Asymmetric epoxidation of alkenes with aqueous t-BuOOH catalyzed by novel chiral complexes of chromium(III) containing tridentate Schiff-base ligands

✍ Scribed by Debabrata Chatterjee; Susan Basak; Jacques Muzart

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 361 KB
• Volume: 271
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2007.03.011

✦ Synopsis

The [Cr III (α-TDL 1 *)(bipy)(Cl)] ( 1) and [Cr III (TDL 2 *)(bipy)(Cl)] ( 2) complexes (where H 2 TDL 1 * = N-3,5-di-(t-butyl)salicylidine-dglucosamine, H 2 TDL 2 * = N-3,5-di-(tertiarybutyl)salicylidine-l-alanine, bipy = bipyridyl) have been synthesized and characterized by analytical, spectral (UV-vis and IR), molar conductivity, magnetic moment and electrochemical studies. Complexes 1 and 2 catalyzed the epoxidation of styrenes, stilbenes, 1-methylcyclohexene and 1,2-dihydronapthalene using aqueous tert-butyl hydroperoxide (t-BuOOH) as terminal oxidant. The selected alkenes were converted to their corresponding epoxides exhibiting moderate enantioselectivity at ambient temperature.