Table 2.
Optimization of the amounts of VI, VII, and DMBQ.
|
Entry[a] |
VII [mol %] |
VI [mol %] |
DMBQ [mol %] |
GC yield 10 min [%][b] |
GC yield 60 min [%][b] |
|---|---|---|---|---|---|
|
1 |
10 |
40 |
120 |
81 |
81 |
|
2 |
10 |
2 |
20 |
50 |
54 |
|
3 |
10 |
2 |
40 |
67 |
74 |
|
4 |
20 |
2 |
20 |
65 |
76 |
|
5 |
20 |
4 |
40 |
70 |
80 |
|
6 |
10 |
4 |
40 |
68 |
75 |
|
7[c] |
10 |
4 |
40 |
18 |
41 |
|
8[d] |
10 |
4 |
40 |
59 |
69 |
|
9[e] |
10 |
4 |
40 |
58 |
64 |
|
10[f] |
10 |
4 |
40 |
67 |
71 |
|
11[g] |
10 |
4 |
40 |
81 |
>95 |
|
12[g,h] |
10 |
4 |
40 |
80 |
>95 |
[a] General reaction conditions: The reaction was conducted under air at 100 °C with 0.5 mmol of 1 b, and 3 mL of anisole. [b] Yields were determined by GC analysis. [c] 80 °C. [d] 2 % O2 atmosphere. [e] Addition of 2 equiv of water. [f] Addition of 4 Å molecular sieves. [g] Higher concentration (0.33 m of 1 b, 1.5 mL of anisole). [h] Addition of 1 equiv of K2CO3.