title: New tantalum ligand-free catalyst system for highly selective trimerization of ethylene affording 1-hexene: new evidence of a metallacycle mechanism.
abstract: Mild and salt-free reduction of MCl(5) (M = Nb, Ta) has been achieved by using 3,6-bis(trimethylsilyl)-1,4-hexadiene derivatives as reducing reagents. The salt-contact-free low-valent TaCl(3) exhibits high catalytic activity for the trimerization of ethylene to 1-hexene (>1000 TOF) with excellent selectivity (>98%). This salt-free tantalum system enables us to observe new evidence for a metallacycle mechanism.
authors.affiliation: Department of Chemistry, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Rocío
authors.initials: R
authors.lastname: Arteaga-Müller
authors.forename: Hayato
authors.initials: H
authors.lastname: Tsurugi
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Saito
authors.forename: Masao
authors.initials: M
authors.lastname: Yanagawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Oda
authors.forename: Kazushi
authors.initials: K
authors.lastname: Mashima