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H
O
HO
2
CO
Pd
C
O
Pd
HO
Br
-
PR
3
PR
3
assisted intramolecular
HCO
3
-
H
2
CO
3
H
Br
Pd
Br
Pd
Pd
PR
3
PR
3
PR
3
not assited
Br
-
HCO
3
-
HO
2
CO
H
HOO
2
C
Pd
Br
Pd
PR
3
H
2
CO
3
PR
3
assisted intermolecular
Figure 12.2 Proposed mechanism for the intramolecular ortho-arylation of phenols.
H
Pd(OAc)
2
(0.1-2.0 mol%)
ligand
A-E
K
2
CO
3
,DMA,125-145°C
Z
R
2
R
1
X
Y
R
1
R
2
X
Y
Z= Cl, Br
X-Y = O-CH
2
,Ts-N-CH
2
,RN-CH
2
,RN-CO,HC=CH,CH
2
-CH
2
,NH
CF
3
i
Pr
i
Pr
P
Cl
PPh
2
N
N
Ph
Me
2
N
i
Pr
i
Pr
A
B
C
CF
3
N
N
Ar
Ar
Me
Me
Me
Me
P
AcO
PdOAc
Me
Me
E
HBF
4
P
Me
D
C1
H
2
O
HBF
4
Ar = 2,6-
i
Pr-C
6
H
5
Scheme 12.6
Screening of various ligands for Pd-catalyzed intramolecular direct
arylation.
support substrate was treated with Pd(OH)
2
/C, followed by cleavage with
TFA. Full conversion was observed, which indicated that a soluble catalyst
species had leached into solution. The homogeneous nature of the active
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