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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]

The C(sp3)–N bond is ubiquitous in natural products, pharmaceuticals, biologically active molecules and functional materials. Consequently, the development of practical and efficient methods for C(sp3)–N bond formation has attracted more and more attention. Compared to the conventional ionic pathway-based thermal methods, photochemical processes that proceed through radical mechanisms by merging photoredox and transition-metal catalyses have emerged as powerful and alternative tools for C(sp3)–N bond formation. In this review, recent advances in the burgeoning field of C(sp3)–N bond formation via metallaphotoredox catalysis have been highlighted. The contents of this review are categorized according to the transition metals used (copper, nickel, cobalt, palladium, and iron) together with photocatalysis. Emphasis is placed on methodology achievements and mechanistic insight, aiming to inspire chemists to invent more efficient radical-involved C(sp3)–N bond-forming reactions. [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]

Organic molecules bearing chiral sulfur stereocenters exert a great impact on asymmetric catalysis and synthesis, chiral drugs, and chiral materials. Compared with acyclic ones, the catalytic asymmetric synthesis of thio‐heterocycles has largely lagged behind due to the lack of efficient synthetic strategies. Here we establish the first modular platform to access chiral thio‐oxazolidinones via Pd‐catalyzed asymmetric [3+2] annulations of vinylethylene carbonates with sulfinylanilines. This protocol is featured by readily available starting materials, and high enantio‐ and diastereoselectivity. In particular, an unusual effect of a non‐chiral supporting ligand on the diastereoselectivity was observed. Possible reaction mechanisms and stereocontrol models were proposed. [ABSTRACT FROM AUTHOR]

The construction of an all‐in‐one catalyst, in which the photosensitizer and the transition metal site are close to each other, is important for improving the efficiency of metallaphotoredox catalysis. However, the development of convenient synthetic strategies for the precise construction of an all‐in‐one catalyst remains a challenging task due to the requirement of precise installation of the catalytic sites. Herein, we have successfully established a facile bottom‐up strategy for the direct synthesis of Ni(II)‐incorporated covalent organic framework (COF), named LZU‐713@Ni, as a versatile all‐in‐one metallaphotoredox catalyst. LZU‐713@Ni showed excellent activity and recyclability in the photoredox/nickel‐catalyzed C−O, C−S, and C−P cross‐coupling reactions. Notably, this catalyst displayed a better catalytic activity than its homogeneous analogues, physically mixed dual catalyst system, and, especially, LZU‐713/Ni which was prepared through post‐synthetic modification. The improved catalytic efficiency of LZU‐713@Ni should be attributed to the implementation of bottom‐up strategy, which incorporated the fixed, ordered, and abundant catalytic sites into its framework. This work sheds new light on the exploration of concise and effective strategies for the construction of multifunctional COF‐based photocatalysts. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Ureas are widely used in drugs, materials and catalysts because of their diamide structure, which can form strong hydrogen bonds. Therefore, it is of great scientific significance to develop efficient and green methods for the synthesis of urea compounds, especially unsymmetrical ureas. Here, we have disclosed novel and highly efficient three‐component coupling reactions of organic halides, sodium cyanate and amines enabled by nickel/photoredox dual catalysis for the preparation of unsymmetrical ureas. The reaction features simple and safe operations, broad substrate scopes, and product diversities. It allows the facile synthesis of N‐aryl/vinyl ureas from readily available, user‐friendly feedstocks under mild conditions (27 examples, 36%—98% yields). In addition, this method is further derived to alcohols as nucleophiles to synthesize a series of carbamates (15 examples, 40%—95% yields). The mechanism experiment shows that the isocyanate produced by the coupling of halide and sodium cyanate may be the key intermediate in this reaction. [ABSTRACT FROM AUTHOR]

Vinyldiazo compounds are one of the most important synthons in the construction of a cyclic ring. Most photochemical transformations of vinyldiazo compounds are mainly focusing on utilization of their C═C bond site, while reactions taking place at terminal nitrogen atom are largely unexplored. Herein, a photocatalytic cascade radical cyclization of LBRs with vinyldiazo reagents through sequential B─N/C─N bond formation is described. The reaction starts with the addition of LBRs (Lewis base–boryl radicals) at diazo site, followed by intramolecular radical cyclization to access a wide range of important boron‐handled pyrazoles in good to excellent yields. Control experiments, together with detailed mechanism studies well explain the observed reactivity. Further studies demonstrate the utility of this approach for applications in pharmaceutical and agrochemical research. [ABSTRACT FROM AUTHOR]

The exploration of value‐added conversions of naturally abundant amino acids has received considerable attention from the synthetic community. Compared with the well‐established asymmetric decarboxylative transformation, the asymmetric deaminative transformation of amino acids still remains a formidable challenge, mainly due to the lack of effective strategies for the C−N bond activation and the potential incompatibility with chiral catalysts. Here, we disclose a photoinduced Cu‐catalyzed asymmetric deaminative coupling reaction of amino acids with arylboronic acids. This new protocol provides a series of significant chiral phenylacetamides in generally good yields and excellent stereoselectivity under mild and green conditions (42–85 % yields, up to 97 % ee). Experimental investigations and theoretical calculations were performed to reveal the crucial role of additional phenols in improving catalytic efficiency and enantiocontrol. [ABSTRACT FROM AUTHOR]

Transition‐metal‐catalyzed radical relay cross‐coupling reactions of 1,3‐dienes have recently emerged as one of the most powerful methods for construction of structurally diverse allylic compound in a single chemical step. However, there still has been limited success in expanding substrate scope of radical precursors and coupling partners, as well as exploring catalytic asymmetric variants. Herein, we report a copper‐catalyzed enantioselective three‐component 1,2‐alkylesterification of 1,3‐dienes using cycloalkyl hydroperoxides as the carbonyl‐containing alkyl radical sources and carboxylic acids as O‐nucleophiles under mild and redox‐neutral conditions. This protocol features broad substrate scope and good functional group tolerance with respect to each component, providing practical access to a variety of distally keto‐functionalized allylic esters with high enantioselectivity. Mechanistic studies suggest the involvement of a sequential radical relay and C−O cross‐coupling in this three‐component radical reaction. [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]

Keywords: chiral allene; medium-sized ring; cycloaddition; Cope rearrangement; asymmetric catalysis EN chiral allene medium-sized ring cycloaddition Cope rearrangement asymmetric catalysis 1845 1851 7 09/15/23 20231004 NES 231004 Graph 1 Introduction Allene is a unique functional group with a three-carbon structure consisting of two I sp i SP 2 sp -hybridized terminal carbons and one I sp i -hybridized inner carbon (Scheme 1a). Since the correct structure and axial chirality of allenes was first predicted by the pioneer van't Hoff in 1875, [2] allenes have attracted continuous research interest from synthetic chemists for over a century, driven by the curiosity of their unique structure. [24] Another method to synthesize the 1,3-endocyclic allenes is the cyclization of skillfully designed acyclic allenes; but this is not applicable to the preparation of cyclic allenes with smaller rings. [Extracted from the article]

Metal‐polarized aza‐ortho‐quinone methides (aza‐o‐QMs) are a unique and efficient handle for azaheterocycle synthesis. Despite great achievements, the potential of these reactive intermediates has not yet been fully exploited, especially the new reaction modes. Herein, we disclosed an unprecedented dearomatization process of metal‐polarized aza‐o‐QMs, affording transient dearomatized spiroaziridine intermediates. Based on this serendipity, we accomplished three sequential dearomatization‐rearomatization reactions of benzimidazolines with aza‐sulfur ylides, enabling the divergent synthesis of bis‐nitrogen heterocycles with high efficiency and flexibility. Moreover, experimental and theoretical studies were performed to explain the proposed mechanisms and observed selectivity. Further cellular evaluation of the dibenzodiazepine products identified a hit compound for new antitumor drugs. [ABSTRACT FROM AUTHOR]

Ring‐opening transformations of donor‐acceptor (D‐A) cyclopropanes enable the rapid assembly of complex molecules. However, the enantioselective formation of chiral quaternary stereocenters using substrates bearing two different acceptors remains a challenge. Herein, we describe the first palladium‐catalyzed highly diastereo‐ and enantioselective (3+2) cycloaddition of vinyl cyclopropanes bearing two different electron‐withdrawing groups, a subset of D‐A cyclopropanes. The key to the success of this reaction is the remote stereoinduction through hydrogen bond from chiral ligands, which thereby addressed the aforementioned challenge. A variety of chiral five‐membered heterocycles were produced in good yields and with high stereoselectivity (up to 99 % yields, 99 : 1 er and >19 : 1 dr). In‐depth mechanistic investigations, including control experiments and theoretical calculations, revealed the origin of the stereoselectivity and the importance of H‐bonding in stereocontrol. [ABSTRACT FROM AUTHOR]

Concise synthesis of eight-membered lactones, a kind of medium-sized heterocycles widespread in many bioactive natural products, is highly significant. However, it still remains a challenge due to unfavorable entropic factor and transannular interaction. Herein, we disclose an enantioselective synthesis of eight-membered lactones through a Pd-catalyzed asymmetric (6 +2) dipolar annulation of vinyl oxetanes and α-diazo ketones (20 examples, up to 93% yield and 95:5 er). This reaction features simple operation, mild conditions and good enantiocontrol, especially the challenging chiral all-carbon quaternary stereocenter. A newly developed chiral hybrid P,S ligand and the in-situ photo-generation of ketene dipolarophiles are crucial to this success. [ABSTRACT FROM AUTHOR]