Table 26 Coupling of aryl chlorides with amines catalyzed by Cu/Al-HTB
a
DMF
100 °C
6-32 h
Cl
NHR 2 R 3
Cu/Al-HTB catalyst
K 2 CO 3
R
1
+ HNR
2 R
3
R
1
Entry
R
1
R
2
R
3
Time (h)
Yield (%)
1
2-Me
H
n-C 8 H 17
32
42
2
4-COOH
H
n-C 8 H 17
8
9 7
3
4-Cl-2-CHO
H
n-C 8 H 17
8
9 5
4
H
H
Cyclopentyl
16
n.r.
b
5
2-Me
H
Cyclopentyl
20
n.r.
b
6
4-COOH
H
Cyclohexyl
14
73
7
4-Me
–(CH 2 ) 5
À
28
52
8
4-I
–(CH 2 ) 5
À
9
8 1
a
Aryl chloride (1.0 mmol), amine (1.2 mmol), catalyst (2.5 mol%), K 2 CO 3 (1.2 mmol), DMF
(2.0 mL) stirred at 100
C
b
n.r ¼ no reaction
Table 25 Cu/AI LDHs-catalyzed C–N bond forming reactions between octylamine and 2-nitro
chlorobenzene
a
Octylamine
100 °C
6-8 h
Cl
NH
Cu/Al HT catalyst
K 2 CO 3 (1.2 eq.)
NO 2
NO 2
Entry
Catalyst
b
Yield (%)
1
Cu(HAP)
n.r.
c
2
Cu(FAP)
n.r.
c
3
Cu(II)-NaY
32
4
SiO 2 -Cu(OAc) 2
36
5
Cu/Al-HTA
65
6
Cu/Al-HTB
96,97
d
7
Cu/Al-HTC
90
a
1-Chloro-2-nitrobenzene (1.0 mmol), amine (1.2 mmol), catalyst (2.5 mol%), K 2 CO 3 (1.2 mmol)
DMF (2.0 mL) stirred at 100
C
b
Cu-(HAP), copper hydroxyapatite; Cu-(FAP) copper flouroapatite, Cu/Al-HTs (HT, Hydrotalcite
of Cu/Al in different ratios) Cu/Al-HTA, 3:1(Cu: Al); Cu/Al-HTB, 2.5:1; and Cu/Al-HTC, 2:1)
c
n.r ¼ no reaction
d
Isolated yield after fifth cycle
Recent Developments in Recyclable Copper Catalyst Systems for C–N Bond. . .
151