TY - JOUR
T1 - Precatalyst separation paradigms
T2 - Alkane functionalization in water utilizing in situ formed [Fe2O(η1-H2O)(η1- OAc)(TPA)2]3+, embedded in surface-derivatized silica, as an MMO model, and fluorous biphasic catalysis for alkane, alkene, and alcohol oxidation chemistry
AU - Fish, Richard H.
AU - Rabion, Alain
AU - Neimann, Karine
AU - Neumann, Ronny
AU - Vincent, Jean Marc
AU - Contel, Maria
AU - Izuel, Cristina
AU - Villuendas, Pedro R.
AU - Alonso, Pablo J.
N1 - Funding Information:
The derivatized silica research was generously supported by Grant No. 95-00076 from the United States– Israel Binational Science Foundation (BSF), Jerusalem, Israel to RN and RHF. RN and RHF also thank BSF for travel funds to each others institutions. The FBC studies at LBNL were generously supported by a gift grant to RHF from Elf Aquitaine Inc and the Department of Energy under contract No. DE-AC03-76SF00098. The University of Zaragoza authors would like to thank the MCYT for financial support (BQU2002-04090-C02-01). M.C. wishes to thank the MCYT – Universidad de Zaragoza for the Research Contract ‘‘Ramón y Cajal’’. RHF also wishes to thank the Ministerio de Educación y Cultura, Madrid, Spain, for a Visiting Professorship in 2000 at the University of Zaragoza.
PY - 2005/3
Y1 - 2005/3
N2 - Two new paradigms for separating the homogeneous catalyst from the substrate and products of oxidation were reviewed. The first example demonstrated the functionalization in water of hydrophobic substrates, i.e., hydrocarbons, with methane monooxygenase biomimetic complexes embedded in a derivatized surface silica system using tert-butyl hydroperoxide/O2 as the oxidants. For example, cyclohexane was oxidized to a mixture of cyclohexanone, cyclohexanol, and cyclohexyl-tert-butyl peroxide, in a ratio of ∼ 3:1:2. The balance between polyethylene oxide and polypropylene oxide, tethered on the silica surface, was crucial for maximizing the catalytic activity. The mechanism for the silica-based catalytic assembly occurred via the Haber-Weiss process. The second precatalyst separation paradigm, the use of the fluorous solvents, which was predicted on solubilizing the precatalyst in a fluorocarbon solution, allowed the functionalization of alkanes and alkenes, while selective oxidation of alcohols to aldehydes was also possible; both precatalyst and product were in separate solvent phases.
AB - Two new paradigms for separating the homogeneous catalyst from the substrate and products of oxidation were reviewed. The first example demonstrated the functionalization in water of hydrophobic substrates, i.e., hydrocarbons, with methane monooxygenase biomimetic complexes embedded in a derivatized surface silica system using tert-butyl hydroperoxide/O2 as the oxidants. For example, cyclohexane was oxidized to a mixture of cyclohexanone, cyclohexanol, and cyclohexyl-tert-butyl peroxide, in a ratio of ∼ 3:1:2. The balance between polyethylene oxide and polypropylene oxide, tethered on the silica surface, was crucial for maximizing the catalytic activity. The mechanism for the silica-based catalytic assembly occurred via the Haber-Weiss process. The second precatalyst separation paradigm, the use of the fluorous solvents, which was predicted on solubilizing the precatalyst in a fluorocarbon solution, allowed the functionalization of alkanes and alkenes, while selective oxidation of alcohols to aldehydes was also possible; both precatalyst and product were in separate solvent phases.
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U2 - 10.1007/s11244-005-2890-9
DO - 10.1007/s11244-005-2890-9
M3 - Article
AN - SCOPUS:18244365339
VL - 32
SP - 185
EP - 196
JO - Topics in Catalysis
JF - Topics in Catalysis
SN - 1022-5528
IS - 3-4
ER -