Ruthenium‐Catalyzed Aerobic Oxidation of Amines

Abstract

Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed.

Efficient Aerobic Oxidation of Organic Molecules by Multistep Electron Transfer

“…[46] Ruthenium-catalyzed oxidation reactions are ac lass of important transformations in organic synthesis. [47] In the past decades,mild dehydrogenations of alcohols to give aldehydes or ketones through the use of low-valent Ru complexes have been reported, which were subsequently extended to the dehydrogenation of amines to imines. [48] TheS tahl group reported aR u-based catalyst system that shows high activity for amine oxidation, including the successful aerobic dehydrogenation of diverse tetrahydroquinolines at room temperature with ambient air (Scheme 15).…”

Methods of Nitriles Synthesis from Amines through Oxidative Dehydrogenation

“…Among the various transition metals (ruthenium, gold, copper, cobalt etc. ), ruthenium has received widespread attention for its ability to dehydrogenate amines . The first ruthenium catalyzed oxidation of amines to nitriles was reported by McWhinnie et al.…”

Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst

“…[1] Since nitriles serve as a versatile synthetic precursor for a variety of functional groups, [2] numerous methodologies for their formation have been developed. [3][4][5][6][7][8][9] The oxidation of primary amines or imines via catalytic dehydrogenation in an oxygen atmosphere is one of the most efficient and environmentally friendly methods to date, particularly for green chemistry applications. [5][6][7][8][9] For nitrile synthesis by catalytic dehydrogenation of primary amines, numerous aerobic conditions using homogeneous and heterogeneous transition metal catalysts including Ru, Fe, and Co catalysts have so far been reported.…”

“…[3][4][5][6][7][8][9] The oxidation of primary amines or imines via catalytic dehydrogenation in an oxygen atmosphere is one of the most efficient and environmentally friendly methods to date, particularly for green chemistry applications. [5][6][7][8][9] For nitrile synthesis by catalytic dehydrogenation of primary amines, numerous aerobic conditions using homogeneous and heterogeneous transition metal catalysts including Ru, Fe, and Co catalysts have so far been reported. [5][6][7] Taking advantage of the high catalytic activity, heterogeneous catalysts [7] are generally advantageous in terms of low catalyst loading, reusability, and scalability.…”

“…[5][6][7][8][9] For nitrile synthesis by catalytic dehydrogenation of primary amines, numerous aerobic conditions using homogeneous and heterogeneous transition metal catalysts including Ru, Fe, and Co catalysts have so far been reported. [5][6][7] Taking advantage of the high catalytic activity, heterogeneous catalysts [7] are generally advantageous in terms of low catalyst loading, reusability, and scalability. However, conditions using highly active catalyst occasionally cause a problem of functional group compatibility due to undesired oxidation or decomposition of sensitive functional groups such as alcohols.…”