Brønsted Acid-Promoted Intermolecular Dearomative Photocycloaddition of Bicyclic Azaarenes with Olefins under Aerobic Conditions.

Herein, we present a simplified reaction protocol for the dearomatization of bicyclic azaarenes via photochemical cycloaddition with alkenes using an Ir(III) photosensitizer, trifluoroacetic acid (TFA), dichloroethane, and a blue light-emitting diode. An efficient protonation of azaarenes with TFA enhances the reactivity of triplet azaarene toward olefins, enabling the photocycloaddition under aerobic conditions. The protocol applies to a broad range of substrates.

Photocatalytic Incorporation of an Oxime Ether Functional Group at Inert C(sp)-H Bonds via HAT.

Herein, we describe a photocatalytic method for the direct incorporation of an oxime functional group at inert C(sp)-H bonds of ethers, amides, alcohols, amines, and alkanes via HAT with photoexcited eosin Y under mild conditions using air and a blue LED. Many useful functional groups are tolerated in this process, and the reaction is scalable. A series of mechanistic studies were carried out to support the radical pathway proposed for the process.

Photocatalytic Aerobic Coupling of Azaarenes and Alkanes via Nontraditional Cl Generation.

Herein, we demonstrate a nonconventional photocatalytic generation of Cl from a common chlorinated solvent, dichloroethane, under aerobic conditions and its successful utilization toward the cross-dehydrogenative coupling of alkanes and azaarenes via hydrogen atom transfer with Cl. The process is free from chloride salt, toxic oxidant, and UV light. It is applicable to a broad spectrum of substrates.

Heteroarylation of Ethers, Amides, and Alcohols with Light and O.

An efficient protocol for the C-H heteroarylation of ethers, amides, and alcohols using air and light under mild conditions is described. The reaction is applicable to a wide spectrum of functional groups. The generation of C-radicals via photoinduced aerobic oxidation of ethers, amides, and alcohols is the key feature of the process.

Radical C-H Acylation of Nitrogen Heterocycles Induced by an Aerobic Oxidation of Aldehydes.

An aerobic radical approach for the synthesis of unsymmetrical heteroaryl ketones is described herein. The reaction involves cross-dehydrogenative coupling between aldehydes and heteroaromatic bases with molecular oxygen (O ). The key aspect of the method is the generation of reactive acyl radical via homolytic activation of aldehyde C-H bond using O as the sole oxidant.