Chemistry Reference
In-Depth Information
Table 4.8
Suzuki coupling with aryltriazenes.
x
(2 mol%)
Ar
N
N
N
+
r'
(OH)
2
A r
Ar'
BF
3
.Et
2
O
dioxane, RT
N
N
Na
2
CO
3
DMF/H
2
O(1:1)
O
supported Pd-NHC
32
+P (OA
2
N
N
2X
X = Cl or I
Ar
0
Entry
Ar
Product
Yield (%)
O
2
N
1
3-NO
2
C
6
H
4
Ph
92
2
4-IC
6
H
4
Ph
66
I
3
4-BrC
6
H
4
Ph
71
Br
4
4-MeC
6
H
4
4-MeOC
6
H
4
82
OMe
NO
2
5
Ph
3-NO
2
C
6
H
4
74
[Pd(IPr)(Im)Cl
2
]
(
16a
)
(1 m o l % )
X
B(OH)
2
R
+
R
R''
K
3
PO
4
.H
2
O
morpholine, 11 0°C
R''
X=OTsorOMs
OMe
F
OMe
N
X=OTs:94%
X=OMs:62%
X=OMs:52%
X=OTs:81%
F
OMe
X=OTs:93%
X=OTs:40%
Scheme 4.12
Suzuki reaction using aryl sulfonates.
4.3.1.2.1 Origins and Advances in Coupling Using Pd-NHC Systems.
The first publication on the use of a Pd-NHC system in the Negishi re-
action appeared in 2005.
74
This involved an in situ-generated catalyst com-
posed of Pd
2
(dba)
3
and IPr
HCl (2 and 8 mol%, respectively). The system
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