Alkene metathesis catalysed by /AlCl2Et

Article abstract of DOI:10.1016/0022-328X(89)85225-8

/AlCl2Et mixtures promote metathesis of cis-2-pentene to give 2-butene and 3-hexene.For diene=norbornadiene the reaction is catalytic, and is accompanied by cis to trans isomerisation of the 2-pentene, whereas for diene=1,5-cyclooctadiene or cyclooctatetraene the metathesis is essentially stoicheiometric.The same complexes catalyze the metathesis of trans-2-pentene to give 2-butene and 3-hexene, but at approximately twice the rate observed for the cis-alkene. /AlCl2Et mixtures also catalyse the metathesis of 1,7-octadiene to give cyclohexene and ethene.The intermediacy of metal carbene derivatives in such reactions is supported by the reactions of with alkylating agents SiMe4 and MeMgBr which give methane, whereas and AlCl2Et in the absence of alkenes gave virtually stoicheiometric amounts of ethane.