title: The Mg-oppenauer oxidation as a mild method for the synthesis of aryl and metallocenyl ketones.
abstract: Magnesium alkoxides undergo a hydride-transfer oxidation with benzaldehyde as the oxidant. This magnesium variant of the Oppenauer oxidation was used for the synthesis of polyfunctional biaryl ketones. LiCl was found to promote this reaction by enhancing the solubility of magnesium alkoxides. This mild oxidation method was especially useful for preparing ketones bearing a metallocenyl unit as well as various new ferrocenyl ketones and tricarbonylchromium complexes. This last class of ketones was reduced with the CBS catalyst (CBS=Corey-Bakshi-Shibata, diphenyl oxazaborolidine) to chiral benzhydrol complexes with high enantioselectivity enabling an asymmetric synthesis of electron-rich or -poor benzhydryl alcohols (up to 94 % ee).
authors.affiliation: Universität Zürich, Organisch-chemisches Institut, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Kloetzing
authors.forename: Arkady
authors.initials: A
authors.lastname: Krasovskiy
authors.forename: Paul
authors.initials: P
authors.lastname: Knochel
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D000438:Alcohols; D000447:Aldehydes; D005296:Ferrous Compounds; D007659:Ketones; D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; C013108:metallocene; D008274:Magnesium