Catalytic Oxidation of Alcohols to Corresponding Aldehydes or Ketones with TEMPO-Mediated Iodosobenzene in Water in the Presence of a Surfactant

Abstract

An efficient, facile, and rapid oxidation of alcohols to the corresponding aldehydes or ketones with a stoichiometric amount of iodosobenzene (PhIO) in the presence of catalytic amounts of 2,2,6,6-tetramethyl-1-piperidinyloxyl free radical (TEMPO), KBr, and a surfactant, such as SDS (sodium dodecylsulfate), was reported. The oxidation proceeded in water at room temperature to afford aldehydes or ketones in excellent yields and high selectivity without overoxidation to carboxylic acids. Selective oxidation of primary alcohols in the presence of secondary alcohols was also achieved with the catalytic system of PhIO/TEMPO/KBr/SDS. A possible mechanism for the oxidation was supposed.

Keywords:

• Alcohols
• iodosobenzene
• oxidation
• TEMPO
• water as solvent

ACKNOWLEDGMENT

We are grateful to Nanjing University of Science and Technology for financial support.

Notes

^a Reaction conditions: p-nitrobenzyl alcohol (1 mmol), PhIO (2.2 mmol), TEMPO (0.1 mmol), KBr (0.2 mmol), surfactant (0.2 mmol), water (5 mL) at room temperature for 2 h.

^b Calculated according to Davis law.

^c GC conversion and selectivity.

^d Isolated yield.

^e 0.1 g Tween-80 was added.

^a Reaction conditions: alcohol (1 mmol), PhIO (2.2 mmol), TEMPO (0.1 mmol), KBr (0.2 mmol), surfactant (0.2 mmol), and water(5 mL) at room temperature.

^b GC conversion.

^c Yields of isolated products unless otherwise noted.

^d Yields were determined by GC.

^a The reactions were carried out on a 1:1 mixture of primary and secondary alcohols, on a 1-mmol scale.

^b Isolated yield.