Copper-catalyzed asymmetric propargylic substitution with salicylaldehyde-derived imine esters. Issue 61 (11th July 2022) - Wang, Ruo-Qing
Abstract : Cu-catalyzed asymmetric propargylic substitution with salicylaldehyde-derived imine esters was successfully realized, generating a series of chiral amino acid derivatives containing propargylic groups with excellent results. Abstract : Copper-catalyzed asymmetric propargylic substitution with salicylaldehyde-derived imine esters and propargylic carbonates has been successfully realized, generating a wide range of chiral amino acid derivatives containing propargylic groups with excellent results (up to 95% yield and 94% ee). The ortho -hydroxy group of the salicylaldehyde-derived imine esters is crucial to increase the reactivity and stabilize the azomethine ylide, which may be due to the formation of an intramolecular hydrogen bond between the hydroxyl group and the imine group. A series of synthetic transformations were carried out to access other important chiral compounds, which displayed the synthetic versatility.