Mineral-like catalyst based on copper phyllosilicate modified with cerium oxide for one-pot hydroamination of 5-hydroxymethylfurfural with nitro compounds

Introduction into the practice of organic synthesis of new approaches based on the use of bioavailable molecules is a new milestone in the development of organic chemistry. 5-Hydroxymethylfurfural (5-HMF), for example, is a natural synthon for the production of furan-containing chemicals with a wide range of applications from new types of polymers to drug development. Reductive amination of 5-HMF makes it possible to obtain a number of hard-to-reach secondary amines that have unique biological activity and are currently actively studied or even used in medicine. The classical reductive amination of 5-HMF is carried out in two stages with the preparation of an intermediate imine and its further reduction to the target N-furfurylamine using stoichiometric reducing agents, which inevitably leads to a large amount of waste and the need for thorough purification of the target product. Heterogeneous hydroamination is a better alternative, but the production of target N-furfurylamines with high selectivity is limited by the use of expensive noble metal catalysts. In addition, amines are not readily available substrates, and their cost can be comparable to or even higher than that of noble metals.

Scientists from the Laboratory of Development and Study of Polyfunctional Catalysts of the ZIOC proposed the idea of using a mineral-like copper catalyst, easily obtained synthetically, for hydroamination of 5-hydroxymethylfurfural not with amines, but with more accessible nitro compounds, in a "one-pot" mode. Researchers obtained a nanosized artificial mineral copper phyllosilicate doped with cerium oxide based on industrial silica gel. The addition of cerium oxide makes the catalyst more active and stable and it can be reused after the calcination step without loss of activity. The resulting mineral-like catalyst exhibits high activity and selectivity in the reaction of hydroamination of 5-HMF with nitroarenes, which made it possible to obtain a number of hard-to-reach N-furfurylamines in 40–85% yields under relatively mild conditions (150°C, H2 10 atm) in the “one-pot” mode.

A thorough study of the physicochemical characteristics of the resulting catalyst made it possible to propose a possible scheme for the hydroamination of 5-hydroxymethylfurfural with nitroaromatic compounds and the evolution of the catalyst structure during the reaction.

The article was published as part of the special issue "Catalysis talents" of the international journal ChemCatChem.

Source:

Elena Redina, Natalia Arkhipova, Gennady Kapustin, Olga Kirichenko, Igor Mishin, Leonid Kustov Ceria-modified copper phyllosilicate catalyst for one-pot hydroamination of 5-HMF with nitro-compounds // ChemCatChem 2023, e202300294. DOI: 10.1002/cctc.202300294.