ELECTRONIC EFFECTS OF BIS(2-ARYL-4,5,6,7-TETRAHYDROINDENYL)TITANOCENEDICHLORIDES ON THE CATALYTIC EPOXIDATION OF TRANS-3-HEXENE

The catalytic epoxidation of trans-3-hexene with electronically differ ent bis(2-aryl-4,5,6,7-tetrahydroindenyl)titanium dichloride complexes in the presence of stoichiometric tert-butylhydroperoxide has been st udied. The results show that bath electron donating (4-methoxyphenyl a nd 4-methylphenyl) and withdrawing (4-bromophenyl) groups on the 2-pos ition of 4,5,6,7-tetrahydroindene produce an enhancement in the number of turnovers of epoxide formed during 15 h at 80 degrees C when compa red to the 2-phenyl substituted complex. The facile preparation and pu rification of these previously unreported ligands and the correspondin g titanocene complexes, and the results of the catalytic epoxidation o f trans-3-hexene are described.