title: New, improved procedure for the synthesis of structurally diverse N-spiro C2-symmetric chiral quaternary ammonium bromides.
abstract: Selective, direct ortho magnesiation of (S)-2,2'-bis(isopropoxycarbonyl)-1,1'-binaphthyl (6) has been achieved under mild conditions, using magnesium bis(2,2,6,6-tetramethylpiperamide) [Mg(TMP)(2)]. In combination with the subsequent reaction with the appropriate electrophiles, bromine and iodine, this method constitutes a key step in establishing a new and concise synthetic route to a wide variety of N-spiro C(2)-symmetric chiral quaternary ammonium bromides of type 1.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ooi
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Uematsu
authors.forename: Keiji
authors.initials: K
authors.lastname: Maruoka