Aerobic oxidation of pinacol by vanadium(V) dipicolinate complexes: evidence for reduction to vanadium(III).
The reactivity of vanadium complexes bearing the ligand dipicolinic acid (H(2)dipic) with alcohols has been explored. Dipic vanadium complexes are able to catalyze the aerobic oxidative C-C bond cleavage of pinacol. Reaction under anaerobic conditions allowed for isolation of a V(III) mu-oxo dimer, supporting the involvement of V(III) in aerobic oxidation reactions. Stoichiometric oxidation of unactivated aliphatic alcohols has also been observed, with oxidation of cyclobutanol producing cyclobutanone in 93% yield. The absence of ring-opening products in this reaction provides further support for the involvement of V(III) intermediates.
Hanson
Susan K
SK
Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Baker
R Tom
RT
Gordon
John C
JC
Scott
Brian L
BL
Sutton
Andrew D
AD
Thorn
David L
DL
D000332:Aerobiosis; D002072:Butylene Glycols / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010848:Picolinic Acids / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017968:Vanadium Compounds / Q000138:chemical synthesis / Q000737:chemistry*
D002072:Butylene Glycols; D008024:Ligands; D010848:Picolinic Acids; D017968:Vanadium Compounds; C004860:dipicolinic acid