C O M M U N I C A T I O N S
Table 1. Catalytic Aerobic Alcohol Oxidationa
In conclusion, we have successfully developed a highly efficient,
transition-metal-free catalytic process for the aerobic oxidation of
alcohols. The oxidation is carried out under air and promoted by a
mixture of TEMPO/Br2/NaNO2 in catalytic amounts. Under optimal
reaction conditions, a wide range of alcohols can be converted into
corresponding aldehydes or ketones in high selectivity. Moreover,
the newly developed catalyst system can be readily adjusted to suit
various substrates. Mechanistically, the novel use of NO to activate
molecular oxygen plays a crucial role in the TEMPO/Br2/NaNO2
catalytic oxidation cycle. Further studies will focus on the improve-
ment of the process for industrial applications of aerobic alcohol
oxidation.
Acknowledgment. This work was supported by the Young
Faculty Research Fund of DICP.
Supporting Information Available: Detailed experimental pro-
cedures and GC diagrams for all substrates and products. This material
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a Reaction conditions: alcohol (10 mmol), TEMPO (0.1 mmol), Br2 (0.4
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Scheme 1. Overall Catalytic Mechanism
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essential role of HBr played in the catalytic cycle. The reoxidation
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a novel, coherent, and efficient aerobic oxidation system (Scheme
1).
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