title: Titanocene-catalyzed regioselective carbomagnesation of alkenes and dienes.
abstract: A new method for regioselective carbomagnesation of alkenes and dienes has been developed by the use of a titanocene catalyst. This reaction proceeds efficiently at 0 degrees C in THF in the presence of Cp(2)TiCl(2) by the combined use of organic halides (R-X; R = alkyl, aryl and vinyl) and n-BuMgCl to afford benzyl, alpha-silylalkyl, or allyl Grignard reagents, which were trapped with various electrophiles. The present reaction involves (i) addition of carbon radicals toward alkenes or dienes in the carbon-carbon bond-forming step and (ii) transmetalation on Ti of benzyl-, alpha-silylalkyl-, or allyltitanocene with n-BuMgCl in the carbon-magnesium bond-forming step. The scope and limitations of this reaction have also been examined.
authors.affiliation: Department of Molecular Chemistry & Science and Technology Center for Atoms, Molecules and Ions Control, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Nii
authors.forename: Jun
authors.initials: J
authors.lastname: Terao
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Kambe