Entry
|
Catalyst (mol %)
|
Reaction conditions
|
Yield of 4a (%)b
|
Yield of 6a
(%)b
|
1 |
- |
130 °C, 1 h, air |
82 |
0 |
2 |
- |
DMSO, 130 °C, 1 h, air |
64 |
0 |
3 |
- |
CH3CN, 130 °C, 1 h, air |
78 |
0 |
4 |
- |
THF, 130 °C, 1 h, air |
66 |
0 |
5c
|
- |
130 °C, 1 h, air |
51 |
0 |
6d
|
- |
130 °C, 1 h, air |
67 |
0 |
7e
|
- |
130 °C, 1 h, air |
76 |
0 |
8 |
- |
120 °C, 1 h, air |
70 |
0 |
9 |
- |
140 °C, 1 h, air |
74 |
0 |
10 |
- |
130 °C, 16 h, air |
58 |
8 |
11 |
CuCl (20) |
130 °C, 16 h, air |
Trace |
66 |
12 |
CuBr (20) |
130 °C, 16 h, air |
Trace |
39 |
13 |
CuI (20) |
130 °C, 16 h, air |
Trace |
56 |
14 |
CuCl2 (20) |
130 °C, 16 h, air |
Trace |
53 |
15 |
CuO (20) |
130 °C, 16 h, air |
Trace |
55 |
16 |
CuCl (5) |
130 °C, 16 h, air |
Trace |
40 |
17 |
CuCl (20) |
130 °C, 16 h, O2
|
Trace |
45 |
18 |
CuCl (20) |
130 °C, 16 h, N2
|
71 |
Trace |