title: Cobalt-mediated cross-coupling reactions of primary and secondary alkyl halides with 1-(trimethylsilyl)ethenyl- and 2-trimethylsilylethynylmagnesium reagents.
abstract: [reaction: see text] This paper describes cobalt-mediated cross-coupling reactions of alkyl halides with 1-(trimethylsilyl)ethenylmagnesium bromide and 2-(trimethylsilyl)ethynylmagnesium bromide, respectively. The cobalt system allows for employing secondary as well as primary alkyl halides as the substrates. The reactions offer facile formations of alkyl-alkenyl and alkyl-alkynyl bonds. The reaction mechanism would include single-electron transfer from a cobalt complex to alkyl halide to generate the corresponding alkyl radical. The cobalt system thus enables sequential radical cyclization/alkenylation and cyclization/alkynylation reactions of 6-halo-1-hexene derivatives.
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto-daigaku Katsura, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Ohmiya
authors.forename: Hideki
authors.initials: H
authors.lastname: Yorimitsu
authors.forename: Koichiro
authors.initials: K
authors.lastname: Oshima