title: Palladium-catalysed cascade ring expansion reaction of cyclobutanols that have a propargylic moiety with nucleophiles.
abstract: Cascade ring rearrangement of four-membered ring systems containing various propargylic components by a palladium catalyst is described. The reactions of cyclobutanols that have a propargylic carbonate moiety with phenols as nucleophiles produce phenoxy-induced cyclopentanones in high yields. The reactions proceed in a regio- and diastereoselective manner to afford the substituted cyclopentanones with high selectivities. Imides also act as nucleophiles to produce the imidyl-induced products. Propargylic bromide successfully reacts with sodium alkoxides to produce the corresponding products in good yields.
authors.affiliation: Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aobayama, Sendai, 980-8578, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsuzaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Nemoto
authors.forename: Masataka
authors.initials: M
authors.lastname: Ihara