One-pot amination of aldehydes and ketones over heterogeneous catalysts for production of secondary amines

Abstract

This review summarizes the recent studies on the synthesis of secondary amines by one-pot amination of aldehydes and ketones over heterogeneous catalysts. Amines are widely applied as the key intermediates in chemical industry for the synthesis of various commodities such as agrochemicals, drugs, detergents, lubricants, food-additives and polymers. Direct catalytic reductive amination of carbonyl compounds was considered which generally includes two steps: (i) formation of imines by interactions of aldehydes or ketones with amines, and (ii) subsequent hydrogenation of imines. Synthesis of secondary amines from carbonyl compounds and amines generated in situ under reaction conditions from their progenitors, e.g., respectively, alcohols or nitro-compounds, is also discussed in detail. Recent progress in application of hydrogen sources alternative to gaseous H 2 , such as formic acid, NaBH 4 , CO and water, favored development of metal-free catalysts including solid acid catalysts. The review addresses the scope of the amination reaction with aldehydes/ketones and nitro/amine compounds of different structure, the effect of the solvent, reaction conditions and catalyst properties. In addition, catalyst regeneration and reuse, kinetic regularities and kinetic modeling with an emphasis on the continuous mode of one-pot amination have been systematically summarized and discussed. It is suggested that the future work should focus on revealing the role of the catalytically active sites addressing their acid-base properties and the correlation between catalyst properties and the reaction performance, elucidating kinetic parameters and designing feasible reactor system for further industrial implementation.

Surface Chemistry of Ketones and Diketones on Lewis Acidic γ-Al2O3 Probed by Infrared Spectroscopy

“…Ketones are an important class of organic reactants that are essential to the chemical industry. They serve as important precursors for the manufacturing of synthetic polymers, 1,2 enantiopure alcohols, 3 imines/amines, 4 and more. Diketones have also been utilized to synthesize specific compounds with high regio, diastereo, and enantioselectivity.…”

“…Ketones are an important class of organic reactants that are essential to the chemical industry. They serve as important precursors for the manufacturing of synthetic polymers, , enantiopure alcohols, imines/amines, and more. Diketones have also been utilized to synthesize specific compounds with high regio, diastereo, and enantioselectivity. , While ketones and diketones may be acquired through a variety of sources and synthesis processes, it is likely that heterogeneous acid–base catalysts, typically metal oxides, are involved in some stage of their production or conversion.…”

Surface modification of metallic catalysts for the design of selective processes

“…Due to the high density of active sites, stability and recyclability, metal nanoparticles are widely used in industrial catalytic processes such as hydrogenation, oxidation, amination, cascade reactions, and so on [1][2][3][4][5][6] . However, one of the main challenges in metal catalysis is insufficient selectivity to target products, which requires additional energy consumption for separation and recycling of by-products.…”

Reductive N-Alkylation of Amines with Ketones Using Heterogeneous Polysilane–Palladium Catalysts under Continuous-Flow Conditions

“…7,8 Among the catalysts employed, heterogeneous catalysts are attractive due to their ease of separation and reusability. 9 The involvement of ketones in reductive N-alkylation is particularly attractive for creating synthetic routes to complex amine structures like α-branched alkyl amines. However, earlier research mainly focused on reactions with aldehydes.…”