Synthesis of novel chiral 'salen-type' ferrocenyl ligands

Two novel chiral C2-symmetrical ferrocenyl 'salen-type' ligands were prepared via reaction of suitable ferrocenyldiamines with 3,5-di-tert-butylsalicylaldehyde and tested in the asymmetric epoxidation of unfunctionalized alkenes. Although the asymmetric induction was quite low, an unusually high trans/cis-epoxide ratio and high reactivity of a trans-alkene substrate were observed.