Table 2 Condition optimization for enantiospecific reductive alkylative cyclization of 1,6-enynes^a

Entry	Ligand	Solvent	Yield (%) of 7aa^b	ee/es (%) of 7aa^c
1	L9	DMA	56	5/5
2	L10	DMA	60	80/81
3^d	L10	DMA	38	52/53
4^e	L10	DMA	48	67/68
5	L10	THF	trace	–
6	L10	DMF	49	75/76
7	L10	DMSO	trace	–
8	L10	DMA/THF(1/2)	78	86/87
9	L11	DMA/THF(1/2)	34	46/46
10	L12	DMA/THF(1/2)	77	84/85
11	L13	DMA/THF(1/2)	60	29/29
12	L14	DMA/THF(1/2)	trace	–
13	L15	DMA/THF(1/2)	78	91/92
14	L16	DMA/THF(1/2)	63	84/85
15	L17	DMA/THF(1/2)	43	8/8
16	L18	DMA/THF(1/2)	trace	–
17^f	L15	DMA/THF(1/2)	21	91/92
18^g	L15	DMA/THF(1/2)	trace	–
19	-	DMA/THF(1/2)	trace	–

^aReaction conditions: E-4a (0.1 mmol, 99% ee), 5a (0.2 mmol), Ni(ClO₄)₂·6H₂O (10 mol %), ligand (20 mol %), Mn dust (0.3 mmol), NaI (0.05 mmol) in a sealed tube in 2 mL solvent at 20 ^oC, unless noted otherwise.
^bIsolated yields after flash chromatography.
^cThe ee values were determined by HPLC analysis with a chiral column.
^dThe reaction was performed at 0 ^oC.
^eThe reaction was performed at 40 ^oC.
^fWithout NaI.
^gWithout Mn⁰.

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