title: Efficient alcoholysis of 5,6-dihydro-1,10-phenanthroline-5,6-epoxide with ytterbium(III) triflate and subsequent enantioselective transesterification with lipases.
abstract: New 5,6-dihydro-1,10-phenanthroline derivatives were prepared in high yield via ytterbium(III) triflate-catalyzed alcoholysis of the corresponding epoxide. Enzymatic transesterifications of racemic alkoxy alcohols afforded enantioselective separations with up to 99% ee. The lipase derived from Burkholderia cepacia (PSCI) was the most efficient, with E-values of up to 200. The steric effect of substituents in the 6-position on reaction time and enantioselectivities was assessed.
authors.affiliation: Department of Chemistry, Western Michigan University, 3425 Wood Hall, Kalamazoo, MI 49008-5413, USA.
authors.forename: Elke
authors.initials: E
authors.lastname: Schoffers
authors.forename: Lars
authors.initials: L
authors.lastname: Kohler