Table 1. Gold-catalyzed synthesis of 8a: selected optimization ^a .

Entry	Acid	Time	Yield b
1	2.1 equiv. MsOH	24 h	47% c
2	1.3 equiv. MsOH, 1.1 equiv. TFA	20 h	63%
3	1.3 equiv. MsOH, 1.1 equiv. TFA	6 h	69% d
4	1.3 equiv. MsOH, 1.1 equiv. TFA	8 h	51% e
5	1.3 equiv. MsOH, 1.1 equiv. TFA	8 h	74% f

^a[10a] = 0.1 M (0.12 mmol).

^bIsolated yield after flash chromatography.

^c39% starting material 10a was recovered.

^d200 mg scale reaction, 3% AgOTf was added as an additive.

^e1 g scale reaction, 5% PPh₃AuNTf₂, 2% AgOTf as an additive.

^f3 g scale reaction, 5% PPh₃AuNTf₂, 2% AgOTf as an additive, 1 equiv. AgOTf was added with NaHCO₃ (s, aq.) to facilitate the cyclization.