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A copper‐catalyzed C4‐selective addition of silicon nucleophiles released from an Si−B reagent to prochiral pyridinium triflates is reported. The dearomatization proceeds with excellent enantioselectivity using Cu(CH3CN)4PF6 as the precatalyst and (R,R)‐Ph‐BPE (1,2‐bis[(2R,5R)‐2,5‐diphenylphospholan‐1‐yl]ethane) as the chiral ligand. A carbonyl group at C3 is required for this, likely acting a weak donor group to preorganize and direct the nucleophilic attack towards C4. The resulting 4‐silylated 1,4‐dihydropyridines can be further converted into functionalized piperidine derivatives. [ABSTRACT FROM AUTHOR]

Although dearomative functionalizations enable the direct conversion of flat aromatics into precious three‐dimensional architectures, the case for simple arenes remains largely underdeveloped owing to the high aromatic stabilization energy. We herein report a dearomative sequential addition of two nucleophiles to arene π‐bonds through umpolung of chromium–arene complexes. This mode enables divergent dearomative carbonylation reactions of benzene derivatives by tolerating various nucleophiles in combination with alcohols or amines under CO‐gas‐free conditions, thus providing modular access to functionalized esters or amides. The tunable synthesis of 1,3‐ or 1,4‐cyclohexadienes as well as the construction of carbon quaternary centers further highlight the versatility of this dearomatization. Diverse late‐stage modifications and derivatizations towards synthetically challenging and bioactive molecules reveal the synthetic utility. A possible mechanism was proposed based on control experiments and intermediate tracking. [ABSTRACT FROM AUTHOR]

Catalytic olefin hydroamination reactions are some of the most atom‐economical transformations that bridge readily available starting materials–olefins and high‐value‐added amines. Despite significant advances in this field over the last two decades, the formal hydroamination of nonactivated aromatic compounds remains an unsolved challenge. Herein, we report the extension of olefin hydroamination to aromatic π‐systems by using arenophile‐mediated dearomatization and Cu‐catalysis to perform 1,2‐hydroamination on nonactivated arenes. This strategy was applied to a variety of substituted arenes and heteroarenes to provide general access to structurally complex amines. We conducted DFT calculations to inform mechanistic understanding and rationalize unexpected selectivity trends. Furthermore, we developed a practical, scalable desymmetrization to deliver enantioenriched dearomatized products and enable downstream synthetic applications. We ultimately used this dearomative strategy to efficiently synthesize a collection of densely functionalized small molecules. [ABSTRACT FROM AUTHOR]

A new method for the intramolecular electrophilic ipso -cyclization of alkynes with triflic anhydride-activated sulfoxides, followed by demethylation with triethylamine in one pot, is described for the synthesis of 3-thiospiro[4.5]-decatrienones in moderate to good yields. This method provides a facile strategy for assembling the sulfur-substituted spirocyclic compounds. [ABSTRACT FROM AUTHOR]

An efficient catalytic asymmetric dearomatizing amination of 2-naphthols and phenols catalyzed by N,N′-dioxide-copper(I) complex as a chiral catalyst was presented. A variety of optically active β-naphthalenone compounds with a nitrogen-containing quaternary carbon stereocenter were obtained with high yield and enantioselectivity under mild reaction conditions. Mechanistic studies indicated that this Csp2–N dearomatizing coupling proceeds via 1,3-reductive elimination of phenolate-CuIII-amino intermediate in five-membered ring transition states. The origin of enantioselectivity has also been elucidated based on density functional theory calculations. [ABSTRACT FROM AUTHOR]

A catalytic strategy towards the tribromide‐catalyzed dearomative spirocyclization reaction is described employing tetrabutylammonium bromide (TBAB) and oxone as an oxidising agent. This methodology leads to the exclusive formation of spirofurano dienones without rearomatization or halogenation. Our group has been on trails of tribromide‐catalyzed dearomative transformation during the last decade, and now this exhibits the first report which delivers high functional group tolerance and broad substrate scope with excellent yield (up to 99 %) and good diastereoselectivity (dr up to 14 : 1). The oxidation of naphthols as well as phenols is achieved under this mild conditions. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Functionalized free radical addition/cyclization reactions represent an efficient way for introducing new functionality or coupling fragments to molecules. Ynones are good regional selectivity radical acceptors in organic synthesis, and many of bio‐relevant cyclic compounds could be easily obtained by direct radical cyclization reaction. Here, we report a photocatalytic cascade radical addition of biaryl ynones, for the divergent synthesis of privileged carbon cycles. Additionally, further transformation of the multi‐functional group product into a variety of other derivatives demonstrates the synthetic value of this developed method. [ABSTRACT FROM AUTHOR]

Spirocycles are important structural motifs, found in natural and pharmaceutical compounds, which have attracted considerable interest in modern drug discovery research. Herein, we describe the development of a visible light‐mediated ipso‐cyclization of amino acid derivatives with N‐(2‐phenyl)benzoyl groups, allowing easy access to a variety of spirocyclohexadienes. The addition of water was found to be beneficial in promoting the reaction progress. Investigation of the substrate scope revealed that incorporating an electron‐donating moiety at the 3′‐position of the biphenyl group resulted in a more favorable outcome for spirocycle formation. [ABSTRACT FROM AUTHOR]

Iodine-mediated oxidative annulations of N -benzyl-propiolamides are disclosed for the first time, providing either azaspiro[5.5]undecatrienones via dearomative ipso -annulation or benzo[ c ]azepinones through ortho -annulation. The selective construction of the aforementioned products is based on the ceric ammonium nitrate (CAN)-promoted divergent reactivity of the propiolamide, directed by the substituents on the phenyl ring of the N -benzyl group. [ABSTRACT FROM AUTHOR]

We demonstrated herein an electrochemical dearomatizative alkylation of Katritzky salts, wherein Katritzky salts were harnessed as both radical acceptors and donors. A wide range of privileged dihydropyridine scaffolds was constructed with good to excellent yields. Cyclic voltammetry (CV) and electron paramagnetic resonance (EPR) results confirmed the key intermediates-dihydropyridine radicals and gram-scale reaction highlighted the practical and sustainable feature of the newly developed protocol.

In this study, we unveil a novel method for the asymmetric dearomatization of indoles under cobalt/photoredox catalysis. By strategically activating C−H bonds of amides and subsequent migratory insertion of π‐bonds present in indole as reactive partner, we achieve syn‐selective tetrahydro‐5H‐indolo[2,3‐c]isoquinolin‐5‐one derivatives with excellent yields and enantiomeric excesses of up to >99 %. The developed method operates without a metal oxidant, relying solely on oxygen as the oxidant and employing an organic dye as a photocatalyst under irradiation. Control experiments and stoichiometric studies elucidate the reversible nature of the enantiodetermining C−H activation step, albeit not being rate‐determining. This study not only expands the horizon of cobalt‐catalyzed asymmetric C−H bond functionalization, but also showcases the potential synergy between cobalt and photoredox catalysis in enabling asymmetric synthesis of complex molecules. [ABSTRACT FROM AUTHOR]

This article explores the use of chromium-promoted dearomative hydrocyanoalkylation in organic synthesis. The authors emphasize the versatility of the cyano group and the potential for using simple alkylnitriles as cost-effective sources. They acknowledge the challenges of dearomatization reactions and the limited range of current methods. The authors present their own research on the efficient dearomative hydrocyanoalkylation of chromium-bound (hetero)arenes using simple alkylnitriles, with a focus on optimizing reaction conditions. This research has the potential to expand the scope of dearomative hydrocyanoalkylation reactions and provide new synthetic building blocks. Additionally, the article discusses a new method for synthesizing complex cyclohexadiene compounds using a chromium-mediated reaction. The authors demonstrate the broad applicability of the reaction by successfully synthesizing various arenes and heteroarenes with different substituents and functional groups. They also extend the methodology to include the synthesis of deuterated cyclohexadienes and the transformation of the products into more structurally complex compounds. The authors highlight the potential applications of this method in the synthesis of bioactive natural products and alkaloids. [Extracted from the article]

The article discusses the challenges and strategies involved in the dearomatization of α-unsubstituted β-naphthols in organic synthesis. It explores various methods, including catalytic reduction reactions, Lewis acid catalysis, transition-metal-catalyzed reactions, and gold-catalyzed reactions. These methods offer efficient ways to synthesize complex spirocyclic molecules and functional spiro polymers. The article also acknowledges the limitations and challenges associated with these reactions and predicts the discovery of new strategies for catalytic asymmetric dearomatization reactions in the future. [Extracted from the article]

In this study, we present an efficient and straightforward dearomative hydroalkylation of indoles. By utilizing alkanes or ethers as alkyl radical sources and employing TBADT as a cost‐effective photocatalyst for direct hydrogen atom transfers (HAT), we achieved successful conversion of these heterocyclic derivatives into 2‐alkylindolines with good to excellent yields and high diastereoselectivity under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Dearomative partial reduction is an extraordinary approach for transforming benzenoid arenes and has been well‐known for many decades, as exemplified by the dehydrogenation of Birch reduction and the hydroarylation of Crich addition. Despite its remarkable importance in synthesis, this field has experienced slow progress over the last half‐century. However, a revival has been observed with the recent introduction of electrochemical and photochemical methods. In this Minireview, we summarize the recent advancements in dearomative partial reduction of benzenoid arenes, including dihydrogenation, hydroalkylation, arylation, alkenylation, amination, borylation and others. Further, the intriguing utilization of dearomative partial reduction in the synthesis of natural products is also emphasized. It is anticipated that this Minireview will stimulate further progress in arene dearomative transformations. [ABSTRACT FROM AUTHOR]

Replacing crude oil as the primary industrial source of carbon‐based chemicals has become crucial for both environmental and resource sustainability reasons. In this scenario, wood arises as an excellent candidate, whilst depolymerization approaches have emerged as promising strategies to unlock the lignin potential as a resource in the production of high‐value organic chemicals. However, many drawbacks, such as toxic solvents, expensive catalysts, high energy inputs, and poor product selectivity have represented major challenges to this task. Herein, we present an unprecedented approach using electrocatalysis for the simultaneous depolymerization and dearomatization of lignin in aqueous medium under ambient conditions. By employing water/sodium carbonate as a solvent system, we demonstrated a pathway for selectively depolymerizing lignin under reductive electrochemical conditions using carbon as an electrocatalyst. After reductive electrocatalysis, the presence of aromatic compounds was no longer detected via nuclear magnetic resonance (NMR) spectroscopy. Further characterization by NMR, FTIR spectroscopy, and mass spectrometry revealed the major presences of sodium levulinate, sodium 4‐hydroxyvalerate, sodium formate, and sodium acetate as products. By achieving a complete dearomatization, valuable aliphatic intermediates with enhanced reactivity were selectively obtained, opening new avenues for further synthesis of many different organic chemicals, and contributing to a more sustainable and circular economy. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The development of efficient and sustainable methods to obtain spirocyclic compounds is of significance as these structures are widely found in pharmaceuticals and agrochemicals. Herein, we disclose an electrochemical dearomative spirocyclization of N‐acyl sulfonamides in a continuous‐flow cell. The reaction is simple and efficient without external catalysts or supporting electrolytes and could be applied in a decagram‐scale synthesis. [ABSTRACT FROM AUTHOR]

Synthesis of nitro-substituted [1,2,4]triazolo[1,5-a]pyrimidines based on oxidative cyclization of the corresponding nitropyrimidinyl hydrazones of aromatic aldehydes was developed. The reactions of 2-aryl-6-nitro-[1,2,4]triazolo[1,5-a]pyrimidines and their structural analogs (2-aryl-6,8-dinitro-[1,2,4]triazolo[1,5-a]pyridines) with different C-nucleophiles were studied. Nucleophilic addition to the pyridine and pyrimidine rings carried out under mild base-free conditions gave new stable 1.5-dihydro-[1,2,4]triazolo [1,5-a]-pyridines and 1.5-dihydro-[1,2,4]triazolo[1,5-a]pyrimidines in the yields up to 94%. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The development of efficient and sustainable methods to obtain spirocyclic compounds is of significance as these structures are widely found in pharmaceuticals and agrochemicals. Herein, we disclose an electrochemical dearomative spirocyclization of N‐acyl sulfonamides in a continuous‐flow cell. The reaction is simple and efficient without external catalysts or supporting electrolytes and could be applied in a decagram‐scale synthesis. [ABSTRACT FROM AUTHOR]

A transition‐metal‐free dearomative aza‐spirocyclization reaction of 2,3‐disubstituted indoles is established by using molecular iodine under basic conditions. The required substrates were prepared via sequential Fisher indole synthesis and sulfonylation. This dearomatization reaction is amenable to gram‐scale synthesis, and provides access to various spiroindolenine derivatives from indole sulfonamide precursors. [ABSTRACT FROM AUTHOR]

A catalyst‐free intermolecular dearomatization reaction of β‐naphthols with hypervalent‐iodine‐based nitrooxylating reagent is reported. Various nitrooxylated β‐naphthalenones bearing a quaternary carbon stereogenic center were obtained smoothly in good to excellent yields (up to 87 %) under mild conditions. This method features mild conditions, broad substrate scope and excellent chemoselectivity. [ABSTRACT FROM AUTHOR]

Given the prevalence of heterocyclic scaffolds in drug‐related molecules, converting these highly modular heterocyclic scaffolds into structural diversified and dearomatized analogs is an ideal strategy for improving their physicochemical and pharmacokinetic properties. Here, we described an efficient method for silver carbene‐mediated dearomative N−N bond cleavage leading to skeletal hopping between indazole and 1,2‐dihydroquinazoline via a highly selective single‐carbon insertion procedure. Using this methodology, a series of dihydroquinazoline analogues with diarylmethylene‐substituted quaternary carbon centers were constructed with excellent yields and good functional group compatibility, which was further illustrated by the late‐stage diversification of important pharmaceutically active ingredients. DFT calculations indicated that the silver catalyst not only induces the formation of the silver carbene, but also activates the diazahexatriene intermediate, which plays a crucial role in the formation of the C−N bond. [ABSTRACT FROM AUTHOR]

A K2CO3 promoted spirocyclopropanation of thiazole‐derived oxadienes with bromomalonate via 1, 4‐addition‐induced dearomatization strategy has been developed. The pathway features a broad substrate scope, operational simplicity and high degree of synthetic efficiency to afford series of functionalized spiro‐cyclopropanation frameworks in 88 %–96 % yields, which enriches the research contents of thiazole‐derived oxadienes involved reactions. All products obtained herein contain two contiguous quaternary centers and their further synthetic applications are also demonstrated. [ABSTRACT FROM AUTHOR]

This article presents a new method for brominating and dearomatizing 2-methoxyphenols using N-bromosuccinimide (NBS). The authors found that this method allows for the introduction of bromo groups into the aromatic ring and their conversion into ortho-quinonemonoacetals (o-QMAs) in a single step. The use of NBS as an oxidant in the dearomatization reactions of 2-alkoxyphenols is significant because it is cost-effective and easy to handle. The authors conducted optimization experiments and successfully applied the method to various 2-methoxyphenols, demonstrating its broad applicability. They also explored the use of chlorinating agents as alternatives to brominating agents. The resulting o-QMAs have potential applications as synthetic building blocks. Ongoing research is being conducted in this area. [Extracted from the article]

An efficient dearomative (3 + 2) cycloaddition of para-quinamines and 2-nitrobenzofurans has been developed. This reaction proceeds smoothly under mild conditions and affords a series of benzofuro[3,2-b]indol-3-one derivatives in good to excellent yields (up to 98%) with perfect diastereoselectivities (all cases > 20:1 dr). The scale-up synthesis and versatile derivatizations demonstrate the potential synthetic application of the protocol. A plausible reaction mechanism is also proposed to account for the observed reaction process. This work represents the first instance of the N-triggered dearomative (3 + 2) cycloaddition of 2-nitrobenzofurans. [ABSTRACT FROM AUTHOR]

The Sc(OTf)3-catalyzed dearomative [5+1] annulations between readily available 3-aminophenols and O-alkyl ortho-oxybenzaldehydes were developed for synthesis of spiro[chromane-3,1′-cyclohexane]-2′,4′-dien-6′-ones. The "two-birds-with-one-stone" strategy was disclosed by the dearomatization of phenols and direct α-C(sp3)–H bond functionalization of oxygen through cascade condensation/[1,5]-hydride transfer/dearomative-cyclization process. In addition, the antifungal activity assay and derivatizations of products were conducted to further enrich the utility of the structure. [ABSTRACT FROM AUTHOR]

Dearomative spirocyclization reactions represent a promising means to convert arenes into three‐dimensional architectures; however, controlling the regioselectivity of radical dearomatization with nonactivated arenes to afford the spirocyclizative 1,2‐difunctionalization other than its kinetically preferred 1,4‐difunctionalization is exceptionally challenging. Here we disclose a novel strategy for dearomative 1,2‐ or 1,4‐amidoximation of (hetero)arenes enabled by direct visible‐light‐induced homolysis of N−NO bonds of nitrosamides, giving rise to various highly regioselective amidoximated spirocycles that previously have been inaccessible or required elaborate synthetic efforts. The mechanism and origins of the observed regioselectivities were investigated by control experiments and density functional theory calculations. [ABSTRACT FROM AUTHOR]

Dearomative intramolecular Diels–Alder/sulfur extrusion reaction of thiophenes with alkynes successfully afforded fluoranthenes in moderate to excellent yields. The proximity of both reactive sites fixed at the peri‐position of naphthalene would play an important role in the progress of this reaction. Tri(o‐tolyl)phosphine effectively suppressed the side reactions as a sulfur scavenger. [ABSTRACT FROM AUTHOR]

This study describes a method of synthesising pyridine, quinoline, and isoquinoline ketones using 2‐halogenated N‐heterocycles as the starting materials under mild reaction conditions. Considering the significance of pyridones in organic chemistry, developing novel, green synthetic strategies is highly desirable. The reaction employs H2O as the solvent and source of O, rendering it green, and it is simple to execute, with a broad substrate scope and an excellent functional group tolerance. [ABSTRACT FROM AUTHOR]

Access to complex three-dimensional molecular architectures via dearomatization of ubiquitous aryl rings is a powerful synthetic tool, which faces, however, an inherent challenge to overcome energetic costs due to the loss of aromatic stabilization energy. Photochemical methods that allow one to populate high-energy states can thus be an ideal strategy to accomplish otherwise prohibitive reaction pathways. We present an original dearomative rearrangement of heteroaryl acryloylallenamides that leads to complex fused tricycles. The visible-light-promoted method occurs under mild conditions and tolerates a variety of functional groups. According to DFT modeling used to rationalize the outcome of the cascade, the reaction involves a sequential [2+2] allene–alkene photocycloaddition, which is followed by a selective retro- [2+2] step that paves the way for the dearomatization of the heteroaryl partner. This scenario is original with respect to the reported photochemical reactivity of similar substrates and thus holds promise for ample future developments. [ABSTRACT FROM AUTHOR]

Herein, we achieved a green and efficient dearomatization for the synthesis of 2,3-functionalized polycyclic indolines in an electrochemical way. This avoiding of external oxidants and metals approach allowed various nucleophilic sources (Nu = anilines, TMSN3 and ROH) to perform the products, representing an environmentally benign means. Additionally, the continuous flow electrosynthesis and synthetic transformations also reveal the strong practicality of electrochemistry in organic synthesis. [ABSTRACT FROM AUTHOR]

Highly oxygenated cyclohexanes, including (amino)cyclitols, are featured in natural products possessing a notable range of biological activities. As such, these building blocks are valuable tools for medicinal chemistry. While de novo synthetic strategies have provided access to select compounds, challenges including stereochemical density and complexity have hindered the development of a general approach to (amino)cyclitol structures. This work reports the use of arenophile chemistry to access dearomatized intermediates which are amenable to diverse downstream transformations. Practical guidelines were developed for the synthesis of natural and non‐natural (amino)cyclitols from simple arenes through a series of strategic functionalization events. [ABSTRACT FROM AUTHOR]

The [1,2]‐Brook rearrangement stands as a potent technique for constructing complex molecules. In this study, we showcase its power in the dearomatization of aromatic N‐heterocycles. Through a concise four‐step process that integrates lithiation, nucleophilic addition, Brook rearrangement and dearomatization reaction, we demonstrate a versatile strategy for generating diverse non‐aromatic N‐heterocycles which exhibit ambident reactivities. Various acyl silanes, halo‐pyridines, and quinolines have been explored within this context. The synthetic utility of this methodology is demonstrated through the construction of complex architectures. [ABSTRACT FROM AUTHOR]

Bridged benzazepine scaffolds, possessing unique structural and physicochemical activities, are widespread in various natural products and drugs. The construction of these skeletons often requires elaborate synthetic effort with low efficiency. Herein, we develop a simple and divergent approach for constructing various bridged benzazepines by a photocatalytic intermolecular dearomatization of naphthalene derivatives with readily available α‐amino acids. The bridged motif is created via a cascade sequence involving photocatalytic 1,4‐hydroaminoalkylation, alkene isomerization and cyclization. Interestingly, the diastereoselectivity can be regulated through different reaction modes in the cyclization step. Moreover, aminohydroxylation and its further bromination have also been demonstrated to access highly functionalized bridged benzazepines. Preliminary mechanistic studies have been performed to get insights into the mechanism. This method provides a divergent synthetic approach for construction of highly functionalized bridged benzazepines, which have been otherwise difficult to access. [ABSTRACT FROM AUTHOR]

The skeletal ring expansion of heteroarenes through carbene insertion is gaining popularity in synthetic chemistry. Efficient strategies for heterocyclic ring expansion to access heterocycles containing a fluoroalkyl quaternary carbon center through fluoroalkyl carbene insertion are highly desirable because of their broad applications in medicinal chemistry. Herein, we report a general strategy for the dearomative one‐carbon insertion of azoles using fluoroalkyl N‐triftosylhydrazones as fluoroalkyl carbene precursors, resulting in ring‐expanded heterocycles in excellent yields with good functional‐group compatibility. The broad generality of this methodology in the late‐stage diversification of pharmaceutically interesting bioactive molecules and versatile transformations of the products has been demonstrated. [ABSTRACT FROM AUTHOR]

4-formyl phenols with electron donating groups in ortho-position react with active alkyl halides in three directions: Williamson reaction up to 48%, aromatic substitution of the formyl group up to 36%, and addition to the ortho-position with dearomatization of the ring up to 10%. The ratio of the products depends on the substituents in the benzene ring and the used alkali and additives. [ABSTRACT FROM AUTHOR]

This article provides an overview of recent advancements in the dearomative skeletal editing of mono-azaarenes, which are nitrogen-containing heterocycles commonly found in natural products and pharmaceuticals. The authors discuss various methods, such as Zincke-like reactions, aza-Buchner reactions, and photoinduced reactions, for breaking the aromaticity of azaarenes and reconstructing them into complex molecules. The article highlights the latest research and breakthroughs in these methods, including their limitations and mechanisms. It aims to inspire readers to explore more approaches to advance the development of skeletal editing of mono-azaarenes as a synthetic tool for accessing difficult-to-reach molecules. [Extracted from the article]

This study reports the first synthesis of tetrahydroquinaldic and tetrahydropicolinic amides using readily available quinolines and pyridines through dearomative difunctionalization and hydrolysis under transition‐metal‐ and reductant‐free conditions. The prepared amide products could be easily oxidized to the corresponding quinaldic and picolinic amides. Furthermore, the chemical reactivity of the amide group has been explored to develop convenient methods for their conversion to other common organic functional groups. [ABSTRACT FROM AUTHOR]

Despite the unique reactivity of vitamin B12 and its derivatives, B12‐dependent enzymes remain underutilized in biocatalysis. In this study, we repurposed the B12‐dependent transcription factor CarH to enable non‐native radical cyclization reactions. An engineered variant of this enzyme, CarH*, catalyzes the formation γ‐ and δ‐lactams through either redox‐neutral or reductive ring closure with marked enhancement of reactivity and selectivity relative to the free B12 cofactor. CarH* also catalyzes an unusual spirocyclization by dearomatization of pendant arenes to produce bicyclic 1,3‐diene products instead of 1,4‐dienes provided by existing methods. These results and associated mechanistic studies highlight the importance of protein scaffolds for controlling the reactivity of B12 and expanding the synthetic utility of B12‐dependent enzymes. [ABSTRACT FROM AUTHOR]

This article explores the synthesis of spirocyclic cyclohexadienones from hydroquinones and naphthols. The authors discovered that electron-rich hydroquinones and naphthols yielded the desired spiro-cycles in moderate to good yields. They also investigated the reaction's scope using different reactants and found that certain conditions favored the formation of [4+2]-fused ring products, while others favored [4+1]-dearomatization spiroannulation products. The authors proposed a mechanism for the reaction involving sequential Friedel-Crafts reactions and isomerization reactions, but noted that simple substituted phenols did not react under the current conditions. [Extracted from the article]

A transition‐metal‐free method is disclosed for the construction of selenylated spirocyclohexadienones via cascade cyclization/dearomatization reaction of aryl phenol‐tethered alkynes with diselenides. The high efficiency of this protocol was demonstrated by room temperature, simple reaction conditions, and the ability to enable a gram‐scale synthesis. The experiment results implied that the dearomatization process proceeded in a radical way. [ABSTRACT FROM AUTHOR]

This article discusses the use of electrochemistry as a sustainable and efficient method for the synthesis of spirooxacyclic compounds, which have biological and medicinal relevance. The authors optimize the reaction conditions and successfully synthesize various compounds with high yields. The reactions involve the formation of cyclic ethers and lactones from phenols and alcohols. The purification and characterization of the compounds are detailed, including their NMR spectra and MS data. The supporting information for the article is available online. [Extracted from the article]

We disclose a catalytic, enantioselective dearomative reaction of non‐functionalized 1‐naphthols, which poses a synthetic challenge to organic chemists because of the relative ease of rearomatization via the elimination of a proton. In this work, the direct dearomatization of non‐functionalized 1‐naphthols was achieved through a chiral phosphoric acid (CPA) catalyzed enantioselective dearomative [4+2] cycloaddition reaction with in‐situ generated ortho‐quinone methides (o‐QMs). The reported convergent method allows the use of readily available simple 1‐naphthols without pre‐functionalization, furnishing a variety of naphthopyran derivatives in good yields (up to 96 %) and moderate to excellent enantioselectivities (up to >99 % ee) under mild reaction conditions. The observed regio‐, diastereo‐, and enantioselectivities are the keys to the success of the current strategy utilizing o‐QM as a diene surrogates, in combination with CPA catalysis. [ABSTRACT FROM AUTHOR]

Total syntheses of C11‐oxygenated Cephalotaxus alkaloids, fortuneicyclidins A and B, and cephalotine B, were achieved. The key for the synthesis is a Pd‐catalyzed dearomative spirocyclization of bromofurans with N‐tosylhydrazones, followed by acid‐mediated tandem transformation to construct the tetracyclic skeleton with the C11‐oxygen functional group. Chemo‐selective and catalytic functional group conversions of the tetracyclic intermediate completed the synthesis of fortuneicyclidins and cephalotine B in 8 and 9 steps, respectively. [ABSTRACT FROM AUTHOR]