Entry Variations from standard conditions Conv.% of 1ab Yield% of 3aab (r.r.c; l:bd)
1 none >99 90, 88e (>99:1; >99:1)
Different nickel catalysts instead of Ni(DME)Cl2 Different nickel catalysts instead of Ni(DME)Cl2 Different nickel catalysts instead of Ni(DME)Cl2 Different nickel catalysts instead of Ni(DME)Cl2
2 Ni(DME)Br2 54 49 (>99:1; >99:1)
3 Ni(TMEDA)Cl2 >99 86 (99:1; >99:1)
4 Ni(acac)2 >99 83 (95:5; >99:1)
5 Ni(OAc)2·4H2O >99 84 (98:2; >99:1)
6 NiCl2·6H2O >99 82 (96:4; >99:1)
7 No Ni(DME)Cl2 0 N.D.
Different bases instead of t-BuOK Different bases instead of t-BuOK Different bases instead of t-BuOK Different bases instead of t-BuOK
8 EtOK >99 83 (95:5; >99:1)
9 KOH 21 18 (90:10; >99:1)
10 KF 0 N.D.
11 t-BuONa 65 59 (>99:1; >99:1)
12 t-BuOLi 5 2 (>99:1; >99:1)
13 No activator 0 N.D.
Different solvents instead of THF Different solvents instead of THF Different solvents instead of THF Different solvents instead of THF
14 CH3CN >99 88 (99:1; >99:1)
15 DME >99 90 (>99:1; >99:1)
16 CH2Cl2 0 N.D.
Different temperatures instead of -30 ºC Different temperatures instead of -30 ºC Different temperatures instead of -30 ºC Different temperatures instead of -30 ºC
17 under -40 ºC 0 N.D.
18 under 25 ºC 84 49 (90:10; >99:1)