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

摘要

Presented here is the first example of UV (lambda=210 nm) promoted procedure proceeding in aqueous media at room temperature using ambient air as the oxidant for efficient synthesis of an array of alpha-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 (O-2(.-)), 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 alpha-ketoamides were afforded in good to excellent yields of up to 96 %.