Se-catalyzed enantioselective lactamization enabled by a N-fluorosulfonyl group: total synthesis of diaporisoindole A

Abstract

Electrophilic cyclization of unsaturated carboxylic acids is a well-established strategy for the catalytic enantioselective synthesis of lactones. In contrast, analogous catalytic transformations of unsaturated carboxamides to access enantioenriched lactams remain underdeveloped due to the ambident nucleophilicity of carboxamides, favoring nucleophilic attack from their oxygen atom. Herein, we unveil N-(fluorosulfonyl)carboxamides as versatile and reactive substrates that overcome this limitation, as demonstrated by a selenium-catalyzed enantioselective lactamization, facile product derivatization, and application to the total synthesis of diaporisoindole A. To further showcase their synthetic potential, we briefly demonstrate their applicability in racemic iodo- and hydro-lactamizations.