title: Dynamic kinetic resolution of benzoins by lipase-metal combo catalysis.
abstract: The synthesis of some noncommercial racemic 1,2-diaryl-2-hydroxyethanones (benzoins) is described, optimizing the previously reported methodologies. In a further step, the kinetic resolution of these substrates is reported, obtaining conversions of around 50% and ee(p) higher than 99% in very short reaction times. As enzymatic catalyst, after screening of several enzymes, the lipase TL (from Pseudomonas stutzeri) was the most efficient, working in an organic solvent with a very low log P value, such as THF. Finally, the dynamic-kinetic resolution of different benzoins using a lipase-ruthenium-catalyzed transesterification in organic solvents is described for the first time, obtaining conversions up to 90% maintaining the excellent enantioselectivity in all cases.
authors.affiliation: Grupo de Biotransformaciones, Dpto Química Organica y Farmacéutica, Facultad Farmacia, Universidad Complutense, Plaza Ramón y Cajal s/n, E-28040 Madrid, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Hoyos
authors.forename: María
authors.initials: M
authors.lastname: Fernández
authors.forename: José Vicente
authors.initials: JV
authors.lastname: Sinisterra
authors.forename: Andrés R
authors.initials: AR
authors.lastname: Alcántara
mesh_terms: D001573:Benzoin / Q000138:chemical synthesis* / Q000302:isolation & purification*; D002384:Catalysis; D004951:Esterification; D007700:Kinetics; D008049:Lipase / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry*; D012997:Solvents
chemical_list: D008670:Metals; D012997:Solvents; D012428:Ruthenium; D008049:Lipase; D001573:Benzoin