36775-17-4Relevant academic research and scientific papers
Self-neutralizing in situ acidic CO2/H2O system for aerobic oxidation of alcohols catalyzed by TEMPO functionalized imidazolium Salt/NaNO2
Miao, Cheng-Xia,He, Liang-Nian,Wang, Jing-Lun,Wu, Fang
, p. 257 - 260 (2010)
(Chemical Equation Presented) A reversible in situ acidic catalytic system comprising recyclable TEMPO functionalized imidazolium salt ([Imim-TEMPO][Cl])/ NaNO2/CO2/H2O was developed for selective transformation of a series of aliphatic, allylic, heterocyclic, and benzylic alcohols to the respective carbonyl compounds. Notably, the system avoids any conventional acid and can eliminate unwanted byproducts, facilitate reaction, ease separation of the catalyst and product, and also provide a safe environment for oxidation involving oxygen gas.
TEMPO and carboxylic acid functionalized imidazolium salts/ sodium nitrite: An efficient, reusable, transition metal-free catalytic system for aerobic oxidation of alcohols
Miao, Cheng-Xia,He, Liang-Nian,Wang, Jin-Quan,Wang, Jing-Lun
experimental part, p. 2209 - 2216 (2009/12/27)
An effective catalytic system comprising a 2,2,6,6-tetramethylpiperidine-1- oxyl (TEMPO) functionalized imidazolium salt ([Imim-TEMPO]+X -), a carboxylic acid substituted imidazolium salt ([ImimCOOH] +X-), and sodium nitrite (NaNO2) was developed for the aerobic oxidation of aliphatic, allylic, heterocyclic and benzylic alcohols to the respective carbonyl compounds with excellent selectivity up to >99%, even at ambient conditions. Notably, the catalyst system could preferentially oxidize a primary alcohol to the aldehyde rather than a secondary alcohol to the ketone. Moreover, the reaction rate is greatly enhanced when a proper amount of water is present. And a high turnover number (TON 5000) is achieved in the present transition metal-free aerobic catalytic system. Additionally, the functionalized imidazolium salts are successfully reused at least four times. This process thus represents a greener pathway for the aerobic oxidation of alcohols into carbonyl compounds by using the present task-specific ionic liquids in place of the toxic and volatile additive, such as hydrogen bromide, bromine, or hydrogen chloride (HBr, Br2 or HCl), which is commonly required for the transition metal-free aerobic oxidation of alcohols.
TEMPO-derived task-specific ionic liquids for oxidation of alcohols
Wu, Xue-E.,Ma, Li,Ding, Meng-Xian,Gao, Lian-Xun
, p. 607 - 610 (2007/10/03)
A novel 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical bearing an ionic liquid-type appendage has been prepared, and its catalytic activity for the selective oxidation of alcohols to the corresponding carbonyl compounds in ionic liquid-aqueous biphasic conditions has been investigated. The ionic liquid-supported TEMPO radical shows catalyst properties similar to those of nonsupported counterpart in terms of activity and selectivity, and can be easily recycled and reused without loss of activity and selectivity.
