title: Transannular [4 + 2] Cycloaddition Reactions of Cobalt-Complexed Macrocyclic Dienynes.
abstract: The first transannular [4 + 2] cycloaddition reactions of macrocyclic dicobalt hexacarbonyl-dienyne complexes were demonstrated. Complexes were conveniently prepared through palladium(II)-catalyzed intramolecular oxidative cyclization of bis(vinylboronate esters) followed by complexation with dicobalt octacarbonyl. Transannular [4 + 2] cycloaddition reactions of the complexes occurred at lower temperatures and shorter times than transannular Diels-Alder reactions of metal-free dienynes. Intermolecular control reactions confirmed the effect of cobalt complexation on [4 + 2] cycloaddition reactions of unactivated alkynes and dienes.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States.
authors.forename: Sedef
authors.initials: S
authors.lastname: Karabiyikoglu
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Merlic