Table 1. Optimization of reaction conditions ^a .

Entry	Metal catalyst	Conditions	Yield b (%)
1	IPrAuNTf2	DCE, 80 °C, 3 h	70
2	Ph3PAuNTf2	DCE, 80 °C, 3 h	69
3	Et3PAuNTf2	DCE, 80 °C, 3 h	54
4	Cy-JohnPhosAuNTf2	DCE, 80 °C, 3 h	71
5	BrettPhosAuNTf2	DCE, 80 °C, 12 h	27
6	Au(III) c	DCE, 80 °C, 3 h	34
7	(ArO)3PAuNTf2 d	DCE, 80 °C, 3 h	95
8	AgNTf2	DCE, 80 °C, 3 h	50
9 e	PtCl2	toluene, 80 °C, 3 h	<5
10 e	Zn(OTf)2 (10 mol%)	DCE, 80 °C, 3 h	<5
11	(ArO)3PAuNTf2 d	DCE, 60 °C, 5 h	75
12 f	(ArO)3PAuNTf2 d	DCE, 80 °C, 3 h	90

^aReaction conditions: [1a] = 0.05 M; DCE = 1,2-dichloroethane.

^bMeasured by ¹H NMR using diethyl phthalate as the internal standard.

^cDichloro(2-picolinato)gold(iii).

^d Ar = 2,4-di-tert-butylphenyl.

^e 1a was decomposed.

^f2.0 equiv. of 2a was used.