title: Chemoselective metal-free aerobic alcohol oxidation in lignin.
abstract: An efficient organocatalytic method for chemoselective aerobic oxidation of secondary benzylic alcohols within lignin model compounds has been identified. Extension to selective oxidation in natural lignins has also been demonstrated. The optimal catalyst system consists of 4-acetamido-TEMPO (5 mol %; TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) in combination with HNO3 and HCl (10 mol % each). Preliminary studies highlight the prospect of combining this method with a subsequent oxidation step to achieve C-C bond cleavage.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Rahimi
authors.forename: Ali
authors.initials: A
authors.lastname: Azarpira
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
authors.forename: John
authors.initials: J
authors.lastname: Ralph
authors.forename: Shannon S
authors.initials: SS
authors.lastname: Stahl
mesh_terms: D000332:Aerobiosis; D019905:Benzyl Alcohol / Q000737:chemistry*; D001639:Bicarbonates / Q000737:chemistry; D001704:Biopolymers; D002384:Catalysis; D006851:Hydrochloric Acid / Q000737:chemistry; D007202:Indicators and Reagents; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D010084:Oxidation-Reduction
chemical_list: D001639:Bicarbonates; D001704:Biopolymers; D007202:Indicators and Reagents; D008670:Metals; D008031:Lignin; D019905:Benzyl Alcohol; D006851:Hydrochloric Acid