title: Direct episulfidation of alkenes and allenes with elemental sulfur and thiiranes as sulfur sources, catalyzed by molybdenum oxo complexes.
abstract: The molybdenum oxo complexes 1a and 1b catalyze efficiently the sulfur transfer to a series of alkenes 4 and allenes 6, for which elemental sulfur, phenylthiirane, or methylthiirane have been employed as sulfur sources to afford the corresponding episulfides 5 and 7. The most effective catalytic episulfidation system to date is the combination of the dithiophosphate-ligated oxo complex 1b and phenylthiirane (Ibeta). This metathesis process is efficient enough to convert usually reluctant alkenes (cyclopentene, cycloheptene, Z-cyclooctene, Z-cyclononene, E-cyclodecene, norbornene, and even bicyclopropylidene) to their episulfides in good yields under mild conditions. The direct catalytic sulfuration of allenes (cyclonona-1,2-diene, cyclonona-1,2,5-triene, cyclodeca-1,2-diene, and 2,4-dimethylpenta-2,3-diene) to their labile methylenethiiranes is unprecedented.
authors.affiliation: Contribution from the Institut für Organische and Anorganische Chemie der Universität Würzburg, Am Hubland, Germany. adam@chemie.uni-wuerzburg.de
authors.forename: Waldemar
authors.initials: W
authors.lastname: Adam
authors.forename: Rainer M
authors.initials: RM
authors.lastname: Bargon
authors.forename: Wolfdieter A
authors.initials: WA
authors.lastname: Schenk