Nickel/Photo-Cocatalyzed Three-Component Alkyl-Acylation of Aryl-Activated Alkenes

Nickel/Photoredox Dual-Catalyzed, Regioselective 1,2-Carboacylation of Alkenes via Synergistic Alkyl and Benzoyl Radical Coupling

A regioselective 1,2-carboacylation protocol of alkenes via nickel/photoredox dual catalysis has been successfully developed under mild conditions. A wide range of alkyl bromides, α-oxocarboxylic acids, and styrenes proved to be compatible under the optimized conditions, affording the corresponding 1,2-carboacylation products in up to 91% yields. Mechanistically, the key to the success of this approach is the temporal orchestration of radical generation: nickel-catalyzed halogen atom transfer (XAT) for alkyl bromides and photoredox-driven decarboxylation for α-oxocarboxylic acids.

Decarboxylative Cross-Acyl Coupling of Carboxylic Acids with Aldehydes Enabled by Nickel/Photoredox Catalysis

We present a general method for accessing unsymmetrical alkyl-aryl and alkyl-alkyl ketones via nickel/photoredox-catalyzed decarboxylative cross-acyl coupling reactions between carboxylic acids and aldehydes without the need for an additional preactivation procedure. Specifically, by using the peroxide as both an oxidant and hydrogen atom transfer (HAT) reagent, we achieved the unprecedented combination of oxidative single electron transfer (SET) of carboxylates and HAT of aldehydes, in which the generated alkyl and acyl radicals were chemoselectively coupled by nickel catalysis. This method features a broad substrate scope with good functional group compatibility and offers new access to structurally diverse ketones.

A TBADT-enabled photo-induced radical cyclization pathway: concise access to functionalized oxindoles

Herein, this work describes a mild and general protocol for photo-induced cascade cyclisation of arylalkynamides resulting in diversely functionalized oxindoles. This strategy enables the construction of two C-C bonds through a radical cascade process via a hydrogen atom transfer pathway employing the decatungstate anion ([W10O32]4-) as an efficient HAT photocatalyst. Interestingly, pivaldehyde afforded unexpected Z-indolinones stereospecifically in our strategy.

Photo-/Electrocatalytic Difunctionalization of Alkenes Enabled by C-H Radical Functionalization

The difunctionalization of alkenes represents a powerful tool to incorporate two functional groups into the alkene bones for increasing molecular complexity and has been widely utilizations in chemical synthesis. Upon the catalysis of the green, sustainable, mild photo-/electrochemistry technologies, much attentions have been attracted to the development of new tactics for the transformations of the important alkene and alkane feedstocks driven by C-H radical functionalization. Herein, we summarize recent advances in the photo-/electrocatalytic difunctionalization of alkenes enabled by C-H radical functionalization. We detailedly discuss the substrate scope and the mechanisms of the photo-/electrocatalytic alkene difunctionalization reactions by selecting impressive synthetic examples, which are divided into four sections based on the final terminated step, including oxidative radical-polar crossover coupling, reductive radical-polar crossover coupling, radical-radical coupling, and transition-metal-catalyzed coupling.

Dicarbofunctionalization of Vinylarenes with Pyridine and Aldehydes via Photocatalytic Hydrogen Atom Transfer

We describe a metal-free and mild three-component reaction utilizing vinylarenes, alkyl aldehydes, and 4-cyanopyridine. In this reaction, the scope of vinylarenes and alkyl aldehydes includes over 40 examples, generating a variety of β-pyridinyl ketones. Moreover, potential applications of this method have been demonstrated by the functionalization of pharmaceutical molecules. An acyl radical is proposed to be produced via a polarity-matched hydrogen atom transfer between alkyl aldehydes and a triplet-state diradical from benzophenone.

Recent advances in dual photoredox/nickel catalyzed alkene carbofunctionalised reactions

Alkene carbofunctionalization reactions have great potential for synthesizing complex molecules and constructing complex structures in natural products and medicinal chemistry. Recently, dual photoredox/nickel catalysis has emerged as a novel strategy for alkene carbofunctionalization. Nickel offers numerous advantages over other transition metals, such as cost-effectiveness, abundance, and low toxicity, and moreover, it has many oxidation states. Nickel catalysts exhibit excellent catalytic activity in dual photoredox/transition metal catalysis, facilitating the formation of carbon-carbon or carbon-heteroatom bonds in organic transformations. This review highlights the latest advancements in dual photoredox/nickel-catalyzed alkene carbofunctionalizations and includes the literature published from 2020 to 2024.

Tetrabutylammonium decatungstate (TBADT), a compelling and trailblazing catalyst for visible-light-induced organic photocatalysis

Tetrabutylammonium decatungstate (TBADT) has recently emerged as an intriguing photocatalyst under visible-light or near-visible-light irradiation in a wide range of organic reactions that were previously not conceivable. Given its ability to absorb visible light and excellent effectiveness in activating unactivated chemical bonds, it is a promising addition to traditional photocatalysts. This review covers some of the contemporary developments in visible-light or near-visible-light photocatalysis reactions enabled by the TBADT catalyst to 2023, with the contents organized by reaction type.