title: Preparation of multisubstituted allenes from allylsilanes.
abstract: [reaction: see text] A three-step route of converting allylsilanes to functionalized allenes was developed. Thermal decomposition of 1,1-dibromo-2-(silylmethyl)cyclopropanes, which were quantitatively prepared by treatment of allylsilane derivatives with CHBr3/KO(t)Bu, afforded substituted 2-bromo-1,3-butadienes with elimination of bromosilanes. The Pd-catalyzed reaction of the bromodienes with soft nucleophiles gave the allene derivatives. Previously inaccessible tri- and tetrasubstituted allenes can be prepared by this method as well.
authors.affiliation: Catalysis Research Center and Graduate School of Pharmaceutical Sciences, Hokkaido University, and SORST, Japan Science and Technology Agency, Kita-ku, Sapporo 001-0021, Japan. ogasawar@cat.hokudai.ac.jp
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ogasawara
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Ge
authors.forename: Koichi
authors.initials: K
authors.lastname: Uetake
authors.forename: Liyan
authors.initials: L
authors.lastname: Fan
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Takahashi