Nickel-catalyzed cross-coupling reaction of Grignard reagents with alkyl halides and tosylates: Remarkable effect of 1,3-butadienes

Article abstract of DOI:10.1021/ja025828v

A new method for the cross-coupling reaction of Grignard reagents with alkyl chlorides, bromides, and tosylates has been developed by the use of a nickel catalyst in the presence of a diene as an additive. This reaction proceeds efficiently at 0-25 °C in THF using primary and secondary alkyl and aryl Grignard reagents. Nickel complexes bearing no phosphine ligands, such as NiCl₂, Ni(acac)₂, and Ni(COD)₂, afford the coupling products in good yields, whereas NiCl₂(PPh₃)₂ and NiCl₂(dppp) were less effective. 1,3-Butadiene shows the highest activity as an additive for the present coupling reaction. A plausible reaction pathway was proposed. Copyright

Full text of DOI:10.1021/ja025828v

Supporting Information
Nickel-Catalyzed Cross-Coupling Reaction of Grignard Reagents with Alkyl Halides and
Tosylates: Remarkable Effect of 1,3-Butadienes
Jun Terao, Hideyuki Watanabe, Aki Ikumi, Hitoshi Kuniyasu, and Nobuaki Kambe*
Department of Molecular Chemistry & Frontier Research Center, Graduate School of Engineering,
Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871.
Typical Experimental Procedures and Analytical Data of Products.
1-Bromo-4-hexylbenzene
A
50
mL
pyrex
glass
vessel
containing
a
magnetic
stirring
bar,
n
1-bromo-4-(2-bromoethyl)benzene (528 mg, 2 mol) and BuMgCl (0.9 M in THF, 2.89 mL, 2.6
mmol) was cooled at -78 oC. Then 1,3-butadiene (4.48 ml at 20 °C under 1 atm) was introduced by
a syringe into the vessel. To the mixture was added a catalytic amount of NiCl2 (2.6 mg, 0.02 mmol)
and the solution was warmed to 0 °C by an ice-water bath and stirred for 30 min. A saturated
aqueous NH4Cl solution (10 mL) was added, and the product was extracted with ether (10 mL),
dried over MgSO4, and evaporated to give a colorless product (100% GC yield). IR (neat): 2956,
2928, 2856, 1488, 1466, 1072, 1012 cm-1; 1H NMR (400 MHz, CDCl3): δ=7.38 (d, J=8.0, 2H), 7.04
(d, J=8.0, 2H), 2.55 (t, J=7.6 Hz, 2H), 1.59-1.56 (m, 2H), 1.31-1.28 (m, 6H), 0.88 (t, J=6.8, 3H);
13C NMR (100 MHz, CDCl3) δ=141.7, 131.1, 130.0, 119.1, 35.5, 31.8, 31.4, 29.0, 22.7, 14.2; Anal.
calcd for C12H17Br: C, 59.76; H, 7.11. found: C, 60.02; H, 7.15.
n-Nonylcyclopropane
n
A mixture of cyclopropylmethyl bromide (270 mg, 2 mmol) and OctMgCl (1.0 M in THF, 2.6
mL, 2.6 mmol) was cooled to -78 °C and 1,3-butadiene (4.48 mL at 20 °C under 1 atm) was
introduced. After adding NiCl2 (2.6 mg, 0.02 mmol) at -78 °C, the solution was stirring for 30 min
at 0 °C. Similar workup as mentioned above afforded a colorless crude product (87% GC yield). IR
1
(neat): 2924, 2853, 1654, 1458, 1320, 1013 cm-1; H NMR (400 MHz, CDCl3): δ=1.39-1.31 (m,
2H), 1.29-1.22 (m, 12H), 1.19 (q, J=7.1 Hz, 2H), 0.88 (t, J=6.8 Hz, 3H), 0.70-0.59 (m, 1H),
0.40-0.32 (m, 2H), -0.02 (m, 2H); 13C NMR (100 MHz, CDCl3): δ=34.9, 32.1, 29.9, 29.8, 29.7, 29.5,
22.9, 14.3, 11.1, 4.6.