Table 1.

Optimization for cross-coupling with n-pentyl Grignard.

Entry	Ni catalyst (mol %)	X	Yield 2 [%][a]	ee 2 [%][b]	es 2 [%][c]	Yield 3 [%][a]	Yield 4 [%][a]
1	no Ni, no ligand	I	<5[d]	–	–	<5[d]	<5[d]
2	Ni(acac)2 (10), no ligand	I	<5[d]	–	–	<5[d]	<5[d]
3	Ni(acac)2 (10), rac-BINAP (10)	I	<5[d]	–	–	<5[d]	<5[d]
4	Ni(acac)2(10), DPEphos (10)	I	28	86	91	27	12
5	Ni(acac)2 (10), PPh3 (10)	I	8	82	86	55	14
6	Ni(acac)2 (10), dppp (10)	I	31	45	47	12	14
7	Ni(acac)2 (10), dppe (10)	I	69	66	69	<5	<5
8	Ni(acac)2 (10), dppe (15)	I	95	61	64	<5	<5
9	Ni(acac)2 (10), dppe (20)	I	0–90[e]	83[f]	87[f]	<5	<5
10	Ni(acac)2 (10), dppe (22)	I	<5[d]	–	–	<5[d]	<5[d]
11	Ni(cod)2 (10), dppe (10)	I	<5[d]	–	–	<5[d]	<5[d]
12	Ni(dppe)CI2 (10)	I	89	55	58	<5	<5
13	Ni(dppe)CI2 (10)	CI	96	51	54	5	<5
14	Ni(dppe)CI2 (10)	Br	95	91	96	<5	<5
15	Ni(dppe)CI2 (5)	Br	85	93	98	<5	<5
16	Ni(dppe)CI2 (2)	Br	97[g]	96	>99	<5	<5

^[a]Determined by ¹H NMR analysis using internal standard (PhSiMe₃).

^[b]Determined by chiral SFC.

^[c][c] Enantiospecificity (es) = ee_product/ee_{starting material} × 100%.

^[d]Recovered unreacted 1.

^[e]Reaction was irreproducible: run 1: <5% yield; run 2: <5% yield; run 3: 90% yield, 85% ee, 89% es; run 4: <5% yield; run 5: <5% yield; run 6: 84% yield, 68% ee, 72% es; run 7: 90% yield, 94% ee, 99% es;

^[f]Average of runs 3, 6, and 7.

^[g]Isolated yield.