Table 5.
Metal-Catalyzed Cyclization of Aminoalkyne 22 (eq 4)
| entry | catalyst | solvent | temp (°C) |
time (h) | % yield of 78 (22) |
ref |
|---|---|---|---|---|---|---|
| 1 | 5% AuCl3 | EtOH | 75 | 48 | 10 (75) | 21 |
| 2 | 5% AuCl3/ 15% AgOTf |
MeCN | 70 | 72 | 15 (70) | 22 |
| 3 | 5% RuCl3/ 15% AgOTf |
ClCH2CH2Cl | 65 | 48 | 8 (90) | 23 |
| 4 | 5% PtCl4 | ClCH2CH2Cl | 70 | 48 | 38 (51)a | 24 |
| 5 | 5% PtCl2 | toluene | 80 | 48 | 5 (80) | 25 |
| 6 | 3% Cu(OTf)2 | CH2Cl2 | r.t. | 48 | 0 | – |
| 7 | 3% Hg(O2CCF3)2 |
MeCN | r.t. | 48 | trace | – |
| 8 | 3% Hg(OTf)2/ 15% TMU |
MeCN | r.t. | 24 | 55 (35)a | – |
| 9 | 5% Hg(OTf)2 | MeCN | r.t. | 48 | 50 (45)a | – |
| 10 | 3% Hg(OTf)2 | MeCN | 50 | 168 | 40 (50)a | – |
| 11 | 4% Hg(OTf)2 | DMSO | 100 | 48 | 10 (71) | – |
| 12 | 5% Hg(OTf)2/ 1.2 MnO2 |
MeCN | r.t. | 24 | < 1 | – |
| 13 | 10% Hg(OTf)2 | MeCN | r.t. | 6 | 96 | – |
| 14 | 10% Hg(OTf)2 | CH2Cl2 | r.t. | 24 | 95 | – |
a
The yield didn’t improve when the reaction was run a longer time.