Imidazolium-oxazoline salts in ruthenium catalysed allylic substitution and cross metathesis of formed branched isomers
Résumé
Imidazolium-oxazoline chlorides have been prepared from chloroacetonitrile and used to generate bidentate mixed NHC-oxazoline ligands for ruthenium-catalyzed substitution of cinnamyl chloride by phenols. These ligands associated to [RuCp*(MeCN)3][PF6] promote allylic substitution reactions at room temperature with high regioselectivity in favour of the branched isomers giving terminal alkenes. These allylic ethers have been involved in further ruthenium-catalyzed cross metathesis reactions with electron-deficient olefins to give unsaturated esters and aldehydes.