Table 15 Catalytic reactions using Cu 2 O-coated nanoparticles for Ullmann coupling of imidazole
with various aryl chlorides
a
Entry
Reactant
Product
1
2
3
4
85
90
91
95
Yield (%) b
5
6
7
8
88
86
69
97
9
10
0
0
Cl
O 2 N
Cl
Cl
F 3 C
Cl
OHC
Cl
F
Cl
Cl
N
C l
N
Cl
Cl
Cl
MeO
O
O 2 N
N
N
N
N
O
F 3 C
N
N
OHC
N
N
F
N
N
Cl
N
N
N
N
N
N
N
N
N
N
MeO
N
N
a
5 mol% Cu 2 O-coated nanoparticles and 2 eq. imidazole used, Cs 2 CO 3 , DMSO, 150
C, 18 h
b
Isolated yield
Table 16 Catalytic reactions using Cu 2 O-coated Cu nano particles for Ullmann coupling
of 4-chloroacetophenone with various amines
a
Entry
Reactant
Product
1
2
3
63
86
84
Yield(%)
b
N
H
N
N
H
N
H
N
N
N
O
N
N
O
N
O
a
5 mol% Cu 2 O-coated Cu nanoparticles used, Cs 2 CO 3 , DMSO, 150
C,18 h
b
Isolated yield
Recent Developments in Recyclable Copper Catalyst Systems for C–N Bond. . .
139