TEMPO-Based Ionic Liquid with Temperature-Dependent Property and Application for Aerobic Oxidation of Alcohols

Abstract

A novel temperature-dependent ionic liquid based on 2,2,6,6-tetramethylpiperidine-1-oxyl and polyethylene glycol 600 was developed and used in oxidation of alcohols. Various alcohols were oxidized into their corresponding aldehydes or ketones with good yield and selectivity. Owing to the temperature-dependent property of the catalyst, easy recovery was achieved by simple decantation.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

GRAPHICAL ABSTRACT

Notes

^a s, soluble; i, insoluble; and ps, partly soluble.

^a Reaction conditions: benzyl alcohol (1.85 mmol), [Imim-PEG₆₀₀-TEMPO][OMS] (1 mL), cyclohexane (4 mL), CCl₄ (6 mL), NaNO₂ (5% mmol of benzyl acohol), 10% H₂SO₄ (0.1 mL). O₂ was inputted at 0.004 m³/h.

^b According to Ref.^{[ 21 ]}

^a Reaction conditions: benzyl benzyl alcohol (1.85 mmol), cyclohexane (4 mL), CCl₄ 6 mL, 60 °C.

^a Reaction conditions: alcohol (1.85 mmol), [Imim-PEG₆₀₀-TEMPO][OMS] (1 mL), cyclohexane (4 mL), CCl₄ (6 mL), NaNO₂ (5% mmol of benzyl acohol), 10% H₂SO₄ (0.1 mL). O₂ was inputted at 0.004 m³/h, 60 °C.