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The peroxynitrite anion (ONOO−) is closely associated with many diseases and the creation of ONOO− donors is an essential means of understanding its pathophysiological functions. However, it is challenging to develop ONOO− donors due to the difficulties in simultaneously producing highly reactive and short‐lived nitric oxide (NO) and superoxide anion (O2⋅−). Here, we report a novel strategy for constructing ONOO− donors by combining near‐infrared (NIR)‐mediated type I photosensitization and photoredox catalysis. The key design using a Nile blue analogue that can serve as both a type I photosensitizer and a metal‐free photocatalyst. Intriguingly, the formation of O2⋅− via type I photosensitization avoids oxygen interference and instead activates nitrobenzofurazan‐based NO donors via oxygen‐tolerant NIR photoredox catalysis. The simultaneous release of O2⋅− and NO leads to ONOO− release, showing both antibacterial and antibiofilm activities. [ABSTRACT FROM AUTHOR]

Herein, we report a reductive cross‐coupling reaction of α‐oxy halides, simply generated from aldehydes, with a series of C(sp2)‐ and C(sp)‐electrophiles. A wide range of aryl and heteroatom aryl halides, vinyl bromides, alkynyl bromides, and acyl chlorides react with unhindered and hindered aldehyde‐derived α‐oxy halides by providing protected alcohols as well as α‐hydroxy ketones. Noteworthy, the reductive couplings are achieved not only through thermal catalysis with the use of metal reductants but also by photocatalysis, electrochemistry, and mechanochemistry. The unrestricted interchange of the four strategies indicates their underlying mechanistic similarities. The generation of NiI intermediate is proposed to be the key point for ketyl radical formation via a single‐electron transfer (SET) event, which was rationalized by an array of control experiments and density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

Alkynes are an important class of organic molecules due to their utility as versatile building blocks in synthesis. Although efforts have been devoted to the difunctionalization of alkynes, general and practical strategies for the direct hydroalkylation and alkylarylation of terminal alkynes under mild reaction conditions are less explored. Herein, we report a photoredox/nickel dual‐catalyzed anti‐Markovnikov‐type hydroalkylation of terminal alkynes as well as a one‐pot arylalkylation of alkynes with alkyl carboxylic acids and aryl bromides via a three‐component cross‐coupling. The results indicate that the transformations proceed via a new mechanism involving a single‐electron transfer with subsequent energy‐transfer activation pathways. Moreover, steady‐state and time‐resolved fluorescence‐spectroscopy measurements, density functional theory (DFT) calculations, and wavefunction analysis have been performed to give an insight into the catalytic cycle. [ABSTRACT FROM AUTHOR]

Chemical transformations based on cascade reactions have the potential to simplify the preparation of diverse and architecturally complex molecules dramatically. Herein, we disclose an unprecedented and efficient method for the cross‐coupling of radical precursors, dienes, and electrophilic coupling partners via a photoredox‐ and nickel‐enabled cascade cross‐coupling process. The cascade reaction furnishes a diverse array of saturated carbo‐ and heterocyclic scaffolds, thus providing access to a quick gain in C−C bond saturation. [ABSTRACT FROM AUTHOR]

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