Abstract
Silica-supported 4-OH-2,2,6,6-tetramethylpiperidyl-1-oxy/NOx (4-OH-TEMPO was immobilized on the surface of silica using the sol-gel method, and then it adsorbed NOx), as a heterogeneous catalyst, has exhibited good catalytic performance in alcohol oxidation. A broad range of alcohols were oxidized to their corresponding aldehydes or ketones with more than 99% selectivity and 99% conversion rate by such a catalyst system at room temperature in air. NOx not only acted as an electron bridge between O2 and 4-OH-TEMPO but also were conducive to the formation of the aldehydes as active component. A possible mechanism for oxidation of alcohols promoted by silica-supported 4-OH-TEMPO/NOx was supposed.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]
GRAPHICAL ABSTRACT
![](/cms/asset/52044e67-a211-4699-ad97-9e86e4976fbc/lsyc_a_827207_o_uf0001.jpg)
ACKNOWLEDGMENT
This work is partially supported by the Program for Changjiang Scholars and Innovative Research Team in University (IRT0711).
Notes
a Quality percentage.
b Silica-supported 4-OH-TEMPO/NOx had been used five times.
a Diameters of the pores are between 1.7000 and 300.0000 nm.
b BJH adsorption average pore diameter (4 V/A).
c Silica supported 4-OH-TEMPO has been used once.
d Catalyst has been used five times.
a Substrate (1 mmol), silica-supported 4-OH-TEMPO/NOx (0.5 g), CH2Cl2 (6 mL), room temperature, and ambient pressure. Conversion and selectivity determined by GC.
b No product was detected.