Oxidative transformation of alcohols and organic halides in aqueous solution

Abstract

Using water as the only solvent for the oxidation of alcohols and organic halides, a complete solventless process for the preparation of water immiscible aldehydes has been developed.

4-Dimethylaminopyridine-Catalyzed Metal-Free Aerobic Oxidation of Aryl α-Halo Esters to Aryl α-Keto Esters

“…They require sodium 2-propanenitronate, DMSO, trimethylamine N -oxide, pyridine/4-nitrosodimethylaniline, and hexamine/H 2 O as key reagents for oxidizing organic halide. Other methods using various oxidants such as pyridine N -oxide, Hg 2 (NO 3 ) 2 , K 2 CrO 4 , MnO 2 , NaIO 4 /DMF, and quinolinium chlorochromate have also been reported. As one of the efforts to develop more effective and sustainable reactions, the catalytic oxidations of halomethyls to aldehydes or ketones have been developed using oxidant–catalyst combinations including H 5 IO 6 –ionic liquid [C 12 mim]­[FeCl 4 ], O 2 –mesoporous silica, H 2 O 2 –V 2 O 5 /Aliquat 336, and H 2 O 2 –molybdate-based magnetic nanoparticles …”

A green procedure for direct oxidation of organic halides to aldehydes and ketones catalyzed by a molybdate-based catalyst

“…Various reagents have been developed as oxygen donors for this transformation over the decades. Some of these reagents are Mg-Al hydrotalcite, 8 pyridine N-oxide, 9 V 2 O 5 , 10 NaIO 4 -DMF, 11 quinolinium chlorochromate, 12 H 5 IO 6 in [C 12 mim][FeCl 4 ], 13 and amine oxide. [14][15][16] However, some of these methods suffer from drawbacks such as long reaction time, high temperature, low yields, being harmful to the environment and difficult separation of the product from the reaction mixture.…”

NaBrO3/guanidinium-based sulfonic acid: as a transition metal- and strong inorganic acid-free oxidation system for alcohols and alkyl arenes

“…Recently, a large number of organic and inorganic oxidants have been studied in this area. [7][8][9][10][11] Sodium bromate is an important oxy-halo reagent which has been employed as a useful oxidizing agent for this purpose because of its multi-electron transfer ability. [12][13][14][15] In spite of the fact that sodium bromate is thermodynamically a strong oxidant, according to the literature, the bromate anion itself cannot oxidize organic compounds.…”