title: Reversal of selectivity in gold-catalyzed cyclizations of 3,3-disubstituted 1,4-diynes.
abstract: A general synthetic access to 3,3-disubstituted 1,4-diynes bearing a quaternary carbon center from acetylacetone was developed. The compounds were cyclized to the corresponding enol ethers by cationic gold complexes. The reactions occur in complete exo-selectivity in contrast to compounds incorporating an alkoxy substituent in the 3-position. A mechanistic rationale for this reversal of selectivity is provided.
authors.affiliation: Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Roman
authors.initials: R
authors.lastname: Rüttinger
authors.forename: Juliane
authors.initials: J
authors.lastname: Leutzow
authors.forename: Michael
authors.initials: M
authors.lastname: Wilsdorf
authors.forename: Kristina
authors.initials: K
authors.lastname: Wilckens
authors.forename: Constantin
authors.initials: C
authors.lastname: Czekelius