Cu-Catalyzed Regio- and Diastereoselective Propargylic Substitution of N-Hydroxyphthalimide Esters: Access to Propargyl-Containing N,O-Acetal Derivatives.

Herein, we report the copper-catalyzed propargylic substitution reaction between N-acyl phenylglycine N-hydroxyphthalimide (NHP) esters as a direct C-2-position nucleophile to racemic propargylic carbonates. The reaction affords multifunctionalized N,O-acetal products bearing a terminal-alkyne unit in high yields (up to 97%) with excellent diastereoselectivities (up to >19:1 dr) under mild reaction conditions. Moreover, the products serve as versatile intermediates that can be readily transformed into structurally diverse derivatives, offering significant potential for the exploitation of pharmaceutically relevant molecules.