Regiodivergent construction of medium-sized heterocycles from vinylethylene carbonates and allylidenemalononitriles

Asymmetric Amination of 1,2-Diol through Borrowing Hydrogen: Synthesis of Vicinal Amino α-Tertiary Alcohol

Methods to prepare vicinal amino alcohols are important because of their presence in biologically active compounds. Despite the development of various methods for vicinal amino alcohol synthesis, C(sp3)-rich oxygen-containing β-amine compounds continue to pose great challenge. While ring-opening reaction of epoxides with amine nucleophile is the prime method for vicinal amino alcohol preparation, epoxides are highly reactive and sometimes difficult to make, resulting in drawbacks regarding selectivity of this approach. Here, we report a catalytic enantio-convergent amination of α-tertiary 1,2-diols for the efficient access to vicinal amino α-tertiary alcohols. The racemic α-tertiary 1,2-diol substrates of different alkyl/aryl or alkyl/alkyl backbone, can be converted to chiral vicinal amino α-tertiary alcohols through diphenyl phosphate-mediated RuCl3 catalysed asymmetric borrowing hydrogen (ABH) pathway. This simple ABH reaction can be scaled up to the synthesis of chiral ligands, synthetic intermediates, and other medicinally-relevant compounds. Overall, this catalytic redox-neutral procedure broadens the scope of Ru-catalysed amination of alcohols and discloses an underexplored step- and atom-economical synthetic strategy for the synthesis of vicinal amino α-tertiary alcohols and provides a practicable alternative to the present benchmark procedures.

3-Oxabicyclo[3.1.1]heptanes as Isosteres of meta-Substituted Benzene Rings

Replacement of the aromatic rings in drug candidates with isosteric rigid sp3-rich scaffolds can improve physicochemical properties, increase the chance of progressing the molecule in development, and open new chemical space. Isosteres of meta-substituted benzenes remain challenging due to the difficulty of mimicking the exit vector angles and bond distances. Herein, we report the synthesis of 1,5-disubstituted 3-oxabicyclo[3.1.1]heptanes (oxa-BCHeps), which can serve as saturated isosteres of meta-substituted phenyl rings with a similar geometric arrangement. This structural motif can be obtained under mild reaction conditions via acid-mediated isomerization of (2-oxaspiro[3.3]heptan-6-yl)methanols using catalytic quantities of pyridinium chloride (PyrHCl). We demonstrate the utility of this methodology by preparing various building blocks for use in medicinal chemistry and incorporating 3-oxa-BCHep into the anticancer drug sonidegib, improving its physicochemical properties, such as permeability, metabolic stability, and solubility.

Asymmetric Formal [5 + 2] Annulation of 3-Hydroxyquinolinones and Vinylethylene Carbonates through Pd/Cu Tandem Catalysis

The asymmetric [5 + 2] cycloaddition of VECs remains to be comparatively rare. Herein, we reported an enantioselective formal [5 + 2] annulation of 3-hydroxyquinolinones and vinylethylene carbonates (VECs) through Pd- and Cu-catalyzed tandem allylation/asymmetric [1,3]-rearrangement/hemiketalization sequences. The strategy exhibits good substrate tolerance, affording a wide range of tricyclic quinolinones bearing two adjacent quaternary stereocenters in moderate to good yields with excellent enantioselectivities.

Palladium-Catalyzed [7 + 5] and Higher-Order Annulations of Oxa-1,n-dipoles: Synthesis of 12- to 15-Membered Lactones

Macrolactones are commonly found in natural products and pharmaceuticals. Herein, we present Pd-catalyzed [7 + 5] and higher-order annulations between unprecedented oxa-1,n-dipoles (n = 7-9) with active enol lactones. This protocol enables the rapid synthesis of complex 12 to 15-membered lactones bearing internal E-alkenes. Density functional theory calculations have revealed the favorable reaction pathway and identified coordination interactions between active enol lactones and palladium centers of π-allyl dipole species as key factors in manipulating these dipoles in annulations.

Cycloadditions of 5-Vinyloxazolidine-2,4-diones: A Straightforward Access to the (Thio)hydantoin Scaffold

A palladium-catalyzed (3 + 2) cycloaddition between 5-vinyloxazolidine-2,4-diones (VOxD) and (thio)isocyanates is described. Under optimized conditions, an array of (thio)hydantoins was readily prepared, and an enantioselective version of this transformation was then studied. To illustrate the importance of this method, a concise synthesis of two bioactive compounds, nirvanol and mephenytoin, was carried out. This work emphasizes the synthetic potential of VOxD as useful precursors of zwitterionic aza-π-allylpalladiumII intermediates.

Type of Tetrahydronaphthalene-Fused 1,5-Dipoles and Their Application in Polycyclic Compounds Synthesis

Palladium-catalyzed dipolar cycloaddition reactions represent an efficient strategy for the construction of cyclic compounds, with the development of novel dipolar precursors being a key focus. In this study, a new type of dipolar precursor was synthesized through the assembly of the vinylethylene carbonate unit and the tetrahydronaphthalene skeleton. This dipolar precursor can undergo [3 + 2], [5 + 4], and [5 + 2] cycloaddition reactions, leading to the construction of tetrahydronaphthalene-fused oxazolidin-2-ones, 1,5-oxazonines, and tetrahydrooxepines. In general, all of these reactions exhibited good reaction efficiency and functional group tolerance.

Chemo-, Regio- and Stereoselective Preparation of (Z)-2-Butene-1,4-Diol Monoesters via Pd-Catalyzed Decarboxylative Acyloxylation

(Z)-alkenes are useful synthons but thermodynamically less stable than their (E)-isomers and typically more difficult to prepare. The synthesis of 1,4-hetero-bifunctionalized (Z)-alkenes is particularly challenging due to the inherent regio- and stereoselectivity issues. Herein we demonstrate a general, chemoselective and direct synthesis of (Z)-2-butene-1,4-diol monoesters. The protocol operates within a Pd-catalyzed decarboxylative acyloxylation regime involving vinyl ethylene carbonates (VECs) and various carboxylic acids as the reaction partners under mild and operationally attractive conditions. The newly developed process allows access to a structurally diverse pool of (Z)-2-butene-1,4-diol monoesters in good yields and with excellent regio- and stereoselectivity. Various synthetic transformations of the obtained (Z)-2-butene-1,4-diol monoesters demonstrate how these synthons are of great use to rapidly diversify the portfolio of these formal desymmetrized (Z)-alkenes.

Phenoxaphosphonium Mixed Ylides in Ring Expansion Reaction

Treatment of mixed phosphonium-iodonium ylides featuring a six-membered phenoxaphosphonium fragment with aqueous tetrafluoroboronic acid induces a rearrangement, resulting in expansion of the phosphacycle and oxidation of the phosphorus atom. The target difficult-to-access dibenzo[b,f][1,4]oxaphosphepine oxides (3 examples) were isolated in excellent yields (up to 95%) as mixtures of stereoisomers. Hydrolysis of a five-membered mixed ylide, a dibenzophosphole derivative, predominantly preserves the phosphole system with cycle expansion occurring as a side process.

Palladium-catalyzed (Z)-selective allylation of phosphine oxides with vinylethylene carbonates to construct phosphorus allyl alcohols

Allylphosphine oxide compounds are important building blocks with broad applications in organic synthesis and pharmaceutical science. Herein, we report an unprecedented palladium-catalyzed allylation of phosphine oxides with vinylethylene carbonates, producing various phosphorus allyl alcohols in excellent yields with high Z-selectivity. In addition, gram-scale synthesis and further functional group transformations demonstrate the practical utility of this synthetic method.

Cyclic Diaryl λ3-Bromanes as a Precursor for Regiodivergent Alkynylation Reactions

Regiodivergent reactions are a fascinating tool to rapidly access molecular diversity while using identical coupling partners. We have developed a new approach for regiodivergent synthesis using the dual character of hypervalent bromines. In addition to the recently reported reactivity of hypervalent bromines as aryne precursors, the first transition metal-catalyzed reaction is reported. Accordingly, the development of these two complementary transformations allows for the alteration of regioselectivity to furnish both ortho- and meta-substituted alkynylation products. Mechanistic and computational studies show how these selectivities are controlled.

Palladium-Catalyzed [5 + 4] Cycloaddition of 4-Vinyl-4-Butyrolactones with N-Tosyl Azadienes: Construction of Nine-Membered Ring

In this paper, we reported the palladium-catalyzed formal [5 + 4] cycloaddition reactions between 4-vinyl-4-butyrolactones (VBLs) and azadienes. Under mild reaction conditions, a wide range of benzofuran-fused 9-membered heterocyclic compounds had been provided in moderate to excellent yields with exclusive regioselectivities and excellent diastereoselectivities. The practical applicability of the synthesis was demonstrated through scale-up reaction and further transformation.

Catalytic Domino Three-Component Synthesis of Functionalized Heterocycles from Carbon Dioxide

A catalytic domino, three-component reaction has been developed for the transformation of carbon dioxide into functionalized six-membered cyclic carbonates. The catalytic process combines an initial carboxylative cyclization of β-epoxy alcohols followed by an oxa-Michael reaction affording an unparalleled scope of heterocyclic structures. The wide range of functional groups, including free-alcohols, empowers the access to a range of products including C11-oxo-based bicyclic heterocycles. The versatility of these functionalized carbonates is further complemented by a series of synthetic diversifications. Control experiments are consistent with the first step of this domino process being promoted by a binary Lewis acid/base catalyst, while the second stage only requires catalytic base.

Construction of 3,4-Dihydroquinolone Derivatives through Pd-Catalyzed [4+2] Cycloaddition of Vinyl Benzoxazinanones with α-Alkylidene Succinimides

The construction of 3,4-dihydroquinolone derivatives has attracted a considerable amount of attention due to their extensive applications in medicinal chemistry. In this study, we present the Pd-catalyzed [4+2] cycloaddition of vinyl benzoxazinanones with α-alkylidene succinimides for the efficient synthesis of 3,4-dihydroquinolones. This approach presents numerous advantages, including the ready availability of starting materials, mild reaction conditions without the use of additional bases, and a wide range of substrates. In particular, all of the desired products can be easily afforded in high yields (≤99%) and excellent diastereoselectivities (>20:1). The practicality and reliability of this strategy were demonstrated by the successful scale-up synthesis and subsequent straightforward synthetic transformations.

Palladium-catalyzed ring-opening [5+2] annulation of vinylethylene carbonates (VECs) and C5-substituted Meldrum's acids: rapid synthesis of 7-membered lactones

A novel approach for the synthesis of unsaturated 7-membered lactones by Pd-catalyzed [5+2] dipolar cycloaddition of vinylethylene carbonates (VECs) and C5-substituted Meldrum's acid derivatives has been developed. Various Meldrum's acid derivatives worked well in this reaction under mild reaction conditions. A variety of 7-membered lactones can be accessed in a facile manner in moderate to good yields by employing easily prepared Meldrum's acid derivatives.

Dearomatization/Spiroannulation of Halophenols Enables the Forging of Contiguous Quaternary Carbon Cyclohexadienones

A dearomatization/spiroannulation process has been successfully achieved between simple halophenols and α,β-unsaturated olefins under mild reaction conditions. This transformation addresses the chemoselectivity issue in the dearomatizative transformation of phenol scaffolds (6π-electron) caused by the SEAr process, enabling the construction of versatile cyclohexadienone frameworks containing contiguous quaternary all-carbon centers in high yields. Further studies have provided valuable insights into the process, revealing that debromination/spiroannulation occurs through the SRN1 pathway.

Palladium-catalyzed decarboxylative α-allylation of thiazolidinones and azlactones with sulfonamido-substituted acyclic allylic carbonates

A palladium-catalyzed decarboxylative α-allylation of thiazolidinones and azlactones with aza-π-allylpalladium zwitterionic intermediates, in situ generated from sulfonamido-substituted allylic carbonates, is successfully developed. This method allows the formation of a series of structurally diverse 5-alkylated thiazolidinones and 2-piperidones under mild conditions in moderate to high yields (up to 99% yield).

Base-Promoted Formal (3 + 2) Cycloaddition of α-Halohydroxamates with Electron-Deficient Alkenyl-iminoindolines To Synthesize Spiro-indolinepyrrolidinones

Construction of pyrrolidinyl-spiroindoles with easily available starting materials has attracted considerable attention from the synthesis community and is in great demand. Here, we describe a base-promoted formal (3 + 2) cycloaddition of α-halohydroxamates with alkenyl-iminoindolines. The present methodology features mild reaction conditions and a broad substrate scope with up to 99% yield and excellent diastereoselectivity. The versatility of this approach is demonstrated through valuable synthetic transformations. Preliminary mechanistic studies shed light on the mechanism of this cycloaddition process.

Studies on the [4 + 2] cycloaddition and allylic substitution of indole-fused zwitterionic π-allylpalladium

The zwitterionic π-allylpalladium species, also known as dipoles, are important synthons widely used in various reactions including cycloaddition and allylic substitution. This study reported the development of a new indole-fused zwitterionic π-allylpalladium precursor compound and its application in [4 + 2] cycloaddition and allylic substitution reactions. As a result, the synthesis of pyrrolo[3,2,1-ij]quinazolin-3-one and 7-vinyl indole compounds was achieved with moderate to good yields. Notably, the allylic substitution reaction exhibited excellent regio- and stereoselectivity.

Diastereo- and Enantioselective Palladium-Catalyzed Cycloadditions of 5-Vinyloxazolidine-2,4-diones with Electrophilic Imines

Despite the importance of the 4-imidazolidinone scaffold in bioactive compounds or organocatalysts, methodologies to access these nitrogenated heterocycles remain scarce. This manuscript describes a novel preparation of 4-imidazolidinones via a diastereo- and enantioselective (3 + 2) cycloaddition between 5-vinyloxazolidine-2,4-diones (VOxD) and electrophilic imines under palladium catalysis. This work supports the synthetic potential of VOxD as a promising equivalent of the C-C(═O)-N synthon.

Gold and Palladium Relay Catalytic [4 + 4] Cycloadditions of Enynamides and γ-Methylene-δ-valerolactones: Diastereoselective Construction of Furan-Fused Azacyclooctanes

We report a highly efficient and diastereoselective gold and palladium sequential relay catalysis system for the synthesis of furan-fused eight-membered heterocycles. Employing a one-pot procedure, easily accessible enynamides undergo cyclization to generate azadienes in situ, which subsequently participate in diastereoselective formal [4 + 4] cycloadditions with γ-methylene-δ-valerolactones. This strategy enables the rapid and efficient construction of a series of furan-fused azacyclooctanes with diverse substituents in good yields (63-97%) and a high level of diastereoselectivity (7:1 → 20:1 dr).

Catalyst-free inverse-electron-demand aza-Diels-Alder reaction of 4,4-dicyano-2-methylenebut-3-enoates and 1,3,5-triazinanes: access to polysubstituted tetrahydropyridines

An inverse-electron-demand aza-Diels-Alder reaction between 4,4-dicyano-2-methylenebut-3-enoates and 1,3,5-triazinanes under catalyst-free and additive-free conditions was developed, which provided a highly convenient and straightforward method to construct a series of polyfunctionalized tetrahydropyridines in high yields. This strategy features numerous advantages, including high efficiency, good functional group tolerance, broad substrate scope, and environmentally friendly conditions.

Enantioselective Synthesis of Ten-Membered Lactones via Palladium-Catalyzed [5 + 5] Annulation

Ten-membered lactones are the core units of many biologically active natural products but with a great synthetic challenge. Based on the principle of vinylogy, novel types of cyclic vinylogous anhydrides have been designed as five-carbon carbonyl synthons, further applied in [5 + 5] annulation with vinylethylene carbonates under chiral palladium catalysis. This strategy features excellent regioselectivity, mild conditions, and broad substrate scope, affording a range of spiro ten-membered lactones bearing oxindole and pyrrolidinone motif in excellent yield (up to 99%) with moderate to high enantioselectivity (up to 89% ee).

Base-Promoted Decarboxylative Annulation of Methyl 2-(2-Bromophenyl)acetates and Ynones to Access Benzoxepines

A simple and efficient base-mediated decarboxylative annulation of ynones with methyl 2-(2-bromophenyl)acetates has been developed. A broad range of benzoxepines were prepared with a broad substrate scope and high regioselectivity in moderate to excellent yields under transition-metal-free conditions. This method proceeds through a tandem [2 + 4] annulation, ring-opening decarboxylative reaction, and the intramolecular nucleophilic aromatic substitution reaction. Additionally, the key intermediates were successfully obtained and characterized unambiguously by single-crystal X-ray crystallography, which could favorably support a decarboxylative annulation mechanism. Furthermore, gram-scale reaction and synthetic applications for the further functionalization are also studied.

Palladium-Catalyzed [6+2] Double Allene Annulation for Benzazocines Synthesis

An efficient double allene protocol for the formation of benzazocines has been developed. The reaction constitutes a highly regioselective palladium-catalyzed formal [6+2] annulation of allenyl benzoxazinanones with terminal allenes forming the challenging 8-membered cycles. Decent yields and excellent regioselectivity have been observed under mild conditions with a remarkable Z-stereoselectivity for the exo-cyclic C=C bonds. The synthetic potentials of benzazocine products have been demonstrated.

Discovery of spirooxindole-derived small-molecule compounds as novel HDAC/MDM2 dual inhibitors and investigation of their anticancer activity

Simultaneous inhibition of more than one target is considered to be a novel strategy in cancer therapy. Owing to the importance of histone deacetylases (HDACs) and p53-murine double minute 2 (MDM2) interaction in tumor development and their synergistic effects, a series of MDM2/HDAC bifunctional small-molecule inhibitors were rationally designed and synthesized by incorporating an HDAC pharmacophore into spirooxindole skeletons. These compounds exhibited good inhibitory activities against both targets. In particular, compound 11b was demonstrated to be most potent for MDM2 and HDAC, reaching the enzyme inhibition of 68% and 79%, respectively. Compound 11b also showed efficient antiproliferative activity towards MCF-7 cells with better potency than the reference drug SAHA and Nutlin-3. Furthermore, western blot analysis revealed that compound 11b increased the expression of p53 and Ac-H4 in MCF-7 cells in a dose-dependent manner. Our results indicate that dual inhibition of HDAC and MDM2 may provide a novel and efficient strategy for the discovery of antitumor drug in the future.

A new type of δ-vinylvalerolactone for palladium-catalyzed cycloaddition: synthesis of nine-membered heterocycles

In this paper, a new type of δ-vinylvalerolactone was designed and synthesized, and used as a new precursor in Pd-catalyzed [6+3] cycloaddition with azomethine imines, leading to nine-membered 1,2-dinitrogen-containing heterocycles in 77-98% yields with >20 : 1 d.r. These nine-membered ring-fused products were further transformed into unusual tetracyclic bridged-ring compounds without loss of the diastereoselectivities.

High-order dipolar annulations with metal-containing reactive dipoles

Medium-sized heterocycles are widespread among a spectrum of structurally intriguing and biologically significant natural products and synthetic pharmaceuticals. Metal-catalyzed high-order dipolar annulations resembling reactions of metal-containing reactive dipoles with dipolarophiles constitute a highly efficient and flexible strategy for constructing medium-sized heterocycles. Mechanistically, these annulation reactions usually proceeding through stepwise pathways are different from the classic high-order pericyclic reactions that follow the Woodward-Hoffman rules. More significantly, asymmetric high-order dipolar annulations using chiral organometallic catalysts have been proven successful for constructing chiral medium-sized heterocycles with high enantio- and diastereoselectivity. This review highlights the impressive advances in this area and is focused on the reactivity, scope, mechanisms and applications of high-order dipolar annulation reactions.

Sulphur ylide-mediated cyclopropanation and subsequent spirocyclopropane rearrangement reactions

The efficient construction of cyclopropyl spiroindoline skeletons and the exploration of related follow-up synthetic transformations have elicited considerable interest amongst members of the chemistry community. Here, we describe a formal (2 + 1) annulation and three-component (1 + 1 + 1) cascade cyclisation via sulphur ylide cyclopropanation under mild conditions. The spiro-cyclopropyl iminoindoline moiety can be readily transformed into another medicinally interesting pyrrolo[3,4-c]quinoline framework through a novel rearrangement process.

Recent Advances in Decarboxylative Conversions of Cyclic Carbonates and Beyond

In recent years, functionalized cyclic organic carbonates have emerged as valuable building blocks for the construction of interesting and useful molecules upon decarboxylation under transition-metal catalysis. By employing suitable catalytic systems, the development of chemo-, regio-, stereo- and enantioselective methods for the synthesis of useful and interesting compounds has advanced greatly. On the basis of previous research on this topic, this short review highlights the synthetic potential of cyclic carbonates under transition-metal catalysis over the last two years.

1 Introduction

2 Transition-Metal-Catalyzed Decarboxylation of Vinyl Cyclic Carbonates

3 Zwitterionic Enolate Chemistry Based On Transition-Metal Catalysis

4 Decarboxylation of Alkynyl Cyclic Carbonates and Dioxazolones

5 Conclusions and Perspectives

Design, synthesis, and biological evaluation of tetrahydro-αcarbolines as Akt1 inhibitors that inhibit colorectal cancer cells proliferation

A series of densely functionalized THαCs were designed and synthesized as Akt1 inhibitors. Organocatalytic [3+3] annulation between indolin-2-imines 1 and nitroallylic acetates 2 provided rapid access to this pharmacologically interesting framework. In vitro kinase inhibitory abilities and cytotoxicity assays revealed that compound 3af was the most potent Akt1 inhibitor, and mechanistic study indicated that compound 3af suppressed the proliferation of colorectal cancer cells via inducing apoptosis and autophagy. Molecular docking suggested that the indole fragment of 3af was inserted into the hydrophobic pocket of Akt1 protein, and the H-bond between 3af and residue Lys179 also contributed to the stable binding. This article provides an efficient strategy to design and synthesize biologically important compounds as novel Akt1 inhibitors.

Kinetically Controllable Construction of Nine-Membered Carbocycles via Pd-Catalyzed Decarboxylative Cycloaddition

A kinetically controllable strategy toward the construction of otherwise challenging nine-membered carbocycles is reported. This Pd-catalyzed decarboxylative procedure utilizes vinyl methylene cyclic carbonates as the C5-dipole and allylidenemalononitriles as C4-building blocks. The protocol features user-friendly operations with controllable regioselectivity and generates CO₂ as the sole byproduct. The formation of synthetically valuable and thermodynamically favored seven-membered carbocycles was also investigated.

Construction of nine-membered N,N,O-heterocycles via Pd-catalyzed [6+3] dipolar cycloaddition

A new approach for the synthesis of 9-membered N,N,O-heterocycles by Pd-catalyzed [6+3] dipolar cycloaddition of N-iminoisoquinolinium ylides and 2-vinyl oxetanes has been developed.

Selective approach to N-substituted tertiary 2-pyridones

Commercially available 2-hydroxypyridines are converted into enantiomerically enriched allylic 2-pyridones with elusive N-substituted tertiary carbon by means of Pd-catalyzed allylic amination of vinyl cyclic carbonates.

Palladium-catalysed stereoselective [3 + 2] annulation of vinylethylene carbonates and tryptanthrin-based ketones

The first example of palladium-catalysed [3 + 2] annulation of VECs and ketones has been developed, allowing the efficient synthesis of indoloquinazolinones in generally excellent yields with good stereoselectivity.

Organocatalytic asymmetric synthesis of multifunctionalized α-carboline-spirooxindole hybrids that suppressed proliferation in colorectal cancer cells

An asymmetric organocatalytic cascade reaction has been reported for the rapid assembly of multifunctionalized α-carboline-spirooxindole hybrids, which suppressed proliferation in colorectal cancer cells.

Ferroptosis in Non-Small Cell Lung Cancer: Progression and Therapeutic Potential on It

As a main subtype of lung cancer, the current situation of non-small cell lung cancer (NSCLC) remains severe worldwide with a 19% survival rate at 5 years. As the conventional therapy approaches, such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy, gradually develop into therapy resistance, searching for a novel therapeutic strategy for NSCLC is urgent. Ferroptosis, an iron-dependent programmed necrosis, has now been widely considered as a key factor affecting the tumorigenesis and progression in various cancers. Focusing on its effect in NSCLC, in different situations, ferroptosis can be triggered or restrained. When ferroptosis was induced in NSCLC, it was available to inhibit the tumor progression both in vitro and in vivo. The dominating mechanism was due to a regulation of the classic ferroptosis-repressed GSH-dependent GPX4 signaling pathway instead of other fractional regulating signal axes that regulated ferroptosis via impacting on the ROS, cellular iron levels, etc. In terms of the prevention of ferroptosis in NSCLC, an GSH-independent mechanism was also discovered, interestingly exhibiting the same upstream as the GPX4 signaling. In addition, this review summarizes the progression of ferroptosis in NSCLC and elaborates their association and specific mechanisms through bioinformatics analysis with multiple experimental evidence from different cascades. Finally, this review also points out the possibility of ferroptosis working as a novel strategy for therapy resistance in NSCLC, emphasizing its therapeutic potential.

Asymmetric [4 + 3] Annulations for Constructing Divergent Oxepane Frameworks via Cooperative Tertiary Amine/Transition Metal Catalysis

We report asymmetric [4 + 3] annulations between isatin-derived Morita-Baylis-Hillman carbonates and two types of vinyl carbonates synergistically catalyzed by tertiary amines and transition metals, through chemoselective assemblies of in situ formed allylic ylides and metal-containing 1,4-dipoles. A range of oxepane frameworks are generally constructed in moderate to good yields with high stereocontrol. Moreover, all four diastereomers for the products bearing vicinal stereocenters are accessible by tuning tertiary amine and metal catalysts.

Biochanin A from Chinese Medicine: An Isoflavone with Diverse Pharmacological Properties

Biochanin A (BCA) is a dietary isoflavone, isolated from the leaves and stems of Trifolium pratense L and many other herbs of Chinese medicine. Recent findings indicated BCA as a promising drug candidate with diverse bioactive effects. On the purpose of evaluating the possibility of BCA in clinical application, this review is trying to provide a comprehensive summary of the pharmacological actions of BCA. The publications collected from PubMed, ScienceDirect, and Wiley databases were summarized for the last 10 years. Then, the potential therapeutic use of BCA on the treatment of various diseases was discussed according to its pharmacological properties, namely, anticancer, anti-inflammatory, anti-bacterial, anti-diabetic, and anti-obesity effects as well as neuroprotective, hepatoprotective, cardioprotective, and osteoprotective effects. BCA might mainly regulate the MAPK, PI3K, NRF2, and NF-kB pathways, respectively, to exert its bioactive effects. However, the limited definitive targets, poor biological availability, and insufficient safety evaluation might block the clinical application of BCA. This review may provide new insights for the development of BCA in the application of related diseases.

Generation of zwitterionic trifluoromethyl N-allylic ylides and their use in switchable divergent annulations

The previously unreported zwitterionic N-allylic ylide species from the corresponding Morita-Baylis-Hillman carbonates of trifluoromethyl ketones and acrylonitrile are generated under the catalysis of cinchona-derived tertiary amines, and subsequently participate in switchable asymmetric [3+2] or [4+1] annulations with 1-azadienes in chemo-, regio-, and stereodivergent manners via catalyst or substrate control. A diverse range of frameworks, having a trifluoromethylated all-carbon quaternary stereogenic centre or a tetrasubstituted alkene moiety, are generally constructed in good yields with excellent enantioselectivity.