Copper/TEMPO-Promoted Denitrogenation/Oxidation Reaction for Synthesis of Primary α-Ketoamides Using α-Azido Ketones

Abstract

A copper(II)-promoted denitrogenation/oxidation reaction for the preparation of primary α-ketoamides was developed using α-azido ketones as a substrate and TEMPO as an oxidant. α-Azido ketones were denitrogenated in situ to form an imino ketone intermediate, which underwent a radical addition process and radical migration to form αketoamides. It is worth noting that the imino ketone intermediate is the key to this reaction.

Copper‐Promoted Oxidative Amidation of Imines: A Facile Route to Amides

“…TEMPO was selected as one of the oxidants in that it can also be used as an oxidant to synthesize α-ketoamides as an oxygen source for amidation. [14] The result shows that 3 a was obtained with a yield of 43.2 % (entry 8). Oxone was proved to be the best choice, and there was no 3 a generation without the addition of oxidants (entry 11), indicating direct oxidation by air is negligible.…”

“…Oxone, K 2 S 2 O 8 , TEMPO, CHP and H 2 O 2 ) were added to the reaction mixture (entries 6–10). TEMPO was selected as one of the oxidants in that it can also be used as an oxidant to synthesize α‐ketoamides as an oxygen source for amidation [14] . The result shows that 3 a was obtained with a yield of 43.2 % (entry 8).…”

“…Oxone was proved to be the best choice, and there was no 3 a generation without the addition of oxidants (entry 11), indicating direct oxidation by air is negligible. In addition, different additives exhibited various yields (0-57 %, entries [12][13][14][15][16][17], and the yield was only 3 % (entry 18) in the absence of additives.…”

Preparation of Phenacyl Azides and Their Application Advances in Organic Synthesis

“…最近, 我们课题组 [57] 报道了一种高效制备伯 α-酮 酰胺的方法(Scheme 非常巧合的是, 李金恒 [58] 课题组也报道了一种将 苯乙酰叠氮直接转化为伯 α-酮酰胺的方法(Scheme 18).…”

I2‐Mediated Oxidative Amidation of Aryl Methyl Ketones: Synthesis of Primary α‐Ketoamides Using Ammonium Carbamodithioate as Amine Surrogate

“…[20] Furthermore, Wu's group proposed an I 2 -promoted hydrolysis oxidation of aryl methyl ketones with thiocyanate salt as amino substituents via C � N bond cleavage to synthesize free primary α-ketoamides (Scheme 1c). [21] Because of our continued interest in primary αketoamides, [22] we report herein our research on an efficient I 2mediated oxidative amidation of aryl methyl ketones with ammonium carbamodithioate for the construction of primary αketoamides under an I 2 /DMSO system (Scheme 1d).…”