Organothianthrenium salts are a class of compounds containing a positive charged sulfur atom and a neutral sulfur atom. Over the past years, organothianthrenium salts have been emerging as attractive precursors...

The synthesis of amides is a long-term theme in chemistry and related areas. The use of readily available and cost-effective precursors for straightforward amide synthesis with atom economy under mild conditions is attractive yet challenging. Herein, we report the direct synthesis of amides from aldehydes and imines in a 100% atom-economical manner. The redox-neutral C–N bond-forming process was enabled by the dual catalysis of visible light and an N-heterocyclic carbene (NHC) at room temperature. This protocol features the unprecedented umpolung of imines to generate N-centered radicals. Mechanistic investigations reveal this reaction undergoes nontrivial radical–radical coupling between an N-centered radical and a C-centered radical to forge a C–N bond. This operationally simple protocol tolerates a wide range of functional groups, providing rapid access to amides from aromatic or aliphatic aldehydes with imines without producing any byproduct.

Selective functionalization of allylic C-H bonds into other chemical bonds are among the most straightforward and attractive, yet challenging transformations. Herein, a transition-metal-free protocol for direct allylic C-H nitrogenation, oxygenation,...

Direct functionalizations of two distinct inert C−H bonds represent the most ideal ways to construct C−C bonds. Herein, we report an intermolecular vinylation of aldehydes using alkenes as the vinylating reagents through sequential two-fold C−H functionalizations. The merging of visible light and N-heterocyclic carbene catalysis allows for the coupling of alkenes with aldehydes through a dual catalysis relay enabled cross-dehydrogenative coupling mechanism. The use of diphenoquinone is essential for the success of this reaction, which plays an intriguing two-fold role in the reaction, as an electron acceptor as well as a radical reservoir for the radical coupling enabling the C−C forming process.

All‐carbon quaternary centers are prevalent in bioactive small molecules. However, their efficient construction remains a formidable synthetic challenge. Here we report cyclic iodine(III) reagents enable the synthesis of cyclopentanones, cyclohexanones, and dihydrofuranones bearing α‐quaternary centers by photoredox catalysis. The reaction proceeds by the formation of the novel cyclic iodine(III) reagent‐allylic alcohol complex, which enables the first alkyl boronate addition and semi‐pinacol rearrangement of allylic alcohols with dual alcohol and olefin activation. The reaction is suitable for gram scale synthesis and is transformable to alcohols, olefins, oximes, and lactones with an α‐quaternary center in one step.