Chemistry Reference
In-Depth Information
5-10 mol % CuI
10-20 mol %
29
K
3
PO
4
,DMSO,80-110°C
Ar
1
OH
ArOAr
1
ArX
+
Ar
1
Ar
X
Yield (%)
Pyrimidin-5-yl
Br
C
6
H
5
70
Isoquinolin-4-yl
Br
3,4-(CH
3
)
2
C
6
H
3
69
o
-CH
3
C
6
H
4
I
2,6-(CH
3
)
2
C
6
H
3
89
o
-(
i
C
4
H
9
)C
6
H
4
I
2,6-(CH
3
)
2
C
6
H
3
74
o
-CH
3
OC
6
H
4
I
C
6
H
5
85
o
-ClC
6
H
4
I
o
-CH
3
C
6
H
4
68
Scheme 6.9
5mol%CuI
5mol%
34
Cs
2
CO
3
,DMF,rt-80°C
R
1
R
1
+ ArOH
X
OAr
R
R
R
1
R
X
Ar
Yield (
)
Ph
H
Br
o
-
i
PrC
6
H
4
90
Ph
H
I
o
-
i
PrC
6
H
4
95
H
H
I
3,5-(OCH
3
)
2
C
6
H
3
84
H
H
I
p
-FC
6
H
4
81
H
CO
2
Et
I
p
-
t
BuC
6
H
4
93
H
CO
2
Et
I
Benzothiazol-2-yl
92
Scheme 6.10
the vinyl ether product under the coupling conditions. Hence the proper
choice of ligand in this chemistry may not only affect the product con-
version, but can also affect the final geometry of the product. For example,
certain copper catalysts have shown an increase in stereoselectivity of the
vinyl ether with respect to the starting vinyl halide, whereas some catalysts
simply retain the E:Z ratio of the vinyl halide starting material during the
transformation to the product.
6.3.3 Copper-Catalyzed Coupling Reactions of Aryl Halides
With Aliphatic Alcohols
Copper catalysts have also been shown to promote cross-coupling reactions
of aryl bromides and iodides with primary and secondary alcohols
(Scheme 6.11).
51,52,56
Reactions with primary alcohols are typically higher
yielding and require lower catalyst loadings than related reactions of
secondary alcohols. However, the requirement for neat alcohol to provide
a higher yield of product is a drawback to the current methodology, as
the reaction of uncommon, expensive primary alcohols would not be cost-
effective.
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