Table 1 Condition evaluation for the fully intermolecular cross-electrophile dialkylation of alkynes.


Entry	Variation from “standard conditions”^a	Yield of 4a^b(%)
1	None	66 (64), 64^c
2	w/o A1	37
3	A1 (10 mol%)	62
4	A1 (20 mol%)	59
5	A2 instead of A1	34
6	NiCl₂·DME instead of NiBr₂·DME	55
7	NiBr₂ instead of NiBr₂·DME	45
8	Ni(COD)₂ instead of NiBr₂·DME	36
9	w/o “Ni” or Zn	NR
10	w/o CeCl₃ or KI	Trace
11	ZnBr₂/ZnCl₂/TMSCl instead of CeCl₃	Trace
12	w/o H₂O	17
13	H₂O (2 equiv)	51
14	NMP instead of DMF	23
15	DMA instead of DMF	43

^aReaction was run using 0.4 mmol of 1a, 0.2 mmol of 2a, and 0.4 mmol of 3a under indicated conditions for 48 h.
^bYield was determined by GC analysis using n-dodecane as internal standard. Isolated yield is shown in the parentheses. A1 = 4-cyanopyridine, A2 = pentafluoropyridine.
^cNiBr₂·DME and A1 were presynthesized as the catalyst.

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