Transition-Metal-Free Oxidative α-C–H Amination of Ketones via a Radical Mechanism: Mild Synthesis of α-Amino Ketones

Abstract

A transition-metal-free direct α-C-H amination of ketones has been developed using commercially available ammonium iodide as the catalyst and sodium percarbonate as the co-oxidant. A wide range of ketone ((hetero)aromatic or nonaromatic ketones) and amine (primary/secondary amines, anilines, or amides) substrates undergo cross-coupling to generate synthetically useful α-amino ketones. The mechanistic studies indicated that a radical pathway might be involved in the reaction process. The utility of the method is highlighted through a concise one-step synthesis of the pharmaceutical agent amfepramone.

Iodine‐Catalyzed Oxidative Amination of Sodium Sulfinates: A Convenient Approach to the Synthesis of Sulfonamides under Mild Conditions

“…Further attempts to drive the reaction to completion by increasing the temperature to 50 or 60 °C were unsuccessful; lower yields of product were obtained and some unidentified byproducts were observed as the temperature increased (Entries 3 and 4). Our results agree with previous reports according to which sodium percarbonate is not an effective oxidant at high temperature 13a,14. Replacing I 2 catalyst with NIS provided product 3a in 55 % yield (Entry 5), whereas use of other iodide sources such as LiI, NaI, KI, and TBAI did not result in product formation (Entries 6–9).…”

Electrochemical Lignin Conversion

“…With halide mediators, propiophenone derivatives can undergo chemical [128] and electrochemical [129] dehydrogenative cross coupling with secondary amines ( Figure 16A). Gao et al further applied this approach on lignin β-O-4 model compounds with amines to produce N,O-ketal mediated by halides including iodide ions (n-Bu 4 NI, KI, NaI) and bromine ion (NaBr).…”

Dual Role of N‐Bromosuccinimide as Oxidant and Succinimide Surrogate in Domino One‐Pot Oxidative Amination of Benzyl Alcohols for the Synthesis of α–Imido Ketones

“…Traditionally, α‐amino ketones can be synthesized from ketone and amine using molecular bromine . In addition to this, recent developments have been made for the synthesis of α‐amino ketones by using both transition‐metal and transition metal‐free conditions . For example, MacMillan et al developed a Cu‐catalyzed α‐amination of ketones .…”