Table 1.

Reaction optimization^a.

Entry	Deviation from standard conditions	Yield, %	3a:4a
1	No	89 (82)b	27:1
2	No Et3SiH	6	4:1
3	Zn instead of Et3SiH	35	12:1
4	ZnMe2, MeMgBr instead of Et3SiH	Trace	–
5	KF, Na2CO3, Cs2CO3, NaOH instead of LiOH	Trace	–
6	No TBAB	8	2:1
7	NiCl2 instead of NiI2	Trace	–
8	NiBr2 instead of NiI2	46	21:1
9	Ni(COD)2, no Et3SiH	12	2:1
10	L1	28	2:1
11	L2	81	51:1
12	L3	78	35:1
13	L4	76	1:77
14	NiI2/BC (5 mol%)	72	19:1
15	60 °C, 24 h	71	8:1
16	60 °C, no Et3SiH	10	6:1

^aStandard conditions: NiI₂ (15.6 mg, 0.05 mmol, 10 mol%), BC (18.0 mg, 0.05 mmol, 10 mol%), Et₃SiH (20 μL, 0.13 mmol, 25 mol%), 1a (145.0 mg, 0.5 mmol, 1.0 equiv), 2a (127.5 mg, 0.75 mmol, 1.5 equiv), LiOH (29.9 mg, 1.25 mmol, 2.5 equiv), TBAB (161.2 mg, 0.5 mmol, 1.0 equiv), DMA (4 mL). Yields were determined by GC with 1,3,5-trimethoxybenzene as the internal standard

^bIsolated yield