In recent years, the development of light‐mediated methods for synthetic applications has attracted high interest, because such methods constitute alternative approaches for the production of valuable chemical products. We study herein a photochemical protocol for the synthesis of Weinreb amides and morpholine amides from carboxylic acids. Various carboxylic acids were directly coupled to N,O‐dimethylhydroxylamine, upon irradiation with either LED 370 nm or sunlight in the presence of 4‐dimethylaminopyridine and bromotrichloromethane, providing Weinreb amides in moderate to high yields. Similarly, morpholine amides were obtained in satisfactory to high yields under sunlight or LED 370 nm irradiation. Thus, the versatile building blocks Weinreb amides and morpholine amides may be efficiently synthesized directly from carboxylic acids by light‐mediated approaches, without the need of coupling reagents or pre‐activation of carboxylic acids.
The Cover Feature illustrates the photochemical conversion of carboxylic acids to Weinreb and morpholine amides. Sunlight or LED 370 nm irradiation mediates the direct coupling of carboxylic acids to N,O‐dimethylhydroxylamine or morpholine in the presence of 4‐dimethylaminopyridine and bromotrichloromethane, providing the corresponding amides in satisfactory to high yields. More information can be found in the Research Article by C. G. Kokotos, G. Kokotos et al.
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