Table 1.

Optimization of the reaction conditions^a,b.

Entry	[Ni]	Ligand	Reductant	Solvent	3b-Yield (%)b
1	Ni(acac)2	L1	Mn	DMF	>99
2	Ni(PPh3)2Cl2	L1	Mn	DMF	78
3	NiCl2	L1	Mn	DMF	64
4	NiI2	L1	Mn	DMF	75
5	NiBr2	L1	Mn	DMF	85
6	Ni(acac)2	L2	Mn	DMF	>99
7	Ni(acac)2	L3	Mn	DMF	75
8	Ni(acac)2	L4	Mn	DMF	98
9	Ni(acac)2	L5	Mn	DMF	>99
10	Ni(acac)2	L6	Mn	DMF	85
11	Ni(acac)2	L7	Mn	DMF	90
12	Ni(acac)2	L8	Mn	DMF	99
13	Ni(acac)2	L1	Mn	DMA	20
14	Ni(acac)2	L1	Mn	MeCN	0
15	Ni(acac)2	L1	Mn	DMSO	0
16	Ni(acac)2	L1	Zn	DMF	Trace

^aReaction conditions: 1b (0.2 mmol, 1.0 equiv.), 2a (0.24 mmol, 1.2 equiv.), Ni(acac)₂ (5.0 mol%), ligand (10 mol%); Mn (0.3 mmol, 1.5 equiv.), DMF (1 mL); N₂ atmosphere; 40 °C; 24 h.

^bYields were determined by GC with biphenyl as the internal standard.