc chuẩn bị cho các phản ứng tổng hợp hữu cơ, nghiên cứu mức độ hoạt động của phản ứng, cũng như nghiên cứu các mô hình lý thuyết trên máy tính
Trang 1H H
HBr
H
CH3
Br H
H H
Addition of HX
(Mark)
*Adds a halide
to more substituted carbon
HBr ROOR
H
CH3
H Br
H H
Addition of HX
(Anti-Mark)
*Adds a halide
to least substituted carbon
Br2
CH2Cl2 (or CCl4)
Add two Br's anti
to alkene
*Anti and co planar
CH 3
D
CH 3
Br
Br D
Adding a Br and
OH (Mark w/ Br as H
and anti-planar)
CH 3
D
CH 3
Br
OH D
Br2
H2O
Forming alkene
from vicinal dihalide
*Anti and co planar
Br
C
H3
H H
NaI or KI acetone
H
CH3
H
C
H3
*Wedges with wedges and dashes with dashes
*E2 Like!
Dehydration to
*E1 like and it cannot give terminal alkene
H2SO4 heat
OH
POCl3 heat
*SPECIAL REACTION: dehydrates to form terminal alkene
Addition of OH
CH3
CH3
CH3
OH
*CANNOT CONTROL STEREOCHEM!
*Low yield!
*C+ formation!
H3O+
Trang 2demercuration
(Add OH from alkene
mark and antiplanar)
*Complex mechanism
*Mark and antiplanar
CH 3
D
CH 3
H
OH D
1) Hg(OAc)2/ H2O 2) NaBH4
Hydroboration
(Add Oh anti-mark and
syn planar)
*Anti-mark
*Notice Peroxide
CH3
D
CH3
D OH
H
1) BH3 / THF 2) H2O2 / -OH
SPECIAL: Adds alcohol
instead to form ethers!
CH 3
D
CH 3
H
O D
CH 3
1) Hg(OAc)2/ CH3OH 2) NaBH4
*Complex mechanism
*Mark and antiplanar
*WILL BE SEEING THIS MORE IN ORGO II
CH3 C
H3
D
CH3
CH3 C
H3
D C
H3 H H
H2
Pt, Pd, or Ni
Catalytic Hydrogenation
(Alkenes -> Alkane, Syn
Addition of H)
*Steric factors must be payed attention to
*Can use D2 instead
Formation of
Vicinal Diols
(Syn)
CH 3
D
CH 3
D
OH OH
CH 3
D
OH OH
CH 3
D
OsO4
H2O2
KMnO4 cold, basic
*expensive
*toxic
*great yield
*cheaper
*safer
*poor yield
Trang 3(double bond cleavage)
*Can use Zn/acetic acid instead of (CH3)2S
*Can isolate the formaldehyde
1) O3 / CH2Cl2 2) (CH3)2S
R
R
O
R R O
R
1) O3 / CH2Cl2 2) (CH3)2S
H
R
O
H R O
R
1) O3 / CH2Cl2 2) (CH3)2S
H
R
O
H H O
R
warm
R
R
O
R R O
R
H
R
O
OH R
O
R
H
R
O
R
KMnO4 warm
KMnO4 warm
CO2 + H2O
*further oxidizes to form carboxylic acids
*cannot isolate the formaldehyde
Carbene / Carbenoid
addition (formation of
cyclopropane)
CH 3
D
CH2N2 heat
CH 3
D
D
C
H3
CH2I2
C
H3
*syn
*stereochem is preserved
*Second reaction uses the Simmons-Smith reagent
Formation of epoxides
from alkenes
*useful for synthesis (ESPECIALLY IN ORGO II)
CH 3
D
CH 3
D O
MCPBA
Trang 4Opening of Epoxides
NOTE: Can use RO
-to form ethers You
will see this in Orgo II
*acidic conditions opens from more substituted side
*Basic are like SN2 (least substituted side)
*Please look up mechanism
H3O+
H2O
CH 3
D O
CH 3
D OH OH
CH 3
D O
1)-OH 2)H3O+
OH
OH D
CH 3
Formation of
Dibromocarbenes and
Dichlorocarbenes
CH 3
D
D
C
H3
CHCl3 KOH
CH 3
D
Br Br
CHBr3 KOH
D
3
C
H3
Cl Cl
Formation of the
-*forms the nucleophile that is handy when connecting carbons!
Uses of the acetylide
anion
with methyl or 1 o halides
C
*SN2 because of the exception we learned from before!!!!
with 2 o or 3 o halides
C
test!!!
C
with carbonyl groups (ketones, aldehydes, and formaldehydes)
C
H3 C CH3
O
C
-1) 2) then H3O+
C
H3 C C
C
O H
*acetylide anion attacks partially positive carbon
*DO NOT FORGET then H3O+
*please look up the mechanism so you can see how the carbene
is formed
Trang 5Synthesis of Alkynes *Need either geminal or
vicinal dihalides
*Look up mechanism
*NaNH2 gives terminal
*KOH gives internal
1) NaNH2 / 100oC 2) H3O+
C
H3 CHCH CH3
Br Br
CH2CHCH2CH3
Br Br
C
H3 C CH2CH3 Br
Br
C
H CH2CH2 Br
Br
C
Halogenation of alkynes Br2 and alkyne
C
(1 eq)
Br
C
Br
Br
C
H3
+
*Stereochem cannot
be controlled
HBr and alkyne
C
HBr (1 eq)
HBr (2 eq)
H
C
H3
Br Br
*Mark
*syn addition
HBr and alkyne
C
HBr ROOR
H
C
H3
*Anti mark
*syn addition
Catalytic reduction with
reactive catalyst
C
Pt, Pd, or Ni
*Takes it all the way back
to alkane
*generally bad yield
Trang 6Alkyne to Alkene:
TRIPLE to DOUBLE
*isolates an alkene with
a SYN addition of H
H2 / Pd(BaSO4) quinoline
C
CH3
C
H3
Lindlar's catalyst
Dissolving metal
C
H
C
H3
*isolates an alkene with
an ANTI addition of H
Addition of H-OH to
alkynes
Mercuric Ion
C
H3
HgSO4 / H2O
H2SO4
HgSO4 / H2O
H2SO4
C O
CH3
CH2 C
H3
C
H3
C O
CH2
CH2 C
C O
CH3
CH2
CH2 C
H3
+
*Mark addition
*If not terminal, you will get a mixture
*Formation of ketone
Hydroboration
C
H3
1) Sia2BH 2) H2O2 / -OH
C O
H
CH2
CH2 C
H3
*Antimark addition
*will get a mixture if not terminal
*Formation of aldehyde
Oxidation of alkynes
KMnO4 / H2O neutral / cold
O
O
C
KMnO4 / H2O neutral / cold
O
OH O
*Forms vicinal carbonyls
*further oxidizes terminal alkynes to form
carboxylic acid
Trang 7Cleavage of Alkynes: *Forms H2O and CO2
if terminal
C
Oxidation of alkyne (strong)
1) KMnO4 / H2O 2) -OH / heat
O
OH C
H3
C
2) -OH / heat
O
OH
O
CDH2
+
O
O
Ozonolysis
1) O3 2) H2O
C
O
OH C
H3
+ O
O
C
OH
O
1) O3 2) H2O
*Same products as previous
The Grignard Reagent
C
H3
Br
H Mg
H
MgBr
*Forms from 1o, 2o, 3o, allyl, vinyl, and aryl carbons
The Organolithium
Li
*This reagent acts like grignard but is stronger
Formation of alcohols
from Grignard
1 o alcohols (Grignard and formaldehyde)
MgBr
O H H
1)
*Know this mechanism!
*Carbon attachment
2 o alcohols (Grignard and aldehyde)
MgBr
O H
1)
*Know this mechanism!
*Carbon attachment
3 o alcohols (Grignard and ketone)
MgBr
O
OH
*Know this mechanism!
*Carbon attachment 1)
2) H3O+
Trang 8Grignard and esters
or acid halides
*Reaction goes until completion
*Know this mechanism!
MgBr
O
OCH3 1)
2) H3O+
OH
Grignard and Epoxides
2) H3O+
OH
MgBr
*SN2 like (attacks least substituted side)
*Know this mechanism!
Attaching Deuterium to
*This is just good to know
Corey-House Reaction
+
Br
*not well understood (do not need to know mechanism)
*another way to attach carbons
Hydride reduction of
carbonyls
mild conditions (NaBH4 as reagent)
EtOH
OH
O
Cl
NaBH4 EtOH
no reaction
*reduces only
aldehydes and ketones.
*use alcohols as a solvent
strong conditions (LiAlH4 as reagent)
O
OH
1) LiAlH4 / ether
O
O
1) LiAlH4 / ether
+ OH
*reduces aldehydes, ketones, esters, acid halides, carboxyllic acids.
*Use ethers solvents
*Two step process
Trang 9Raney Nickel *Reduces both carbonyl
and alkene
H2 Ra-Ni
Oxidation of alcohols 2 o alcohols
OH
Na2CrO7
H2SO4 / H2O
CrO3 / H2SO4 / H2O acetone / 0 o C (Jones reagent)
PCC
CH2Cl2
O
*any [ox] can be used
*KMnO 4 and NO 3 can
be used but they are harsh
1 o alcohols
OH
Na2CrO7
H2SO4 / H2O
CrO3 / H2SO4 / H2O acetone / 0 o C (Jones reagent)
PCC
CH2Cl2
O OH
O H
*PCC is the only one that can isolate the formaldehyde
Formation of the
Tosylate Ester
*RETENTION from
where alcohol was
originally (SN2 purposes)
Formation of alkyl halide
from 3o alcohols
Trang 10Formation of 1o/2o
alkyl halides from 1o/2o
alcohols
*Basically an SN2 reaction (Inversion from original alcohol)
*Can also use SOCl2 for Cl, but it undergoes
a special mechanism!
PBr3
CH2Cl2
C
Br CH3
Cl CH3
I CH3
PCl3
CH2Cl2
P / I2
CH2Cl2
Unique cleavage with
HIO4
OH
CH3 OH H
HIO4
O
CH3 H
O
*Vicinal diols must
be syn
Williamson ether
O
-O
*Basically that SN2 exception we learned
in test 2
Pinacol - Pinacolone
Rearrangement
OH OH
H2SO4
*Know mechanism (methyl shift!)
+
C O
O
H+
C O
CH2 C
H3
*CAN USE ACID HALIDE instead of
carboxyllic acid!!!
Formation of Alkoxide
1 o or 2 o alcohols
2 o or 3 o alcohols
OH
O
-O
-Nao
Ko
Ethers from intermolecular
dehydration
2x CH3CH2-OH H2SO4 CH3CH2-O-CH2CH3
140oC
*Must be identical alcohols or else you
will get a mixture!!!