Photoredox‐Catalyzed Decarboxylative Cascade Cyclization of NHPI Esters With Isocyanides: Access to 2‐Alkylbenzothiazoles/2‐Alkylbenzoselenazoles

ABSTRACT A metal‐free photoredox catalysis enabling a decarboxylative radical cascade cyclization for the efficient synthesis of 2‐alkylbenzothiazoles/2‐alkylbenzoselenazoles is described. This protocol utilizes alkyl N ‐hydroxyphthalimide (NHPI) esters and 2‐isocyanaryl thioethers/selenoethers as the substrates, and the transformation proceeds through a photoredox‐catalyzed, radical addition‐triggered cascade cyclization. This method features mild conditions, excellent functional group tolerance, and a broad substrate scope encompassing primary, secondary, and tertiary alkyl radicals, providing a versatile entry to these valuable heterocycles.