Aerobic oxidative conversion of alcohols to nitriles using a heterogeneous copper catalyst

One-pot synthesis of nitriles from alcohols using a reusable MOF-derived Cu@C catalyst

This technology is a one-pot synthesis method that converts aromatic primary alcohols into aldehydes via oxidation using a carbon-supported copper catalyst (Cu@C) derived from the pyrolysis of HKUST-1 metal-organic frameworks, along with TEMPO and 1-methylimidazole in an oxygen atmosphere, followed by the addition of an ammonia source to the same vessel for continuous conversion into nitriles.

Benzonitrile synthesis has traditionally relied on cross-coupling aryl halides with toxic metal cyanides, and methods using less toxic cyanide sources have faced issues with significant halide byproducts and waste. While aerobic oxidative conversion using ammonia is eco-friendly, there has been a lack of heterogeneous catalysts that remain stable in the presence of ammonia and can be reused.

This technology produces nitriles in a single reactor without isolating the aldehyde intermediate and uses oxygen as an oxidant, generating almost no byproducts other than water. The Cu@C catalyst can be recovered by centrifugation and reused up to three times without calcination while maintaining yield, reducing catalyst costs. It can be applied to the production of pharmaceutical and agrochemical intermediates and fine chemical raw materials, allowing for the high-yield production of various aromatic nitriles without the need for cyanide handling facilities.

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Key Features:

• Step 1: Aerobic oxidation of aromatic primary alcohols to aromatic aldehydes under oxygen supply conditions
• Step 2: A one-pot continuous process of adding an ammonia source to the same reaction vessel where the aromatic aldehyde was generated to convert it into a nitrile
• Performing both steps in a solvent under oxygen supply using a heterogeneous copper catalyst, TEMPO, and the organic base 1-methylimidazole
• Cu@C catalyst obtained by pyrolyzing HKUST-1 to support copper on a carbon scaffold, which is recovered by centrifugation and reused up to three times with the same yield without calcination

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

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