2-Methyl-2-propanol as solvent for o-iodoxybenzoic acid (IBX) oxidation of 1? alcohols to aldehydes

2-Methyl-2-propanol has been demonstrated to be an effective solvent for IBX oxidation of 1? alcohols to the corresponding aldehydes. IBX has a measurable, but low, solubility in 2-methyl-2-propanol and thus partially avoids the drawbacks inherent in the solubility problems associated with IBX without resorting to less desirable solvents. This may be particularly useful where solubility of the alcohol is also at issue.     

Selective and efficient oxidative modifications of flavonoids with 2-iodoxybenzoic acid (IBX)

2-Iodoxybenzoic acid (IBX), a mild and efficient hypervalent iodine oxidant, has been utilised in different reaction conditions to perform several efficient oxidative modifications of flavonoids. Fine-tuning of the reaction conditions allowed remarkably selective modifications of these compounds. At room temperature, IBX proved to be an excellent reagent for a highly regioselective aromatic hydroxylation of monohydroxylated flavanones and flavones, generating the corresponding catecholic derivatives showing high antioxidant activity. At 90 °C, IBX efficiently dehydrogenated a large panel of methoxylated flavanones to their corresponding flavones exhibiting anticancer activity. IBX polystyrene has also been utilised to increase the recovery of highly polar compounds. Following the first oxidation, the reagent was recovered and reused in several runs without loss of efficiency and selectivity. The first example of an application of IBX polystyrene in a dehydrogenation reaction has been described.     

Mild oxidation of alcohols with O-iodoxybenzoic acid (IBX) in ionic liquid 1-butyl-3-methyl-imidazolium chloride and water

[reaction: see text] A mild, efficient, and eco-friendly procedure for the oxidation of alcohols with IBX in ionic liquid [bmim]Cl and water has been developed. Simply stirring of a solution of the alcohol and IBX in [bmim]Cl/water at room temperature followed by extraction with ether or ethyl acetate and removal of the solvent gives excellent yields of the corresponding carbonyl compounds. Recycling and reuse of the oxidant and ionic liquid have also been reported.     

Studies on oxidations with IBX: oxidation of alcohols and aldehydes under solvent-free conditions

A variety of allylic and benzylic alcohols are oxidized to their respective carbonyl compounds with IBX under solvent-free conditions at ca. 60-70 °C. It has also been found that some of the aromatic aldehydes also undergo oxidation when heated with IBX at 90 °C under solvent-free conditions; notably, this transformation does not occur under the otherwise identical but heterogeneous conditions.     

In situ generation of o-iodoxybenzoic acid (IBX) and the catalytic use of it in oxidation reactions in the presence of Oxone as a co-oxidant

[structure: see text] Catalytic use of o-iodoxybenzoic acid (IBX) in the presence of Oxone as a co-oxidant is demonstrated for the oxidation of primary and secondary alcohols in user- and eco-friendly solvent mixtures. Also demonstrated is the in situ (re)oxidation of 2-iodosobenzoic acid (IBA) and even commercially available 2-iodobenzoic acid (2IBAcid) by Oxone to IBX allowing one to use these less hazardous reagents, in place of potentially explosive IBX, as catalytic oxidants.     

Pyridinium o-iodoxybenzoate as a Safe form of a Famous Oxidant

The stable pyridinium salt of o-iodoxybenzoic acid (PIBX) that is easy to obtain can serve as a convenient substitute of IBX as an oxidant. PIBX is safer, has neutral properties behaves as an equivalent to IBX in the oxidation of alcohols to ketones or aldehydes in polar solvents (DMF, DMSO), and provides higher oxidation rate in THF due to better solubility.     

IBX Oxidation of Benzenedimethanols in the Presence of Cucurbit[8]uril

The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o‐iodoxybenzoic acid (IBX) in aqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronic and geometric structure of substrate. In the cases of o‐benzenedimethanol ( 1a ) and m‐benzenedimethanol ( 1b ), the IBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation of the catalytic activity of Q[8] when p‐benzenedimethanol ( 1c ) is subjected to the IBX oxidation. The addition amount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidation much more. The investigation of host‐guest interactions by isothermal titration calorimetry implies the supramolecular catalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril.     

Functional group transformation from amines to aldehydes via IBX oxidation

IBX oxidation of secondary aryl amines has been applied towards their functional group transformation to aldehydes using a facile post-process with satisfactory yields. The oxidation of N-benzylmethylamine was used as a model substrate and suggested that the ratio of IBX oxidant to amine should be 2:1. Subsequently, several aryl amines were subjected to these standard conditions, which revealed that the oxidative activity depends on the electronic and steric structures of the substituent groups in the substrates. The oxidative selectivity to secondary amines was also discovered.     

Direct oxidative conversion of aldehydes to nitriles using IBX in aqueous ammonia

A mild, simple, chemoselective and high yielding procedure for the direct oxidative conversion of aldehydes to nitriles has been developed using IBX in aqueous ammonia.     

Nitromethane with IBX/TBAF as a nitrosating agent: synthesis of nitrosamines from secondary or tertiary amines under mild conditions

Aliphatic or aromatic N,N-disubstituted nitrosamine was generated in fair to excellent yield from the reaction of a secondary or tertiary amine with o-iodoxybenzoic acid (IBX) or o-iodosylbenzoic acid (IBA)/R(4)NX (X = halide) and nitromethane. The product yield was strongly influenced by both the halide of R(4)NX and iodanes. IBX gave a higher yield than IBA, while the halides follow F(-) > Cl(-) > Br(-) ～ I(-). Nitrous acid formed in situ from nitromethane and IBX (or IBA)/halides is likely responsible for the observed reaction.     

2-碘酰基苯甲酸(2-Iodoxybenzoic acid, IBX)在有机合成中的应用

综述了近年来2-碘酰基苯甲酸(2-iodoxybenzoic acid, IBX)在有机合成中的应用, 重点评述了IBX对醇类、含氮有机物、含硫有机物、连接在芳环上的碳原子的氧化反应, 探讨了IBX在α,β-不饱和羰基化合物和内酯合成中的应用, 这些反应具有反应条件温和、产率高、选择性好等优点. 简单介绍了IBX的一些新衍生物的合成及应用.     

Facile synthesis of isatins by direct oxidation of indoles and 3-iodoindoles using NIS/IBX

A facile one-pot access to a broad range of isatins by direct oxidation of indoles using NIS/IBX reagent in DMSO at 25?°C in very good isolated yields is reported. It is shown by mechanistic investigations that a number of substituted indoles react rapidly with NIS in DMSO to produce intermediary 3-iodoindoles, which undergo oxidation subsequently to isatins with IBX.     

An effective and catalytic oxidation using recyclable fluorous IBX

Oxidation of alcohols in the presence of a catalytic amount of fluorous IBX and Oxone as a co-oxidant resulted in the corresponding carbonyl compounds in good to high yields. The fluorous IBX is readily recovered as insoluble fluorous IBA from the reaction mixture by simple filtration, and can be reused without significant loss of the catalytic activity.     

IBX,an Excellent Reagent for Oxidation of 2-Furyl Carbinols: A New and General Method for Preparation of Furyl Ketones

An excellent method for the oxidation of various 2-furyl carbinols with o-iodoxybenzoic acid (IBX) has been described. This method provides a simple and efficient route to a variety of 2-furylketones which are not readily accessible otherwise.     

A facile route to a polymer-supported IBX reagent

A three-step preparation of a polymer-supported IBX reagent from poly(p-methylstyrene) is reported. This reagent has been used successfully for the efficient oxidation of a series of alcohols to the corresponding aldehydes.     

A simple and advantageous protocol for the oxidation of alcohols with O-iodoxybenzoic acid (IBX)

[reaction: see text] An efficient, user-friendly procedure for the oxidation of alcohols using IBX is described. Simply heating a solution of the alcohol in the presence of suspended IBX followed by filtration and removal of the solvent gives excellent yields of the corresponding carbonyl compounds. We illustrate this procedure with a panel of primary and secondary alcohol substrates and note that it allows recycling and reuse of the oxidant.     

Highly selective oxidative cleavage of beta-cyclodextrin-epoxide/aziridine complexes with IBX in water

Water, an environmentally friendly reaction medium, has been utilized for the reaction of IBX with various epoxides 1 and aziridines 2 as their beta-cyclodextrin complexes to afford for the first time alpha-hydroxyketones 3 and alpha-aminoketones 4, respectively.     

Enhancing 2-iodoxybenzoic acid reactivity by exploiting a hypervalent twist

A rearrangement of hypervalent bonds, or twisting, proves to be the rate-determining step in the 2-iodoxybenzoic acid (IBX) oxidation of alcohols. From this insight, derived from density functional theory calculations, we explain why IBX oxidizes large alcohols faster than small ones and propose a modification to the reagent predicted to make it more active.     

Mild oxidation of alcohols with o-iodoxybenzoic acid (IBX) in water/acetone mixture in the presence of beta-cyclodextrin

A mild and efficient oxidation of alcohols with o-iodoxybenzoic acid (IBX) catalyzed by beta-cyclodextrin in a water/acetone mixture (86:14) has been developed. A series of alcohols were oxidized at room temperature in excellent yields.     

The oxidation of alcohols with O-iodoxybenzoic acid (IBX) in aqueous nanomicelles at room temperature

GMPGS-2000, a nonionic amphiphile composed of Guerbet alcohol (2-octyldodecan-1-ol), MPEG-2000 and succinic acid, has been prepared as an effective nanomicelle forming species for the oxidation of alcohols with 2-iodoxybenzoic acid (IBX) in water at room temperature.