Synthesis method for oxoammonium salts and secondary alcohol oxidation using the same

High-Yield Secondary Alcohol to Ketone Oxidation Process Mediated by ABNO Oxoammonium Salt

This technology utilizes the oxoammonium salt ABNO+BF4-, derived from the bicyclic nitroxyl radical ABNO, as a stoichiometric oxidant to oxidize secondary alcohols. It provides optimal reaction conditions using an alkali carbonate as a base in an acetonitrile solvent under a nitrogen atmosphere.

Alcohol oxidation based on nitroxyl radicals like TEMPO often required the use of secondary oxidants such as NaOCl or Br2. While ABNO is known for its excellent catalytic activity, there were previously no reports on the synthesis and properties of ABNO salts or the conditions required to apply them to oxidation reactions.

This technology produces crystalline oxoammonium salt by adding aqueous HBF4, NaOCl, and NaBF4 to ABNO, and efficiently oxidizes secondary alcohols at room temperature using 1.2 equivalents of the salt. The reaction setup is simple as it requires no secondary oxidant. It can be applied to ketone synthesis for pharmaceutical intermediates and fine chemicals, enabling stable oxidation with yields over 70%.

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Key Features:

• A method for oxidizing secondary alcohols mediated by ABNO+BF4- oxoammonium salt
• Reaction conditions performed in an acetonitrile solvent under nitrogen, using an alkali carbonate as a base
• Configuration using at least one selected from potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate as the alkali carbonate
• Conditions using 1.2 equivalents of ABNO+BF4- and 1 equivalent of alkali carbonate at 25°C for 18 hours, achieving a reaction yield of 70% or higher

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This invention was developed with support from the Ministry of Science and ICT for the development of eco-friendly and economical selective aerobic oxidation reactions.

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