title: Generation of reactive species by one-electron reduction of Fischer-type carbene complexes of group 6 metals and their use for carbon-carbon bond formation.
abstract: Carbon-carbon bond-forming reactions mediated by one-electron reduction of Fischer-type carbene complexes of Group 6 metals were investigated. In the case of aryl- or silylcarbene complexes of tungsten, the anion radical species generated by one-electron reduction smoothly underwent addition reaction to ethyl acrylate. One-electron reduction of alpha,beta-unsaturated carbene complexes afforded biscarbene complexes by dimerization of the corresponding anion radical species at the position gamma to the metal center. In contrast, one-electron reduction of chromium phenyl- or alkylcarbene complexes gave, via carbonyl insertion, alpha-methoxyacylchromate complexes, which further underwent conjugate addition to various electron-poor olefins to give the corresponding alpha-methoxyketones.
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Fuchibe
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Iwasawa