Table 1.

Optimization of reaction conditions^a

entry	M catalyst	deviation from standard conditions	yield (%)b
1	NiCl2·dme	none	87
2	CrCl2	none	25
3	FeBr2	none	50
4	ZnCl2	none	62
5	CoCl2	none	80
6	MnCl2	none	68
7	none	none	66
8	none	no TMSCl	19
9	NiCl2·dme	no TMSCl	39
10	NiCl2·dme	NMP/HFIP (4:1), no TMSCl	67
11	NiCl2·dme	AcOH (1 equiv), no TMSCl	69
12	NiCl2·dme	Zn0 (2 equiv), no Mn0	45
13	NiCl2·dme	TDAE (1.5 equiv), no Mn0	12
14	NiCl2·dme	1 mol % catalyst	83
15	NiCl2·dme	0.1 mol % catalyst	62
16c,d	NiCl2·dme	Zn anode, RVC cathode, TBAPF6 (1 equiv), 20 mA, no Mn0 or TMSCl	76
17c,d	MnCl2	Zn anode, RVC cathode, TBAPF6 (1 equiv), 20 mA, no Mn0 or TMSCl	23

^aReactions conducted under inert atmosphere on 0.3 mmol scale.

^bDetermined by ¹H NMR versus an internal standard.

^c1.2 mmol scale.

^d1.5 equiv of 2a.