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Notes and references
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Fig. 11 Reaction mechanism of Fe(III) promoted oxidation.
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4. Conclusions
In summary, a novel magnetic core–shell Fe3O4@P4VP@FeCl3
structure was designed, prepared and fully characterized. The
iron(III) immobilized core–shell microspheres were composed
by a magnetic Fe3O4 core and a P4VP middle layer. Taking
advantage of active iron(III) catalytic site, the magnetic
composite microspheres were utilized as an efficient catalyst for
the selective aerobic oxidation of alcohols. A variety of alcohol
substrates were tolerated under our optimized conditions at
only 2 mol% catalyst loading. In addition, benzylic oxidation of
hydrocarbon compounds was also carried out using the Fe3-
O4@P4VP@FeCl3 catalyst and tBuOOH oxidant. The initial
catalytic activity of the Fe3O4@P4VP@FeCl3 catalyst was
retained aer at least ve consecutive reaction cycles. A hot
ltration test suggested low leaching of iron into the solution.
Further applications of the various heterogeneous core–shell
catalysts are currently under investigation.
Conflicts of interest
There are no conicts to declare.
Acknowledgements
This work is supported by Beijing Natural Science Foundation
(2172037) and National Natural Science Foundation of China
(No. 51503016). P. Y. thanks the State Key Laboratory of
Chemical Resource Engineering and Y. L. thanks the
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Chem. Commun., 2014, 50, 9679; (b) T. Lu, Z. Du, J. Liu, H. Ma
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