Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters

Chemistry. 2021 May 20;27(29):7915-7922. doi: 10.1002/chem.202100655. Epub 2021 Apr 22.

Abstract

A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.

Keywords: amides; aromatic aldehydes; esters; green chemistry; hydroxamic acids; photochemistry.