Table 2. Optimization of the Reaction Conditions for the Hydroarylation Reaction of 4aaa.
| entry | catalyst | mol % | temp | t (h) | yield (%)b |
|---|---|---|---|---|---|
| 1 | IPrAuNTf2 | 5 | reflux | 24 | – |
| 2 | IPrAuCl/AgOTf | 5 | reflux | 5 | 80 |
| 3 | AgOTf | 5 | reflux | 1 | 79 |
| 4 | AgOTf | 5 | reflux | 5 | 86 (83)c |
| 5 | AgOTf | 5 | rt | 24 | – |
| 6 | AgOTf | 5 | 60 | 24 | 65 |
| 7 | Bi(OTf)3 | 5 | reflux | 5 | 45 |
| 8 | Sc(OTf)3 | 5 | reflux | 5 | 28 |
| 9d | AgSbF6 | 5 | reflux | 5 | 8 |
| 10d | AgBF4 | 5 | reflux | 5 | 5< |
| 11d | AgNTf2 | 5 | reflux | 5 | 21 |
| 12 | TfOH | 5 | reflux | 5 | 40 |
| 13 | TfOH | 1 | reflux | 5 | 36 |
| 14d | TfOH | 0.5 | reflux | 24 | 19 |
a
Reaction conditions: 4aa (0.1 mmol) in 1,2-dichloroethane (1 mL).
b
Determined by 1H NMR using CH2Br2 as an internal standard.
c
Yield after column chromatography in parentheses.
d
No full conversion of 4aa was achieved.