Method for preparing primary amines through hydrogen transfer selective nitrile reduction

Abstract

The invention discloses a method for preparing primary amines through hydrogen transfer selective nitrile reduction. The method includes the step of adding low-price copper, iron and other metal saltsor low-price easy-to-obtain iodine elementary substances as additives with a nitrile compound as the raw material and oxazole borane as the hydrogen transfer agent under the mild conditions, therebypromoting the hydrogen transfer reaction and selectively synthesizing a series of corresponding primary amines under different conditions respectively. The high yield and high selectivity are achievedin the reaction. The oxazole borane is obtained through reaction of alkamine and a tetrahydrofuran complex of borane. In addition, the method is mild in reaction condition, easy to operate, free of high-pressure devices, environmentally friendly and high in raw material general applicability, the agents required for the reaction are all low in price and easy to obtain, the reduction product is only primary amines, and selectivity and repeatability are high. Thus, an effective scheme is provided for the industrial production of other high-additional-value compounds of similar structures in future.

Description

Technical field: [0001] The invention belongs to the field of organic synthesis including the synthesis of pharmaceutical intermediates and related chemical technologies, and relates to a method for preparing primary amines by hydrogen transfer selective reduction of nitriles. Background technique: [0002] Primary amines are important raw materials for the synthesis of fine chemicals such as pesticides, medicines, and dyes. The reduction of cyano compounds to amine compounds is one of the commonly used methods for preparing amines in organic synthesis, but the reduction products are usually a mixture of primary and secondary amines. How to selectively reduce cyano groups to prepare primary amines will be a Great challenge. For the catalytic reduction reaction of cyano compounds, predecessors have done a lot of research work. Generally, noble metal catalysts are used, such as iridium, palladium, platinum and ruthenium, etc., which are not only expensive, but also have cert...

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Problems solved by technology

Generally, noble metal catalysts are used, such as iridium, palladium, platinum and ruthenium, etc., which are not only expensive, but also have certain toxicity.

Catalytic hydrogenation usually uses hydrogen as a hydrogen source, and the operation requirements of the reaction are high or dangerous. In addition, some catalysts are more complicated to synthesize [Mukherjee A, Srimani D, Chakraborty S, et al. Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by aCobalt Pincer Complex[J].Journal of the American Chemical Society,2015,137(28):8888-8891.Chakraborty S,Leitus G, Milstein D.Selective hydrogenation of nitrogenes to primary amines catalyzed by a novel iron complex[J].Chemical Communications ,2016,52(9):1812-1815.], so its general application is limited

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