Abstract
Intramolecular metathesis of various diallyl compounds containing the O, S, Si or P hetero element was achieved with good yields by using the cyclometallated carbene complex
(OAr)(CHMe
3)Cl(OEt
2). Unsubstituted diallyl ether is converted into 2,5-dihydrofuran; diallyl sulfide is converted into 2,5-dihydrothiophen; diallyl-phenyl phosphine is converted into phenyl-2,5-phospholen and diallyl dimethyl- or diphenyl-silanes are converted into the corresponding silacyclopentenes. Metathesis reaction of methyl-substituted diallyl-sulfides shows that steric effects are very important. These steric effects are also well seen by addition of di-
n-propyl or di-
i-propyl sulfides during the metathesis reaction of diallyl sulfide. Indeed, only the former compound inhibit the reaction, showing that there is an important steric crowding around the tungsten atom.