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DFT calculations demonstrate that an isoacenofuran of any size possesses a smaller HOMO–LUMO gap than the corresponding acene bearing an isoelectronic π-system (i.e., the same total number of rings). Isoacenofurans show limited stability due in part to the highly reactive 1,3-carbons of the furan ring. Both 1,3-dimesitylisobenzofuran and 1,3-di(2’,4’,6’-triethylphenyl)isobenzofuran, each bearing sterically congesting ortho-alkyl groups on their phenyl substituents, have been synthesized and shown to adopt non-planar conformations with the ortho-alkyl groups located above and below the most reactive 1,3-carbons of the furan ring. These bulky substituents provide a strong measure of kinetic stabilization. Thus, 1,3-dimesitylisobenzofuran and 1,3-di(2’,4’,6’-triethylphenyl)isobenzofuran are significantly less reactive than 1,3-diphenylisobenzofuran toward the strong dienophiles DMAD and acrylonitrile. The insights gained here suggest that the synthesis of large, persistent, kinetically stabilized isoacenofurans with unusually small HOMO–LUMO gaps is achievable. As such, these molecules deserve increased attention as potential p-type organic semiconductors.

Herein, we disclosed the asymmetric construction of an oxa‐quaternary stereocenter via an intramolecular oxa‐Michael (IOM) reaction in β‐substituted ortho‐hydroxymethyl chalcone by the formation of 1,1‐disubstituted‐1,3‐dihydroisobenzofuran using cinchona alkaloid‐based chiral amino‐squaramide catalyst. Both the (E‐ and Z)‐β‐substituted ortho‐hydroxymethyl chalcone provide (S)‐ and (R)‐enantiomers of the 1,1‐disubstituted‐1,3‐dihydroisobenzofuran with excellent stereospecificity. In general, excellent yields (up to 95 %) and enantioselectivity (up to 98 % ee) were obtained. Furthermore, the resulting 1,1‐disubstituted isobenzofuran or phthalan was converted to corresponding chiral 3,3‐disubstituted phthalides without losing the enantioselectivity. This methodology provides the core moiety of the (S)‐citalopram drug. [ABSTRACT FROM AUTHOR]

Singlet fission (SF) has been proven to be an effective strategy to overcome the Shockley--Queisser limit of photovoltaics. However, the materials suitable for SF are relatively rare due to the strict requirements for the occurrence of this process. In the present study, we report the first preparation of two heteroatoms (O and S)-doped polycyclic aromatic hydrocarbons (PAHs) molecules with (β, β) connected furan/thiophene ring. The optical and physiochemical properties of both compounds are investigated by a variety of spectroscopies, including UV--vis absorption, photoluminescence and cyclic voltammetry. In addition, their ultrafast excited state dynamics are studied by femtosecond transient absorption. Experimental data showed that the singlet fission efficiency was improved by 2 times when replacing oxygen with sulfur atom, which could provide some guidelines in designing singlet fission materials with better efficiency. [ABSTRACT FROM AUTHOR]

c‐fused furan and their derivatives are widely used as essential components of agrochemicals, bioregulators, dyes, essential skin and hair oils, cosmetics, flavouring agents, photosensitizers in industry and also show a broad range of biological activity. To the best of our knowledge, as of yet, no review has been published that covers the entire synthetic pathway leading to the formation of just c‐fused or 3, 4‐fused furans. In this review, we outline the various pathways for bicyclic, tricyclic, and polycyclic c‐fused furans, along with their detailed mechanisms, concrete examples, and biological activity. We have focused particularly on the synthetic route to medicine, natural products, and their analogues, such as c‐fused furanoditerpenes isospongiadiol, radermachol, a potential folk medicine ingredient, furo[3,4]quinolin‐4(5H)‐ones core, an inhibitor of lymphoma, bhimamycin B, hibiscone‐c core moiety of antibiotic lactonamycin, and analogue of natural product furanether A/ furanether B. Previous approaches and recent methods are described including metal‐free, transition metal, bio‐catalyst, and multi‐substrate approaches with mechanisms. The review covers the literature for more than six decades and presents an overview of the synthesis of different c‐fused furans and their utility in various disciplines such as synthetic chemistry, medicinal chemistry, and drug discovery. [ABSTRACT FROM AUTHOR]

Described herein are the first total syntheses of (±)‐dracocephalone A (1) and (±)‐dracocequinones A (4) and B (5). The synthesis was initially envisioned as proceeding through an intramolecular isobenzofuran Diels–Alder reaction, a strategy that eventually evolved into a Lewis acid‐promoted spirocyclization. This highly diastereoselective transformation set the stage for trans‐decalin formation and a late‐stage Suárez oxidation that produced a [3.2.1] oxabicycle suited for conversion to 1. Brønsted acid‐mediated aromatization, followed by a series of carefully choreographed oxidations, allowed for rearrangement to a [2.2.2] oxabicycle poised for conversion to 4 and 5. [ABSTRACT FROM AUTHOR]

In this work, we describe the N‐iodosuccinimide‐mediated benzyl sp3 C−H oxidation of 2‐alkyl‐substituted benzamide derivatives. This Hofmann‐Löffler‐Freytag (HLF) type reaction involving intramolecular sp3 C−O bond formation differs from the construction of the C−N bond in the classic and modified HLF reactions. This reaction proceeded smoothly via 1,5‐hydrogen atom transfer of N‐centered radicals directly afforded by in situ N−I bond generation, providing iminoisobenzofuran derivatives in moderate to excellent yields with exclusive chemoselectivity. [ABSTRACT FROM AUTHOR]

DFT calculations demonstrate that an isoacenofuran of any size possesses a smaller HOMO-LUMO gap than the corresponding acene bearing an isoelectronic π-system (i.e., the same total number of rings). Isoacenofurans show limited stability due in part to the highly reactive 1,3-carbons of the furan ring. Both 1,3-dimesitylisobenzofuran and 1,3-di(2',4',6'-triethylphenyl)isobenzofuran, each bearing sterically congesting ortho -alkyl groups on their phenyl substituents, have been synthesized and shown to adopt non-planar conformations with the ortho -alkyl groups located above and below the most reactive 1,3-carbons of the furan ring. These bulky substituents provide a strong measure of kinetic stabilization. Thus, 1,3-dimesitylisobenzofuran and 1,3-di(2',4',6'-triethylphenyl)isobenzofuran are significantly less reactive than 1,3-diphenylisobenzofuran toward the strong dienophiles DMAD and acrylonitrile. The insights gained here suggest that the synthesis of large, persistent, kinetically stabilized isoacenofurans with unusually small HOMO-LUMO gaps is achievable. As such, these molecules deserve increased attention as potential p-type organic semiconductors., (Copyright © 2024, Liu and Miller.)

[Display omitted] • Two new compounds were isolated from cultures of the fungus Marasmius berteroi. • Indanone and isobenzofuran are the main metabolites of Marasmius berteroi. • Three compounds revealed better nematicidal activity than albendazole. Chemical investigation on the cultures of the fungus Marasmius berteroi , resulted in the isolation of 10 compounds including 2 new ones named (S)-3,7-dihydroxy-1-indanone (1) and (S)-3-hydroxy-4-methoxy-3-methyl isobenzofuran-1(3 H)-one (2). Their structures were determined based on NMR, HRESIMS and ECD spectra analysis. Compounds 5 - 6 , 10 revealed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 95 %, 85 %, and 75 % at 2.5 mg/mL, respectively. [ABSTRACT FROM AUTHOR]

We extend excited-state structural analysis to quantify the charge-resonance and multi-exciton character in wave functions of weakly interacting chromophores such as molecular dimers. The approach employs charge and spin cumulants which describe inter-fragment electronic correlations in molecular complexes. We introduce indexes corresponding to the weights of local, charge resonance, and biexciton (with different spin structure) configurations that can be computed for general wave functions thus allowing one to quantify the character of doubly excited states. The utility of the approach is illustrated by applications to several small dimers, e.g., He-H2, (H2)2, and (C2H4)2, using full and restricted configuration interaction schemes. In addition, we present calculations for several systems relevant to singlet fission, such as tetracene, 1,6-diphenyl-1,3,5-hexatriene, and 1,3- diphenylisobenzofuran dimers. [ABSTRACT FROM AUTHOR]

In this paper, we present a Lewis-acid-promoted reaction of 2-benzoylbenzaldehyde and trialkenyl phosphites, which resulted in the formation of polycyclic phosphonates. The reaction proceeded via nucleophilic attack of trialkenyl phosphite on the carbonyl carbon of 2-benzoylbenzaldehyde. The subsequent intramolecular Diels-Alder reaction led to the formation of the cyclic phosphonate.

Ajudazol B is a polyketide secondary metabolite, isolated from the myxobacterium Chondromyces crocatus, that exhibits potent biological activity. Herein, we report a convergent total synthesis of 8‐epi‐(–)‐ajudazol B. The key step is a regio‐selective alkylation and oxidative rearrangement of a reactive isobenzofuran intermediate that generates the isochromanone core. This approach provides a fast and efficient method to synthesise analogues of ajudazol B from simple aldehydes, allowing assessment of structure‐activity relationships. The antifungal activity of 8‐epi‐(–)‐ajudazol B as well as that of related analogues has been assessed using Botrytis cinerea. The results indicate that the isochromanone unit is key for antifungal activity. [ABSTRACT FROM AUTHOR]

Aim: Amyloid-β (Aβ) accumulation, accelerated by traumatic brain injury (TBI), may play a crucial role in neurodegeneration in chronic-stage TBI. The injury type could influence Aβ dynamics because of TBI's complex, heterogeneous nature. We, therefore, investigated spatial patterns of amyloid deposition according to injury type after TBI using 5-(5-(2-(2-(2-[F]-fluoroethoxy)ethoxy)ethoxy)benzofuran-2-yl)-N-methylpyridin-2-amine (18F-FPYBF-2) positron emission tomography (PET). Methods: Altogether, 20 patients with chronic TBI [12 with focal injury, 8 with diffuse axonal injury (DAI)] underwent 18F-FPYBF-2 PET, structural magnetic resonance imaging (MRI), and neuropsychological examination. Additionally, 50 healthy controls underwent either 18F-FPYBF-2 PET (n=30) or structural MRI (n=20). Results: Standardized uptake value ratio (SUVR) on PET images and regional brain volumes were measured in four cortical (frontal, parietal, occipital, temporal) and subcortical (combined caudate, putamen, pallidum, thalamus) regions. Patients with DAI showed significantly increased (compared with controls) SUVR in occipital and temporal cortices and decreased brain volume in occipital cortex (corrected p < 0.05). Although patients with focal injury showed decreased SUVR in all regions except occipital cortex, there were no significant differences (compared with controls) in the SUVR in any regions. There were no significant correlations between increased SUVR and neuropsychological impairments in patients with DAI. Conclusion: Varying spatial patterns of amyloid deposition suggest amyloid pathology diversity depending on the injury type in chronic-TBI patients. [ABSTRACT FROM AUTHOR]

The synthesis, isolation and characterization of isobenzofuran are described in this publication. Isobenzofuran is of general interest in synthetic and physical organic chemistry because it is one of the most reactive dienes known. A number of synthetic pathways have been published which all suffer from disadvantages such as low yields and difficult purification. We present a synthetic pathway to prepare isobenzofuran in laboratory scale with high yields, from affordable, commercially available starting materials.

Phthalocyanines (Pcs) 5a‐Mg, 5b‐Mg, 6a‐Mg, and 6b‐Mg with eight alkoxy groups at α‐positions and 2‐ or 4‐pyridylthio groups at the β‐positions, were prepared from 3,6‐dialkoxy‐4,5‐dipyridylthiophthalonitriles. Magnesium complexes 5a‐Mg, 5b‐Mg, and 6a‐Mg were treated with trifluoroacetic acid to produce free‐base compounds 5a‐2H, 5b‐2H, and 6a‐2H. In the UV/Vis spectra, Q‐band absorption of Mg and free‐base Pcs appeared near 760 nm and 780 nm, respectively, in chloroform and 745 nm and 760 nm, respectively, in methanol. Emission spectra of these Pcs showed small Stokes shifts in chloroform and methanol. Reactions of 5a‐Mg, 5b‐Mg, and 5b‐2H with methyl iodide produced the corresponding Pcs 7a‐Mg, 7b‐Mg, and 7b‐2H with methyl pyridinium groups, respectively. After methylation of the pyridine nitrogen, the Pcs were moderately soluble in water but had little solubility in chloroform. The UV/Vis and emission spectra of methylated Pcs 7a‐Mg, 7b‐Mg, and 7b‐2H were obtained in methanol and water. Photobleaching of diphenylisobenzofuran (DPBF) was examined in methanol in the presence of Pcs 7b‐Mg and 7b‐2H, and was monitored by UV/Vis spectroscopy. [ABSTRACT FROM AUTHOR]

The kinetics of (3+2) cycloaddition reactions of 18 different donor–acceptor cyclopropanes with the same aldehyde were studied by in situ NMR spectroscopy. Increasing the electron density of the donor residue accelerates the reaction by a factor of up to 50 compared to the standard system (donor group=phenyl), whereas electron‐withdrawing substituents slow down the reaction by a factor up to 660. This behavior is in agreement with the Hammett substituent parameter σ. The obtained rate constants from the (3+2) cycloadditions correlate well with data from additionally studied (3+n) cycloadditions with a nitrone (n=3) and an isobenzofuran (n=4). A comparison of the kinetic data with the bond lengths in the cyclopropane (obtained by X‐ray diffraction and computation), or the 1H and 13C NMR shifts, revealed no correlation. However, the computed relaxed force constants of donor–acceptor cyclopropanes proved to be a good indicator for the reactivity of the three‐membered ring. Who is faster? The reactivity of donor–acceptor cyclopropanes was investigated in (3+n) cycloaddition reactions with an aldehyde, a nitrone, and an isobenzofuran by NMR and in operando IR spectroscopy. The obtained reaction rates were compared with the structural and electronic properties of the donor–acceptor cyclopropanes. [ABSTRACT FROM AUTHOR]

Graphical abstract R N H 2 : 12 examples including bifunctional reagents. *R 2 N H: only cyclic sec -amines, and no reactions for the corresponding acyclic counterpart. Highlights • Facile construction of CF 3 -containing γ-lactams starting from primary amines. • Further cyclization from the product using 2-aminoethanol. • Net substitution reactions from cyclic secondary amines. Abstract Unprecedented isobenzofuran-1-ones (phthalides) with CF 3 and ethoxy groups both at the 3-position were readily synthesized from the corresponding aromatic 1,2-diesters and reacted with a variety of primary amines to find out convenient conversion to the corresponding γ-lactams, while secondary amines behaved in a totally different manner to affect the net substitution reactions for the EtO moiety, where characteristics of the strongly electron-withdrawing CF 3 group was considered to play a significantly important role. [ABSTRACT FROM AUTHOR]

We have demonstrated that reactions of aromatic 1,2‐diesters and the Ruppert–Prakash reagent (TMSCF3) afforded hitherto unknown phthalides 1 with both trifluoromethyl (CF3) and alkoxy groups at the 3 position, and their unique transformation was also investigated in detail to attain construction of a variety of very rare types of compounds, such as 1,3‐dihydroisobenzofurans 8 as well as indanones 9 with a CF3 moiety, whose behavior was completely different from the structurally similar compound 2a. A variety of transformation of unprecedented phthalides readily formed by the reaction of TMSCF3 and aromatic 1,2‐diesters resulted in obtaining different types of CF3‐containing compounds, which were almost inaccessible by previously developed methods. [ABSTRACT FROM AUTHOR]

An efficient generation method of didehydroisobenzofuran, a new heteroaryne species, was developed by bromine/lithium exchange of the dibromoisobenzofuran. The reactive intermediate, thus generated, was trapped by appropriate arynophile to give the [2+2], [2+3], and [2+4] cycloadducts, respectively. Moreover, the reaction could be applied to the syntheses of isoanthracenofurans (anthra[2,3‐c]furans), a new class of heteroacenes, with isoelectoronic structure to the corresponding acenoheteroles (anthra[2,3‐b]furans). An efficient generation method of didehydroisobenzofuran, a new heteroaryne species, was developed by bromine/lithium exchange of the dibromoisobenzofuran. The reactive intermediate, thus generated, was trapped by arynophiles to give various cycloadducts, one of which could be converted to isoanthracenofurans, a new class of heteroacenes, possessing unique physical properties (see scheme). [ABSTRACT FROM AUTHOR]

[Display omitted] • Commercial montmorillonite K-30 as a catalyst for 3-carene isomerization to 2-carene. • Increase of 2-carene yield with a decrease in the Lewis to Brønsted acid sites ratio. • Commercial K-10 clay as a catalyst of synthesis of chiral isobenzofurans from 2-carene containing reaction mixture. • Increase of the isobenzofurans yield using the 2-carene containing mixture as compared to 2-carene per se. Isomerization of 3-carene to the reaction mixture, containing 2-carene and its further utilization in the synthesis of chiral isobenzofurans, was investigated in the presence of acid-modified clays at 140 °C. The catalysts were characterized by XRF, FTIR with pyridine and nitrogen adsorption. Quantification of the effect of the type and concentration of acid sites in different clays comprising commercial montmorillonite and natural illite on the yield of 2-carene as well as by-products was obtained for the first time. It was established that selectivity to 2-carene decreased with an increase of the Lewis to Brønsted acid sites ratio. The largest amount of 2-carene in the mixture (15.0 wt.%) with the highest ratio of 2-carene to menthadienes (0.63) was observed at 50% 3-carene conversion over a commercial montmorillonite K-30 clay, which has a moderate (100 μmol/g) acidity. It was demonstrated for the first time that the mixture containing 2-carene can be effectively used as a starting material in the reaction with vanillin resulting in chiral isobenzofurans. The products obtained in this reaction exhibit neuroprotective activity in an animal Parkinson's disease model. It was established that isobenzofurans yield decreased with an increase in the Lewis to Brønsted acid sites ratio. The largest yield of these products was obtained in the presence of a commercial K-10 clay (59.8%), which is higher than using 2-carene per se. Catalytic synthesis of isobenzofurans based on a readily available monoterpene 3-carene instead of expensive 2-carene was thus developed. [ABSTRACT FROM AUTHOR]

Successive treatment of potassium 1,1,3,3-tetracyano-2-(2-(methoxycarbonyl)benzoyl)prop-2-enide with concentrated sulfuric acid and water gave 2-(5′-amino-4′-cyano-3-oxo-3H,3′H-spiro[[2]benzofuran-1,2′-furan]-3′-ylidene)propanedinitrile. The reaction of the title compound with sodium hydroxide, followed by neutralization with sulfuric acid afforded 4′-amino-3,3′,6′-trioxo-2′,3′,5′,6′-tetrahydro-3H-spiro[[2]benzofuran-1,1′-pyrrolo[3,4-c]pyridine]-7′-carbonitrile. [ABSTRACT FROM AUTHOR]

Successive [2+4] cycloadditions of arynes and isobenzofurans by site-selective halogen-lithium exchange of 1,2-dihaloarenes were developed, allowing the rapid construction of polycyclic compounds which serve as a useful synthetic intermediates for the preparation of various polyacene derivatives.

Abstract Aims Previous studies performed by our research group indicated that cytosporone analogues are capable of prevent or repair DNA damages. This work presents the evaluation of the activity of AMS35AA for metastatic murine melanoma cells (B16F10) in experimental model in vitro and, in pre-clinic assay of metastatic melanoma in vivo, using mice lineage C57BL/6. Main methods In vitro assays were performed: MTT and comet assay, flow cytometry evaluation, gene expression assay by RT-PCR, qualitative evaluation of cell death using B16F10 cells. In vivo assays: micronucleus and comet assay, splenic phagocytosis, melanoma murine model and histopathological analysis, using mice lineage C57BL/6 (n = 20). Key findings In vitro results performed by MTT assay showed that AMS35AA is cytotoxic for B16F10 cells (p < 0.05). Based on comet assay the genotoxicity of the IC 50 was determined (95.83 μg/mL) (p < 0.05). These data were corroborated by flow cytometry analysis after the treatment with AMS35AA, which indicates the cellular death by apoptosis (p < 0.05) and increasing of ATR, p53, p21 and GADD45 gene expressions verified using RT-PCR. With respect to in vivo results, it was observed that AMS35AA did not show genotoxic activity. Data of tumor volume ex vivo indicate reduction of tumor for the treated animals with AMS35AA up to 15.84×, which is superior to Dacarbazina (50 mg/Kg, p.c.; i.p.). Significance In summary, the study showed that AMS35AA reveals relevant results regarding to cytotoxicity of B16F10 murine melanoma cells, inducing death by apoptosis via mitochondrial and/or mediated by DNA damages. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

In the present work, the 2‐benzoxazinonyl benzoic acid (BBA) could be isomerized to the stereogenic spiro products (SBI) via ultrasonic and basic reaction conditions. The spiro compounds (SBI) have both electrophilic and nucleophilic centers. A series of nitrogen nucleophiles such as hydrazine hydrate, glycine, 2‐aminopyridine, 2‐picolinylamine, 4‐anisidine, 4‐aminoacetophenone and carbon electrophiles such as oxiranylmethylchloride, ethylchloroacetate, chloroacetylchloride, Mannich reagents, for example, formaldehyde with piperidine or morpholine can be treated with 2‐benzoxazine‐2‐yl benzoic acid (BBA) via multicomponent reaction. The basicity of previous nucleophiles can be controlled on the course of reaction of 2‐benzoxazinonyl benzoic acid. The chemical structure of the synthesized compounds can be confirmed by microanalytical, spectral data and optimized by quantum chemical parameters. [ABSTRACT FROM AUTHOR]

Abstract: Annulative π‐extension of benzothiophene S,S‐dioxide analogues has been achieved via Diels‐Alder reaction of symmetrical 1,3‐diaryl/heteroarylbenzo[c]furans with benzothiophene S,S‐dioxides in toluene at reflux followed by PTSA‐mediated deoxygenation reaction. Employing this one‐pot π‐extension protocol, synthesis of complex seven and nine member heteroacenes was also achieved. [ABSTRACT FROM AUTHOR]

Alkyne-based regioselective functionalization is an important transformation method for the synthesis of a wide variety of organic products. In this work, a regioselective TBAI-mediated oxidative 5- exo-dig iodo-oxy cyclization of 2-alkynylbenzamide is used for the synthesis of various isobenzofuran derivatives with excellent functional group tolerance and high reaction efficiency. We hypothesized that using water in a mixed solvent could change the reaction pathway and realize a high reaction regioselectivity. Furthermore, the application of the developed procedure was demonstrated by the synthesis of phthalazin-1(2 H )-one and aryl-substituted isobenzofurans. [ABSTRACT FROM AUTHOR]

Diels-Alder reaction of 1,3-diarylbenzo[c]furan/cyclopentadienone with TTF followed by triflic acid mediated cleavage of the resulting adducts led to the formation of the respective 1,4-diaryl substituted naphthalenes, fluoranthenes, and fluorenones. The photophysical properties of representative diaryl-substituted hydrocarbons are also reported. [ABSTRACT FROM AUTHOR]

The substituent and solvent effects on solvatochromism in 3-[(4-substituted) phenylamino]isobenzofuran-1(3H)-ones were studied using experimental and theoretical methodologies. The effect of specific and non-specific solvent–solute interactions on the shifts of UV–Vis absorption maxima were evaluated using the Kamlet–Taft and Catalán solvent parameter sets. The experimental results were studied by density functional theory (DT) and time-dependent density functional theory (TD-DFT). The HOMO/LUMO energies (EHOMO/ELUMO) and energy gap (Egap) values, as well as the mechanism of electronic excitations and the changes in the electron density distribution in both ground and excited states of the investigated molecules were studied by calculation in the gas phase. The electronic excitations were calculated by the TD-DFT method in the solvent methanol. It was found that both substituents and solvents influence the degree of π-electron conjugation of the synthesized molecules and affect the intramolecular charge transfer character. [ABSTRACT FROM AUTHOR]

Oxidation of some derivatives of 4b,9b-dihydroxyindeno[1,2- b]benzofuran-10-one have been investigated in detail using lead(IV) acetate in acetic acid under reflux conditions and periodic acid in aqueous ethanol at room temperature. We realized that during the first 5-15 minutes of the oxidation reactions in lead(IV) acetate/acetic acid system, 3 H,3' H-spiro[benzofuran-2,1′-isobenzofuran]-3,3′-dione derivatives have been synthesized chemo selectively, while, if the reaction mixtures stirred for additional 3 hours, the main products would be 2-(2-(Methoxycarbonyl)-3-oxo-2,3-dihydrobenzofuran-2-yl)benzoic acids. Moreover, room temperature oxidation of 4b,9b-dihydroxyindeno[1,2- b]benzofuran-10-ones by periodic acid (H5IO6), leads to the formation of 3 H,3' H-spiro[benzofuran-2,1′-isobenzofuran]-3,3′-dione derivatives in good to excellent yields. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed copper-free Sonogashira coupling of 2- bromocarbonyls is presented. This method afforded the 2-alkynylaryl carbonyls, useful synthons for the accomplishment of many carbocyclic and heterocyclic motifs. Significantly, the strategy was extended to the one-pot synthesis of isobenzofurans via reduction followed by intramolecular 5-exo-dig cyclization. [ABSTRACT FROM AUTHOR]

Abstract: Diels‐Alder reaction of 1,3‐diarylisobenzofurans with cyclopenten‐1‐one as well as 2‐cyclohexen‐1‐one in the presence of TMSOTf in DCM at 0 °C furnished 4,5‐diarylbenzo[e]inden‐1‐ones and 6,7‐diarylbenzo[f]α‐tetralones. The benzo[e]inden‐1‐ones/benzo[f]α‐tetralones upon Fischer indolization led to the formation of indeno[b]indoles and dihydronaphtho[a]carbazoles, respectively. [ABSTRACT FROM AUTHOR]

Three-directional annulations of isobenzofuran trimer equivalent are developed. Importantly, the successive cycloadditions could be controlled under suitable conditions, selectively affording the dual or triple cycloadduct, which leads to the alternative preparation of the symmetrical and unsymmetrical star-shaped polycyclic aromatic ketones. ¹H NMR analysis of the star-shaped aromatic ketone indicated the π-π interactions through the aggregation in solution. [ABSTRACT FROM AUTHOR]

Reactions of furyl(diethoxyphosphoryl)acetic aldehyde containing ester or cyano group in the furan ring with ethoxycarbonylmethylenetriphenylphosphorane has been shown to afford alkyl E-4-(furyl)-4-(diethoxyphosphoryl)but-3(2)-enoates. When treated with potassium tert-butoxide the mixture of alkyl E-4-(3-ethoxycarbonylfur-2-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate gives a potassium salt of CHacid. Its acidifying results in a mixture of starting compounds with a larger amount of -but-3-enoate. Under analogous conditions the mixture of alkyl E-4-(2-ethoxycarbonylfur-3-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate undergoes cyclization to a phosphorylated derivative of alkyl 7-hydroxybenzofuran-6-carboxylate. The cyclization of the mixture of alkyl E-4-(4-ethoxycarbonylfur-3-yl)-4-(diethoxyphosphoryl)but-2-enoate and -but-3-enoate gives analogous derivative of isobenzofuran. [ABSTRACT FROM AUTHOR]

The title structure, (3R*, 1'S*, 3'R*)-3-(1'-tertbutylamino- 1'H,3'H-benzo[c]furan-3'-yl)-2-tert-butyl-2,3- dihydro-1H-benzo[c]pyrrol-1-one has been determined at 290 and 150 K by single-crystal X-ray diffraction. The structure comprises two symmetry independent molecules with very similar conformations which differ mostly by orientations of the tert-butyl groups, situated at the periphery of these molecules. The molecules are composed of two parts, the cores of which are isoindolinone and isobenzofuran rings being bound by C-C bonds. The planarities of the pyrrolone and furan rings are compared with the known structures retrieved from the Cambridge Crystal Structure Database. It transpires in the title molecules, the planarity of the carbonyl-substituted pyrrole rings is exceptionally distorted in contrast to the furan rings. This fact is just the opposite of the tendency inferred from the Cambridge Crystal Structure Database. The reason may be the influence of the voluminous tertbutyl group which is attached to the nitrogen of the pyrrole group, as well as short centroid-centroid distances between the carbonyl-substituted pyrrole and furan rings. Cohesion forces between the molecules and their parts are provided by weak interactions only: The packing suggests C-H···O, π-π-electron ring interactions, N-H···π-electron ring as well as C-H···π-electron ring interactions. The structure determination of the title compound, the product of the reaction of o-phthalaldehyde with tert-butylamine, has provided indication about the mechanism of a chemical reaction which resulted in the formation of the title molecule. [ABSTRACT FROM AUTHOR]

1-Sulfonyl-1,2,3-triazoles undergo inter- and intramolecular 1,3-OH insertion with rhodium(II)-azavinyl carbenoid intermediates upon treatment with a rhodium(II) catalyst. Products of this transformation contain a synthetically versatile N -(2-alkoxyvinyl)sulfonamide, enabling divergent reactivity toward several N -protected phenethylamine derivatives under various conditions. Notably, products with a phthalan framework can be accessed directly from 4-aryl-1-sulfonyl-1,2,3-triazoles bearing a pendant alcohol. [ABSTRACT FROM AUTHOR]

This article describes an efficient approach for the synthesis of 5-amino-3-methyl-7-aryl-1,3-dihydroisobenzofuran-4,6-dicarbonitrile derivatives from the reaction of aromatic aldehyde, 2-methyltetrahydrofuran-3-one, and malononitrile under mild conditions. This is a simple and facile process to structure this important heterocyclic compounds. The other advantages of this approach are rapid reaction rate, high yield, and simple procedure. This article provided a good method for the synthesis of 1,3-dihydroisobenzofuran derivatives. [ABSTRACT FROM AUTHOR]

Two new isobenzofurans, 1-(3-hydroxypropanoyl)-2-methoxy-isobenzofuran-1(3H)-one ( 1) and 2-methoxy-1-prenyl-isobenzofuran-1(3H)-one ( 2), were isolated from the leaves of Yunnan local sun-cured tobacco. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their cytotoxicity. The results revealed that compound 1 exhibited cytotoxicity for NB4, A549, SHSY5Y, PC3, and MCF7 cells with IC values of 2.8, 5.4, 6.9, 3.8, and 4.9 μM, and compound 2 exhibited cytotoxicity for NB4, A549, SHSY5Y, PC3, and MCF7 cells with IC values of 6.6, 7.8, 9.4, 7.0, and 9.2 μM, respectively. [ABSTRACT FROM AUTHOR]

Singlet fission (SF) has been proven to be an effective strategy to overcome the Shockley-Queisser limit of photovoltaics. However, the materials suitable for SF are relatively rare due to the strict requirements for the occurrence of this process. In the present study, we report the first preparation of two heteroatoms (O and S)-doped polycyclic aromatic hydrocarbons (PAHs) molecules with (β, β) connected furan/thiophene ring. The optical and physiochemical properties of both compounds are investigated by a variety of spectroscopies, including UV-vis absorption, photoluminescence and cyclic voltammetry. In addition, their ultrafast excited state dynamics are studied by femtosecond transient absorption. Experimental data showed that the singlet fission efficiency was improved by 2 times when replacing oxygen with sulfur atom, which could provide some guidelines in designing singlet fission materials with better efficiency., (© 2023 Wiley-VCH GmbH.)

The polycyclic compounds, especially the dioxa-cages, have attracted considerable attention in recent years. In our work, a series of 9 β-substituted 3-oxo-4,11-dioxatetracyclo[5.2.1.15,8.02,6]undecane compounds were unexpectedly isolated during bromination, chlorination and epoxidation reactions of the 3-hydroxy-3a,4,7,7a-tetrahydro-4,7-methanoisobenzofuran-1(3 H)-one. After careful analysis of the NMR data, the chemical shifts of the isolated and the expected products were predicted by theoretical calculations using density functional theory and gauge including atomic orbitals. The best correlation between calculated and experimental data was evaluated by comparing mean absolute errors and applying DP4 probability methodology. Results from both approaches indicated a correct structural elucidation. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Herein we demonstrate a gold-catalyzed regio- and stereo-selective cycloisomerization of bis(o-alkynyl benzyl alcohols). By this protocol, the synthesis of dihydroisobenzofuran derivatives can be achieved in good yields. The reaction features a continuous alkyne/alkene-directed 5-exo-dig cyclization and a Prins-type cyclization for the formation of three cycles. [ABSTRACT FROM AUTHOR]

Two novel fluorescence “turn-on” cyanide probes based on the 1,3-dihydroisobenzofuran skeleton have been designed and synthesized: a terpyridyl-Cu 2+ ensemble sensed CN − in THF-H 2 O (1:1, v/v), and a dicyanovinyl-containing compound sensed CN − in CH 2 Cl 2 and THF. Titration of CN − with terpyridine-Cu 2+ complex caused a displacement reaction that turned on the fluorescence of A-Cu 2+ at 605 nm. The detection limit of A-Cu 2+ for CN − was calculated to be 3.15 × 10 −6 M. In the presence of CN − , the dicyanovinyl-bearing probe underwent a nucleophilic addition, showing 85-fold enhancement of fluorescence, with a detection limit of 5.39 × 10 −8 M. Our results demonstrate that these two strategies for designing a fluorophore skeleton based on the 1,3-dihydroisobenzofuran lead to highly selective “turn-on” probes for CN − . [ABSTRACT FROM AUTHOR]

Reaction of 1,3-disubstituted isobenzofurans (IBFs) with selenium dioxide in tetrahydrofuran (THF) at room temperature led to the formation of 1,2-diaroyl/(heteroaroyl)benzenes in good to excellent yields. [ABSTRACT FROM PUBLISHER]

No abstract is available for this article. [ABSTRACT FROM AUTHOR]