title: Dinuclear chiral vanadium catalysts for oxidative coupling of 2-naphthols via a dual activation mechanism.
abstract: This review describes our recent efforts in the development of chiral dinuclear vanadium complexes that work as dual activation catalysts for the oxidative coupling of 2-naphthols. The dinuclear vanadium(iv) complex (R(a),S,S)- was prepared by complexation of VOSO(4) with the Schiff base derived from (R)-3,3'-diformyl-2,2'-dihydroxy-1,1'-binaphthyl () and (S)-tert-leucine. Since the dinuclear vanadium(iv) complex was found to be readily oxidized to afford a corresponding vanadium(v) species during preparation in air, a new synthetic procedure using VOCl(3) has been applied towards dinuclear vanadium(v) complexes (R(a),S,S)- and (R(a),S,S)-. To the best of our knowledge, (R(a),S,S)-, and show considerably higher catalytic activity than previously reported vanadium complexes for the oxidative coupling of 2-naphthols.
authors.affiliation: The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka, Ibaraki-shi, Osaka 567-0047, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Takizawa
authors.forename: Tomomi
authors.initials: T
authors.lastname: Katayama
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sasai