Halide-Promoted Dioxygenolysis of a Carbon鈥揅arbon Bond by a Copper(II) Diketonate Complex
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- 作者：Caleb J. Allpress ; Anna Mi艂aczewska ; Tomasz Borowski ; Jami R. Bennett ; David L. Tierney ; Atta M. Arif ; Lisa M. Berreau
- 刊名：Journal of the American Chemical Society
- 出版年：2014
- 出版时间：June 4, 2014
- 年：2014
- 卷：136
- 期：22
- 页码：7821-7824
- 全文大小：279K
- 年卷期：v.136,no.22(June 4, 2014)
- ISSN：1520-5126
文摘
A mononuclear Cu(II) chlorodiketonate complex was prepared, characterized, and found to undergo oxidative aliphatic carbon鈥揷arbon bond cleavage within the diketonate unit upon exposure to O2 at ambient temperature. Mechanistic studies provide evidence for a dioxygenase-type C鈥揅 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鈥揅l 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.