UV Assisted High‐Efficient Synthesis of α‐Ketoamides using Air Promoted by A Non‐Metal Catalyst in Aqueous Solution

Abstract

Presented here is the first example of UV (λ=210 nm) promoted procedure proceeding in aqueous media at room temperature using ambient air as the oxidant for efficient synthesis of an array of α‐ketoamides of all types using a non‐metal catalyst N‐iodosuccinimide with a loading of 20 mol%. With UV, oxygen in the air was efficiently utilized as the green oxidant, some control experiments were carried out and a plausible mechanism was proposed, disclosing that in aqueous solution, the oxidation process was actually triggered by dioxygen radical anion (O2.−), while not molecular oxygen. A variety of secondary amines and primary amines as well as ammonia were employed as the amine moieties, and the desired product primary‐, secondary‐, and tertiary α‐ketoamides were afforded in good to excellent yields of up to 96 %.

Iodine–TBHP mediated efficient synthesis of α-ketoamides from vinyl azides and amines under mild conditions

“…It is worth mentioning that these methods were executed using metal or metal-free catalysts, oxidants, and other reagents under different conditions. In recent years, few synthetic approaches for α-ketoamides have been reported using the customary substates via photo 16 or metal catalysis, 17 oxidation, 18 electrochemical, 19 and direct amidation processes. 20 Because of the bulk contribution to the chemical and biological fields, developing novel methods for the direct synthesis of α-ketoamides is highly desirable.…”

Oxidative Coupling of Diazo and NH4I: A Route to Primary Oxamates and α-Ketoamides

“…Although many such methods have been developed for the synthesis of oxamates, to the best of our knowledge, there have been a few reports regarding the production of primary oxamates. In the case of α-ketoamides, synthetic methods proposed to date have largely focused on the preparation of secondary and tertiary α-ketoamides from alkenes, alkynes, aryl ethanes, α-ketoaldehydes, α-keto acids, aryl methyl ketones, 1-arylethanols, α-hydroxy ketones, and other starting materials . In contrast, there are only a handful of examples concerning the synthesis of primary α-ketoamides.…”

Unveiling the reaction process of the amine in direct amidation of aromatic ketones in H2O

“…[8][9][10] Our previous studies reported the preparation of diverse α-ketoamides under clean and mild conditions from varying substrates including aryl methyl ketones. [11,12] Currently, there are two issues involved with the direct amidation. Firstly, although I 2 is employed as the catalyst, its loading almost reaches up to the stoichiometric ratio.…”

“…In classical amidations with the addition of iodine (I 2 ), the amine is recognized as the reactant, and I 2 is almost presumed to play the catalytic role . Our previous studies reported the preparation of diverse α ‐ketoamides under clean and mild conditions from varying substrates including aryl methyl ketones . Currently, there are two issues involved with the direct amidation.…”

“…[1,2] Various approaches have been proposed in the synthesis of a diverse array of α-ketoamides from different ketones and amines. [3][4][5][6][7][8][9][10][11][12] Recently, the iodine-driven reaction have emerged as a powerful strategy because of the particularly reactive halogen bond-based systems. In this system, specifically, the drive reagents can be successfully incorporated, resulting from the formation of a highly attractive halogen bond between the iodine of drive reagents and the substrates (e. g., halide atoms).…”