Table 1. Nickel-catalyzed reductive coupling of 1a with 2a ^a .

Entry	Ligand	Solvent	Yield (%)
1	L1	DMF	20
2	L2	DMF	18
3	L3	DMF	32
4	L4	DMF	0
5	PPh3	DMF	34
6	P(4-MePh)3	DMF	16
7	P(2-MePh)3	DMF	0
8	P(4-FPh)3	DMF	50
9	P(4-CF3Ph)3	DMF	58
10	P(4-CF3Ph)3	DMA	52
11	P(4-CF3Ph)3	DMSO	73 (79) b
12	P(4-CF3Ph)3	DMSO/DMA 1 : 1	68 (73) b
13	P(4-CF3Ph)3	DMSO/DMF 1 : 1	70 (75) b , (82) c
14 d	P(4-CF3Ph)3	DMSO/DMF 1 : 1	0
15 e	P(4-CF3Ph)3	DMSO/DMF 1 : 1	0

^aSubstrates 1a (0.2 mmol), monodentate ligand (30 mol%), or bidentate ligand (15 mol%) were used and reacted for 24 h; yields were determined by ¹H NMR using anisole as an internal standard.

^bYields are isolated yields.

^c 1a (4 mmol, 0.976 g) was used; isolated yield.

^dNo Ni catalyst.

^eNo Mn.