Halide-promoted dioxygenolysis of a carbon-carbon bond by a copper(II) diketonate complex.
A mononuclear Cu(II) chlorodiketonate complex was prepared, characterized, and found to undergo oxidative aliphatic carbon-carbon bond cleavage within the diketonate unit upon exposure to O2 at ambient temperature. Mechanistic studies provide evidence for a dioxygenase-type C-C bond cleavage reaction pathway involving trione and hypochlorite intermediates. Significantly, the presence of a catalytic amount of chloride ion accelerates the oxygen activation step via the formation of a Cu-Cl species, which facilitates monodentate diketonate formation and lowers the barrier for O2 activation. The observed reactivity and chloride catalysis is relevant to Cu(II) halide-catalyzed reactions in which diketonates are oxidatively cleaved using O2 as the terminal oxidant. The results of this study suggest that anion coordination can play a significant role in influencing copper-mediated oxygen activation in such systems.
Department of Chemistry & Biochemistry, Utah State University , Logan, Utah 84322-0300, United States.
Caleb J
CJ
Allpress
Anna
A
Miłaczewska
Tomasz
T
Borowski
Jami R
JR
Bennett
David L
DL
Tierney
Atta M
AM
Arif
Lisa M
LM
Berreau
D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D049308:Dioxygenases / Q000737:chemistry; D006219:Halogens / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry
D006219:Halogens; D007659:Ketones; D016877:Oxidants; D002244:Carbon; D003300:Copper; D049308:Dioxygenases; D010100:Oxygen