Table 1. Optimization of Ni-Catalyzed Asymmetric Reductive Coupling.

entrya	ligand	additive	temp (°C)	yield 4 (%)b	yield 3a (%)b	ee 3a (%)c
1	L1	–	20	48	50	40
2	L2	–	20	33	21	57
3	L3	–	20	38	25	68
4	L4	–	20	35	26	70
5	L5	–	20	21	33	49
6	L6	–	20	20	56	87
7	L6	TFA	20	30	39	86
8	L6	TMSCl	20	26	33	73
9	L6	NaId	20	17	67	87
10	L6	TBAId	20	13	64	91
11	L6	NaId	0	8	93	93
12e	L6	NaId	0	8	69	89
13f	L6	NaId	0	0	0	–
14g	L6	NaId	0	0	0	–
15	–	NaId	0	0	0	–

^aReactions conducted under N₂ on 0.2 mmol scale for 6 h.

^bDetermined by GC vs an internal standard.

^cDetermined by SFC using a chiral stationary phase.

^d0.5 equiv.

^eZn⁰ used instead of Mn⁰.

^fNo Mn⁰.

^gNo NiCl₂(dme).