BF3·Et2O controlled selective synthesis of α-substituted propargylamides and β-(N-acylamino) ketones: application to carbon and sulphur nucleophiles.

This study presents a metal-free and selective synthesis of α-substituted propargylamides and β-(N-acylamino) ketones utilizing nitriles, aldehydes, and terminal alkynes, mediated by BF3·Et2O. The unique reactivity of BF3·Et2O, a potent Lewis acid, facilitates precise control over product formation. By adjusting the concentration of BF3·Et2O, we can effectively manipulate reaction pathways and selectivity, ensuring the desired products are achieved with enhanced specificity. Notably, this method demonstrates remarkable tolerance to other nucleophiles, such as β-naphthol, indole, arenes and thiol, thereby enabling the synthesis of a diverse array of functionally significant compounds. This approach offers a valuable tool for advancing synthetic methodologies in organic chemistry.