Table 2.
Screening for the HCS in HEP/water/TMG system conditions.
|
| ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
Entry |
2 |
1 [equiv.] |
PdII |
Ligand [mol %] |
CuX [mol %] |
T [°C] |
t [h] |
Conv.[a] [%] |
3/5[a] |
3 yield[b] [%] |
|
1 |
2 a |
1.05 |
Pd(PPh3)2Cl2 |
– |
CuI (1) |
30 |
0.5 |
>99 |
>99 : 1 |
97[c] |
|
2 |
2 a |
1.05 |
Pd(PPh3)2Cl2 |
– |
CuI (1) |
30 |
0.5 |
>99 |
>99 : 1 |
95 |
|
3 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
CuI (1) |
30 |
0.5 |
>99 |
>99 : 1 |
95[d] |
|
4 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPMS (4) |
CuI (1) |
30 |
1 |
>99 |
>99 : 1 |
92 |
|
5 |
2 a |
1.5 |
Pd(CH3CN)2Cl2 |
TPPDS (4) |
CuI (1) |
30 |
1 |
>99 |
>99 : 1 |
95 |
|
6 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
CuI (0.25) |
30 |
0.5 |
>99 |
>99 : 1 |
93 |
|
7 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
CuI (0.1) |
30 |
1 |
>99 |
>99 : 1 |
95 |
|
8 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
CuBr (0.25) |
30 |
0.5 |
>99 |
>99 : 1 |
95 |
|
9 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
CuCl (0.25) |
30 |
0.5 |
>99 |
>99 : 1 |
92 |
|
10 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
– |
60 |
1 |
>99 |
>99 : 1 |
95 |
|
11 |
2 a |
1.05 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
– |
30 |
14 |
>99 |
>99 : 1 |
97 |
|
12 |
2 a |
1.5 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
– |
30 |
3 |
>99 |
>99 : 1 |
94 |
|
13 |
2 b |
1.5 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
– |
60 |
4 |
>99 |
88 : 12 |
91 |
|
14 |
2 b |
1.2 |
Pd(CH3CN)2Cl2 |
TPPTS (4) |
– |
60 |
4 |
>99 |
>99 : 1 |
96[e] |
|
15 |
2 b |
1.5 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
– |
60 |
2 |
>99 |
90 : 10 |
95 |
|
16 |
2 b |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
– |
60 |
2 |
>99 |
>99 : 1 |
93[e] |
|
17 |
2 b |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
– |
30 |
24 |
80 |
>99 : 1 |
– |
|
18 |
2 b |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
CuI (1) |
30 |
2 |
>99 |
>99 : 1 |
94 |
|
19 |
2 b |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
CuI (0.1) |
30 |
3 |
>99 |
>99 : 1 |
97 |
|
20 |
2 c |
1.2 |
Pd(CH3CN)2Cl2 |
sSPhos (4) |
– |
60 |
1 |
>99 |
90 : 10 |
92 |
|
21 |
2 c |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (6) |
– |
60 |
3 |
>99 |
>99 : 1 |
92[e] |
|
22 |
2 c |
1.05 |
Pd(CH3CN)2Cl2 |
sSPhos (6) |
CuI (0.25) |
30 |
4 |
>99 |
>99 : 1 |
95 |
[a] Determined by HPLC. [b] The products were isolated after cyclohexane extraction and purification by flash chromatography only if the conversion exceeded 90 %. [c] The reaction was performed under anhydrous conditions. [d] The reaction was performed also using the recovered catalyst kept for one week under nitrogen, obtaining the same reaction yield. [e] Phenylacetylene 1 was added using a syringe pump over the reaction time.