Tokyo Chemical Industries (TCI) Reagents Guide 8th Edition -Synthestic Organic Chemistry,Materials Chemistry_GH

M
H
(I)
(II)
(III)
(IV)
H
M n
M
X H
M
O
R O H
M
R
H
‡
H
Mn+2
‡
-HX
‡
- RCO 2 H M
‡
-RH
(I) Oxidative addition
Hydrides remain on the metals.
Low-valent metals Ru(0), Rh(I), Pd(0), Ni(0) etc. are used.
Effective to assist intramolecular chelation from the directing group
(II) Electrophilic aromatic substitution (S E Ar)
Hydrogen atom is pulled out as a proton.
Reactive to electron-rich aromatic rings and five-membered heterocycles
Generally, not rate-limiting step and low KIE(kH/kD=1.2~2.0)
(III) Concerted metalation-deprotonation (CMD)
Hydrogen atom is pulled out as a proton.
Reactive to fluorine or nitrogen substituted electron-poor aromatic rings
If C-H bond cleavage is rate-limiting step, showed high KIE(kH/kD=3.5~7.0)
(IV) σ-Bond metathesis
Hydrogen atom is pulled out as a hydrocarbon.
Early transition metal complexes with unsaturated coordination state
Activation of sp 3 C-H bonds
M
DG
H
DG:Directing Group
DG
M
H
DG:
R
O
R= Me, H,
OR, NR2
R
N R'
Z
R
N
Z= O, NR, S
H
N R NMe2
OMe
O
R= Me, NMe 2 CN etc...
F
O
N
H
F
F
CF 3
F
O
N
H
N
N
Si
i-Pr i-Pr
Auxiliary groups aimed at C-H bond activations
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