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.     

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.     

A simple method for the oxidation of primary alcohols with o-iodoxybenzoic acid (IBX) in the presence of acetic acid

A simple method for the oxidation of primary alcohols to aldehydes using o-iodoxybenzoic acid (IBX) with the addition of stoichiometric acetic acid has been developed. Addition of acetic acid significantly accelerated the reaction rate. Under these conditions, primary aliphatic, benzylic, and allylic alcohols are smoothly converted to aldehydes in high yields (90-97%).     

A simple protocol for the synthesis of 2-arylbenzoxazoles by oxidation with o-iodoxybenzoic acid (IBX) and its application in the synthesis of arylbenzoxazole-containing amino acids

A simple protocol for the preparation of 2-arylbenzoxazoles has been developed based on the oxidation of phenolic Schiff bases with o-iodoxybenzoic acid (IBX), wherein the oxidant can be recycled. The robustness of this new protocol has been demonstrated in the synthesis of arylbenzoxazole-containing amino acids.     

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.     

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.     

Cr(III) or Ce(IV) impregnated perfluorinated resin-sulfonic acid catalyst for the oxidation of alcohols

Several polymer supported catalysts are prepared by treatment of Nafion® 511 (abbreviated as NAFK below) with metal salts and found to be effective in promoting the dehydrogenative oxidation of alcohols with ^tBuOOH.     

Controllable and efficient oxidation of thioether by 2-iodoxybenzoic acid (IBX) in water: semisynthesis of sophocarpine

A metal-free, environment friendly, easy-to-operate, and efficient method for the semisynthesis of sophocarpine from matrine has been developed in an overall yield of 91%. The route features a controllable and efficient oxidation of thioether to sulfoxide by 2-iodoxybenzoic acid (IBX) in water.     

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.     

An efficient and sustainable protocol for oxidation of alcohols to carbonyl compounds

A simple and extremely efficient protocol is developed for oxidation of alcohols to carbonyl compounds at room temperature by using green solvent lactic acid and green oxidant H₂O₂. This protocol provides high conversion under catalyst free conditions. The easy work up procedure allows high selectivity and good to excellent yields of carbonyl compounds with purity. We have performed wide range of substrates in present study with primary focus on reusability of lactic acid.     

Green and chemoselective oxidation of alcohols with hydrogen peroxide: A comparative study on Co(II) and Co(III) activity toward oxidation of alcohols

Two new cobalt (II) and cobalt (III) complexes of a terpyridine based ligand, (4′-(2-thienyl)-2,2′;6′,2″-terpyridine (L)), were synthesized. Each complex has two units of the tridentate ligand. The complexes were fully characterized by spectroscopic methods as well as CHN analysis. Moreover, their solid state structures were determined by single crystal X-ray diffraction. The cobaltous complex has the formula [Co(L)₂](NO₃)₂·2CH₃OH·H₂O (1), whereas the cobaltic complex shows the formula [Co(L)₂](NO₃)₃·2CH₃OH (2). Both complexes were tested as homogenous catalysts for the oxidation of a variety of aliphatic and aromatic alcohols utilizing aqueous hydrogen peroxide in water media. The Co(II) complex showed more activity in comparison with its isostructural Co(III) species. The results show that the aromatic alcohols were oxidized with higher conversions and selectivity compared to the aliphatic substrates, possibly due to their conjugation systems which thermodynamically stabilized the carbonyl products.     

A green oxidation protocol for the conversion of secondary alcohols into ketones using heterogeneous nanocrystalline titanium (IV) oxide in polyethylene glycol

Abstract

The oxidation of secondary alcohols into corresponding ketones has been described using heterogeneous nanocrystalline TiO₂ as catalyst at a moderate temperature with quantitative yields. Use of H₂O₂ instead of O₂ (g) is the main feature of our methodology since maintenance of P_O2 (g) at elevated temperature is not easy. Besides, this catalyst could be recovered and reused for further reactions with consistent activity. Hence, our present protocol is economical and throughout clean consisting of green reagent, solvent, and catalyst.     

Modified o-methyl-substituted IBX: room temperature oxidation of alcohols and sulfides in common organic solvents

o-Methyl-substituted Me-IBX is the first modified analog of IBX that oxidizes alcohols in common organic solvents at room temperature, due to a composite of two factors, that is, low solubility and hypervalent twisting-promoted rate enhancement. Furthermore, the reagent is efficient for selective oxidation of sulfides to sulfoxides, a transformation that otherwise occurs only sluggishly with standard IBX. The facile synthetic accessibility and its mild as well as non-hazardous nature render Me-IBX a stable equivalent of Dess-Martin periodinane reagent in organic oxidations.     

A mild and efficient oxidation of alcohols to aldehydes and ketones with periodic acid catalyzed by chromium(III) acetylacetonate

Chromium(III) acetylacetonate was found to be an efficient catalyst (10 mol%) for the oxidation of alcohols to aldehydes and ketones with periodic acid (1.5 equiv.) in acetonitrile at room temperature.     

A simple and highly practical oxidation of primary alcohols to acids mediated by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)

Primary alcohols were quantitatively oxidized in one-pot to acids via 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidation. The reported method is simple and suitable for large scale synthesis.     

Oxidative rearrangement of cyclic tertiary allylic alcohols with IBX in DMSO

A practical and environmentally friendly method for oxidative rearrangement of five- and six-membered cyclic tertiary allylic alcohols to beta-disubstituted alpha,beta-unsaturated ketones by the IBX/DMSO reagent system is described. Several conventional protecting groups (e.g., Ac, MOM, and TBDPS) are compatible under the reaction conditions prescribed.     

A simple procedure for the esterification of alcohols with sodium carboxylate salts using 1-tosylimidazole (TsIm)

An efficient and selective method for esterification of alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of RCO₂Na (R: alkyl and aryl), TsIm, and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF to afford the corresponding esters in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

A remarkably simple protocol for the N-formylation of amino acid esters and primary amines

A simple, convenient, and wide scope protocol for the N-formylation of amino acid esters and primary amines has been developed utilizing only imidazole in warm DMF.     

Rapid reduction of alkyl tosylates with lithium triethylborohydride. A convenient and advantageous procedure for the deoxygenation of simple and hindered alcohols. Comparison of various hydride reagents

Lithium triethylborohydride (super-hydride) in tetrahydrofuran reduces the p-toluenesulfonates of primary and secondary alcohols to the corresponding alkanes in excellent yields. The reaction is general and applicable even to tosylates derived from cycloalkanols, hindered alcohols, and polyhydroxy derivatives. Examination of the scope of the reaction and comparison with the results realized with other hydridic reducing agents reveals the advantages of this new procedure.