Chemistry Reference
In-Depth Information
Rh catalyst (3 mol%)
Ag
2
CO
3
(1 equiv)
DME (1 equiv)
m-xylene, MW
200 °C, 0.5h
P[
O
CH(CF
3
)
2
]
3
+
(Het)Ar'
Ar(Het)
(Het)Ar'
H
I
Ar(Het)
Cl
Rh
P[OCH(CF
3
)
2
]
3
CO
Rh catalyst
Ac
OMe
Me
OMe
Me
S
O
S
N
Me
Ac
CN
C-2 57%
C-3 23%
S
94%
52%
66%
Scheme 12.65 Rh-catalyzed direct C-H arylation of (hetero)arenes.
N
N
N
N
PPh
2
THF, rt
Rh
+
[Rh(cod)Cl]
2
N
P
PPh
2
Rh
N
Cl
Cl
N
N
N
insitugenerated
catalyst
X
insitugenerated catalyst (5-10 mol%)
70 °C, 24h
+
R
R
Substrate Scope:
O
2
N
N
NO
2
96% (X=Br, catalyst 5 mol%)
73% (X=Cl, catalyst 10 mol%)
83% (X=Br, catalyst 5 mol%)
70% (X=Cl, catalyst 10 mol%)
83% (X=Br, catalyst 5 mol%)
59% (X=Cl, catalyst 10 mol%)
Scheme 12.66 Bimetallic Rh catalyst for C-H arylation.
Me
Br
R
1
N
[RhCl(CO)
2
]
2
(5 mol%)
dioxane, 190 °C, 24h
+
R
1
N
Me
R
2
Me
Me
R
2
Me
Me
Me
N
Me
N
N
Me
Me
Me
Cl
0%
53%
65%
Scheme 12.67 Direct C-H arylation of pyridines and quinolines.
Pyridine and quinoline moieties were also arylated at the C2 position with
aryl bromides using electron-poor [RhCl(CO)
2
]
2
catalyst. Although pyridines
and quinolines were arylated exclusively at the C2 position with a number of
electron-donating and -withdrawing aryl bromides, unsubstituted pyridine
remained unreacted under the standard conditions (Scheme 12.67).
59
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