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Radical‐involved multicomponent difunctionalization of 1,3‐dienes has recently emerged as a promising strategy for rapid synthesis of valuable allylic compounds in one‐pot operation. However, the expansion of radical scope and enantiocontrol remain two major challenges. Herein, we describe an unprecedented photoinduced copper‐catalyzed highly enantioselective three‐component radical 1,2‐azidooxygenation of 1,3‐dienes with readily available azidobenziodazolone reagent and carboxylic acids. This mild protocol exhibits a broad substrate scope, high functional group tolerance, and exceptional control over chemo‐, regio‐ and enantioselectivity, providing practical access to diverse valuable azidated chiral allylic esters. Mechanistic studies imply that the chiral copper complex is implicated as a bifunctional catalyst in both the photoredox catalyzed azidyl radical generation and enantioselective radical C−O cross‐coupling. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Catalytic four‐component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds. Given the significance of fluorine‐containing groups, this reaction class has been extensively applied to assembly of a variety of perfluoroalkyl carboxylic acid derivatives by transition metal catalysis. Herein, we report a visible‐light‐driven radical relay 1,2‐perfluoroalkylation aminocarbonylation of unactivated alkenes using CO gas as carbonyl source and 4CzIPN as organic photocatalyst. A wide range of alkenes and amines were well tolerated, providing the valuable β‐perfluoroalkylated amides with generally good yields and high chemoselectivity. [ABSTRACT FROM AUTHOR]

Radical single carbonylation reactions with CO constitute a direct and robust strategy toward various carbonyl compounds from readily available chemicals, and have been extensively studied over the past decades. However, realizing highly selective catalytic systems for controlled radical double carbonylation reactions has remained a substantial challenge, particularly for the more advanced multicomponent variants, despite their great potential value. Herein, we report a visible‐light‐driven radical relay five‐component radical double aminocarbonylation reaction of unactivated alkenes using CO under metal‐free conditions. This protocol provides direct access to valuable γ‐trifluoromethyl α‐ketoamides with good yields and high chemoselectivity. Crucial was the identification of distinct dual roles of amine coupling partners, sequentially acting as electron donors for the formation of photoactive electron donor‐acceptor (EDA) complexes with radical precursors and then as a CO acceptor via nitrogen radical cations to form carbamoyl radicals. Cross‐coupling of carbamoyl radicals with the acyl radicals that are formed in an alkene‐based relay process affords double aminocarbonylation products. [ABSTRACT FROM AUTHOR]

Higher‐order cycloadditions, particularly [8+2] cycloadditions, are a straightforward and efficient strategy for constructing significant medium‐sized architectures. Typically, configuration‐restrained conjugated systems are utilized as 8π‐components for higher‐order concerted cycloadditions. However, for this reason, 10‐membered monocyclic skeletons have never been constructed via catalytic asymmetric [8+2] cycloaddition with high peri‐ and stereoselectivity. Here, we accomplished an enantioselective [8+2] dipolar cycloaddition via the merger of visible‐light activation and asymmetric palladium catalysis. This protocol provides a new route to 10‐membered monocyclic architectures bearing chiral quaternary stereocenters with high chemo‐, peri‐, and enantioselectivity. The success of this strategy relied on the facile in situ generation of Pd‐containing 1,8‐dipoles and their enantioselective trapping by ketene dipolarophiles, which were formed in situ via a photo‐Wolff rearrangement. [ABSTRACT FROM AUTHOR]

Chiral catalysts tolerating photochemical reactions are in great demand for the vast development of visible‐light‐induced asymmetric synthesis. Now, chiral octahedral complexes based on earth‐abundant metal and chiral N4 ligands are reported. One well‐defined chiral CoII‐complex is shown to be an efficient catalyst in the visible‐light‐induced conjugated addition of enones by alkyl and acyl radicals, providing synthetically valued chiral ketones and 1,4‐dicarbonyls in 47–>99 % yields with up to 97:3 e.r. [ABSTRACT FROM AUTHOR]

Visible-light-driven organic photochemical reactions have attracted substantial attention from the synthetic community. Typically, catalytic quantities of photosensitizers, such as transition metal complexes, organic dyes, or inorganic semiconductors, are necessary to absorb visible light and trigger subsequent organic transformations. Recently, in contrast to these photocatalytic processes, a variety of photocatalyst-free organic photochemical transformations have been exploited for the efficient formation of carbon–carbon and carbon–heteroatom bonds. In addition to not requiring additional photocatalysts, they employ low-energy visible light irradiation, have mild reaction conditions, and enable broad substrate diversity and functional group tolerance. This review will focus on a summary of representative work in this field in terms of different photoexcitation modes. 1 Introduction 2 Visible Light Photoexcitation of a Single Substrate 3 Visible Light Photoexcitation of Reaction Intermediates 4 Visible Light Photoexcitation of EDA Complexes between Substrates 5 Visible Light Photoexcitation of EDA Complexes between Substrates and Reaction Intermediates 6 Visible Light Photoexcitation of Products 7 Conclusion and Outlook [ABSTRACT FROM AUTHOR]

Alkene bifunctionalizations are powerful tools for the rapid construction of structurally complex and valuable scaffolds, and such reactions typically involve the use of transition‐metal catalysts or organocatalysts. Here, we report for the first time a photogenerated neutral nitrogen radical catalyzed intermolecular alkene bifunctionalization by using allyl sulfones as the source of both the carbon and the sulfone functionalities under mild conditions. The key to the success of this protocol involves the visible‐light‐mediated photocatalytic in situ generation of a nitrogen‐centered radical from the N‐(2‐acetylphenyl) benzenesulfonamide catalyst, and its activation of the allyl sulfones to generate reactive species. The preliminary control experiments supported the postulated mechanism. [ABSTRACT FROM AUTHOR]

Abstract: The control of selectivity in the reactions of the highly reactive open‐shell carbon radicals is an attractive but often challenging task. Building on the strategy of photoinduced iminyl radical‐mediated C−C bond cleavage, we have developed photocatalytic neophyl rearrangement and reduction of distal carbon radicals under visible light irradiation of O‐acyl oximes. This mild protocol tolerates a wide range of readily available O‐acyl oximes, enabling facile synthesis of diversely substituted α,β‐unsaturated nitriles and β‐functionalized saturated nitriles in a highly selective manner. [ABSTRACT FROM AUTHOR]

Abstract: A visible light‐induced photocatalytic radical addition/cyclization reaction of o‐vinyl‐N‐alkoxybenzamides has been accomplished for efficient synthesis of diversely functionalized CF3‐containing iminoisobenzofurans. This external oxidant‐free and mild protocol features ready availability of starting materials, excellent regioselectivity, good substrate scope and functional group tolerance. [ABSTRACT FROM AUTHOR]

Bicarbonyl-substituted sulfur ylide is a useful, but inert reagent in organic synthesis. Usually, harsh reaction conditions are required for its transformation. For the first time, it was demonstrated that a new, visible-light photoredox catalytic annulation of sulfur ylides under extremely mild conditions, permits the synthesis of oxindole derivatives in high selectivities and efficiencies. The key to its success is the photocatalytic single-electron-transfer (SET) oxidation of the inert amide and acyl-stabilized sulfur ylides to reactive radical cations, which easily proceeds with intramolecular C−H functionalization to give the final products. [ABSTRACT FROM AUTHOR]

Photocatalysis enables the cascade reactions of indoles and CBr4 in MeOH through a C(sp2)H functionalization/methanolysis sequence. The title reaction provides an efficient access to indole 2- and 3-carboxylates in a single operation (no preinstallation of protecting as well as directing groups was required) with good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Visible-light-induced photocatalytic decarboxylative alkynylations of carboxylic acids have been developed for the first time. The reaction features extremely mild conditions, broad substrate scope, and avoids additional oxidants. Importantly, a decarboxylative carbonylative alkynylation has also been carried out in the presence of carbon monoxide (CO) under photocatalytic conditions, which affords valuable ynones in high yields at room temperature. [ABSTRACT FROM AUTHOR]

An unprecedented phototandem catalysis based on a single iridium photocatalyst has been successfully developed. This powerful strategy consists of two mechanistically distinct catalytic cycles, namely, photocatalytic energy transfer (ET) and single electron transfer (SET). The novel protocol allows a rapid and efficient construction of biologically and synthetically important 3-ester-3- hydroxy-2-oxindole derivatives from readily available diazoamides through a cyclization/aerobic oxidation sequence under very mild conditions. [ABSTRACT FROM AUTHOR]

A visible light-induced photocatalytic intramolecular cyclization of styryl azides has been developed in the presence of the ruthenium complex Ru(bpy)3Cl2 (0.5 mol%) as photocatalyst at room temperature. The present photocatalytic strategy features operational simplicity as well as high functional group tolerance, and provides a facile access to various 2-substituted N-free indoles in good to excellent yields. Importantly, the present process can employ sunlight as the light source to afford the corresponding products without loss of reaction efficiency. [ABSTRACT FROM AUTHOR]

A novel method for the synthesis of 1,4-diketones from β-ketosulfones was developed by means of a visible light-induced CS bond activation process. Symmetrical and unsymmetrical 1,4-diketones can be easily prepared in moderate to good yields. [ABSTRACT FROM AUTHOR]

All lit up: A novel and efficient desulfonylation method of tosyl amides has been developed by means of visible ‐ light ‐ promoted reductive cleavage of NS bonds. This method has a broad substrate scope, good functional group tolerance, and excellent yields. [ABSTRACT FROM AUTHOR]

Visible-light photoredox catalysis has attracted tremendous interest within the synthetic community. As such, the activation mode potentially provides a more sustainable and efficient platform for the activation of organic molecules, enabling the invention of many controlled radical-involved reactions under mild conditions. In this context, amide synthesis via the strategy of photoredox catalysis has received growing interest due to the ubiquitous presence of this structural motif in numerous natural products, pharmaceuticals and functionalized materials. Employing this strategy, a wide variety of amides can be prepared effectively from halides, arenes and even alkanes under irradiation of visible light. These methods provide a robust alternative to well-established strategies for amide synthesis that involve condensation between a carboxylic acid and amine mediated by a stoichiometric activating agent. In this review, the representative progresses made on the synthesis of amides through visible light-mediated radical reactions are summarized. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Catalytic four‐component radical carbonylation of unactivated alkenes has recently been recognized as a robust protocol for rapid construction of various structurally diverse carbonyl compounds. Given the significance of fluorine‐containing groups, this reaction class has been extensively applied to assembly of a variety of perfluoroalkyl carboxylic acid derivatives by transition metal catalysis. Herein, we report a visible‐light‐driven radical relay 1,2‐perfluoroalkylation aminocarbonylation of unactivated alkenes using CO gas as carbonyl source and 4CzIPN as organic photocatalyst. A wide range of alkenes and amines were well tolerated, providing the valuable β‐perfluoroalkylated amides with generally good yields and high chemoselectivity. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Organophosphorus compounds have attracted continuous attention in materials science, agrochemical and pharmaceutical fields due to their unique bioactivities. Thus, the development of novel and robust manners for the construction new C P bond has therefore gained great interests in synthetic organic chemistry. Because of their intrinsic sustainability and green chemistry character, visible light-induced photoredox catalysis has been widely applied in the construction of new chemical bonds, including the formation of C P bond. In this review, we summarized recent achievements in C P bond formation reactions initiated by visible light-induced photoredox catalysis, which mainly focusing on the discussion of reaction design and the mechanism. [ABSTRACT FROM AUTHOR]

Visible ‐ Light Photocatalysis The photocatalytic activation of the inert amide and acyl ‐ stabilized sulfur ylides are accomplished for the first time. Usually, the activation of this kind of sulfur ylides occurs under harsh reaction conditions. This visible ‐ light ‐ driven photoredox protocol can realize the construction of oxindole derivatives under extremely mild conditions. The key to its success is the photocatalytic single ‐ electron ‐ transfer (SET) oxidation of the inert sulfur ylides to reactive radical cations, which easily proceeds with intramolecular C−H functionalization to give the final products. For more details, see the Communication by L. ‐ Z Wu, W. ‐ J. Xiao et al. on page 8432 ff. [ABSTRACT FROM AUTHOR]