Table 1. Evaluation of reaction conditions.

Entry	Conditions a	Yield b (%)	ee c (%)
1	Standard conditions	64	86
2	Ni(cod)2 instead of Ni(acac)2	71	76
3	NiBr2·diglyme instead of Ni(acac)2	58	80
4	5 mol% Ni(acac)2, 6 mol% L3	38	87
5	No Ni or ligand	72	0
6	0.02 M instead of 0.1 M	56	74
7	Ligand L1 instead of L3	64	74
8	Ligand L2 instead of L3	18	7
9	Ligand L4 instead of L3	24	0
10	–78 °C → rt instead of –40 °C	63	85
11	ArZnBr derived from ArMgBr	43	20
12	+3 equiv. MgBr2	13	0

^aReactions run on a 0.5 mmol scale with 3 equiv. 4-F-PhZnBr.

^bIsolated yield.

^cDetermined using chiral HPLC analysis after Pd/C-catalyzed hydrogenation to the piperidine.