title: Development of a new sterically protecting auxiliary of the metacyclophane type and application to unsymmetrical diphosphenes, 1,3-diphosphaallene and 1,4-diphosphabutatriene.
abstract: A new bulky bromobenzene of the metacyclophane type was converted to an unsymmetrically substituted 1,4-diphos-phabutatriene whose spin-spin coupling constant (3Jpp) turned out to be larger, for the first time, than the 2Jpp value of the corresponding 1,3-diphosphaallene.
authors.affiliation: Department of Chemistry, Graduate School of Science, Tohoku University, Aoba, Sendai 980-8578, Japan.
authors.forename: Kozo
authors.initials: K
authors.lastname: Toyota
authors.forename: Akitake
authors.initials: A
authors.lastname: Nakamura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshifuji