title: Nickel-catalyzed cross-coupling reaction of grignard reagents with alkyl halides and tosylates: remarkable effect of 1,3-butadienes.
abstract: 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 degrees 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.
authors.affiliation: Department of Molecular Chemistry & Frontier Research Center, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871. Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Terao
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Aki
authors.initials: A
authors.lastname: Ikumi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kuniyasu
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Kambe