Table 1.

Optimization conditions for forming 3^a

Entry	[Au] (1 mol%)	Solvent	Yield (%)b
1	JohnPhosAu(MeCN)SbF6	DCE	65
2	Ph3PAuCl	DCE	56
3	XPhosAuCl	DCE	48
4	SPhosAuCl	DCE	trace
5	IPrAuNTf2	DCE	29
6	AuCl3	DCE	25
7	AuCl	DCE	15
8	JohnPhosAu(MeCN)SbF6	THF	N.R.
9	JohnPhosAu(MeCN)SbF6	Acetone	N.R.
10	JohnPhosAu(MeCN)SbF6	DCM	50
11	JohnPhosAu(MeCN)SbF6	Toluene	25
12c	JohnPhosAu(MeCN)SbF6	DCE	54
13d	JohnPhosAu(MeCN)SbF6	DCE	49

^aReaction conditions: 1a (0.2 mmol), 2a (0.4 mmol), and at room temperature in the solvent (2.0 ml) for 6 h.

^bIsolated yield based on 1a.

^cThe reaction was conducted at 40 °C for 6 h.

^dThe reaction was conducted at 55 °C for 6 h.

N.R. = not reaction. JohnPhos = 2-(di-tert-butylphosphino)biphenyl, SPhos = 2-dicyclohexylphosphino-2’,6’-dimethoxybiphenyl, XPhos = 2-(dicyclohexylphosphino)-2’,4’,6’-tri-i-propyl-1,1’-biphenyl, IPr =  isopropyl, NTf₂ = bis(trifluoromethylsulfonyl)imide.