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Transition metal‐catalyzed carbonylation functionalization reaction of alkenes is an attractive research area in modern organic chemistry. However, there have been very few reports on silver‐catalyzed reactions in carbonylation reactions. Herein we developed a silver‐catalyzed carbamoylation and carbonylative cyclization of alkenes with oxamic acids to obtain 2‐acetylamino‐1‐tetralone derivatives. Various desired cyclized products were formed in moderate to good yields through radical intermediates. [ABSTRACT FROM AUTHOR]

This document provides information on the synthesis of the dopamine agonist Rotigotine, which is used to treat Parkinson's disease and restless leg syndrome. The authors discuss different synthetic approaches and successfully synthesized Rotigotine using reductive amination with a high yield. The document also includes information on the synthesis and characterization of three compounds related to Rotigotine, along with their spectral data. Additionally, it provides details on the synthesis and chiral separation of (±)-Rotigotine, including its chemical structure, physical properties, and analytical data. The authors acknowledge Chemveda Life Sciences for their assistance in the separation process. [Extracted from the article]

New chiral phosphine‐amine‐ether (PNO) ligands of the general formula Ph2PCH(R1)(CH2)nCH(R1)N(R2)CH(R3)CH2OMe, where R1, R2, and R3 = H or Me, n = 0 or 1, and their ruthenium complexes of the type [RuCl2(PPh3)(PNO)] have been synthesized. The coordination compounds were characterized by 1D and 2D NMR spectroscopy, modeled by DFT calculations, and in one case analyzed by X‐ray crystallography. The combined spectroscopic and theoretical investigations revealed that the relative configuration of the stereogenic elements in the P–N and N–O backbone represents a crucial factor in determining the conformation of the pincer‐type chelates and may also affect the configuration of the coordinated stereogenic nitrogen in the NH subunit, an essential element of stereochemical communication in outer sphere bifunctional catalysis. The new complexes were applied in the asymmetric hydrogenation of fused ring bicyclic ketones (i.e., 1‐tetralone and 4‐chromanone derivatives), a challenging substrate class, where enantioselectivities up to 97% could be obtained. Based on the spectroscopic and theoretical studies and catalytic experiments, structural features affecting the stereochemistry of the coordination could be identified and a qualitative enantioinduction model has been proposed. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C12H11F3O2, was elucidated by low-temperature single-crystal X-ray diffraction. The enantiopure compound crystallizes in the Sohncke space group P21 and features one molecule in the asymmetric unit. The structure displays intermolecular O—H...O hydrogen bonding, which links the molecules into infinite chains propagating parallel to [010]. The absolute configuration was established from anomalous dispersion.

The reduction of polyfluorinated benzocycloalken-1-ones, perfluoro-2,3-dihydrobenzofuran-3-one, and perfluorinated diaryl and alkyl aryl ketones with lithium tetrahydridoborate in diethyl ether gave the corre-sponding alcohols. The reduction of perfluorinated 2-methyl- and 2-hydroxy-2-phenylbenzocyclobutenones was accompanied by opening of the four-membered ring with the formation of (perfluoro-2-vinylphenyl)-methanol and [2-(hydroxymethyl)tetrafluorophenyl](pentafluorophenyl)methanol, respectively. Polyfluorinated benzocycloalkenediols were obtained in the reduction of dicarbonyl derivatives of perfluorinated benzocyclo-butene, indan, and tetralin. [ABSTRACT FROM AUTHOR]

The reduction of polyfluorinated benzocycloalken-1-ones, perfluoro-2,3-dihydrobenzofuran-3-one, and perfluorinated diaryl and alkyl aryl ketones with lithium tetrahydridoborate in diethyl ether gave the corre-sponding alcohols. The reduction of perfluorinated 2-methyl- and 2-hydroxy-2-phenylbenzocyclobutenones was accompanied by opening of the four-membered ring with the formation of (perfluoro-2-vinylphenyl)-methanol and [2-(hydroxymethyl)tetrafluorophenyl](pentafluorophenyl)methanol, respectively. Polyfluorinated benzocycloalkenediols were obtained in the reduction of dicarbonyl derivatives of perfluorinated benzocyclo-butene, indan, and tetralin. [ABSTRACT FROM AUTHOR]

A rapid and facile method of accessing 4‐phenyl‐β‐keto‐α‐tetralones is reported. The key homo‐Nazarov cyclization was achieved via treatment of the preceding phenylcyclopropane with TiCl4 at below ambient temperatures. In contrast to previous work, which was limited to electron‐rich substrates, the present transformations proceeded without heating and were applicable to an electronically broad range of substrates. Furthermore, a mechanistically novel reaction afforded an unexpected γ‐diarylketone as well as a rearranged regioisomer of the expected α‐tetralone. [ABSTRACT FROM AUTHOR]

Phytochemical investigation and chromatographic separation of extracts from the aerial parts of Dianella ensifolia (L.) DC. (synonym Dianella nemorosa Lam. Ex. Schiler f.) led to the isolation of 10 compounds, the structures of which were determined by HR-ESI-MS and 1 D- and 2 D-NMR spectroscopies, and by comparisons with published studies. Among the isolated compounds were three flavans, a biflavan, a biflavone, a tetralone, a naphthalen glycoside, an aromatic compound, and two steroids. Six of these were known chemicals, while three were identified as new compounds: 7-acetyl-4R,8-dihydroxy-6-methyl-1-tetralone, 2(S),2′,4′-dihydroxy-7-methoxyflavan, and diaensi-biflavan. 2(S),7,4'-dimethoxy flavan was obtained for the first time as a natural product. [ABSTRACT FROM AUTHOR]

The C−H functionalization of benzo‐fused cycloalkanones represents a synthetic challenge, since such scaffolds display different activation sites, at sp2 and sp3 carbons, a bicyclic structure, and various sizes of the cycloalkanone ring. Anticipating the outcome of C−H functionalization and the impact of the presence and size of the cycloalkanone ring would help to foresee synthetic routes to more complex molecular architectures. The mechanism of C−H arylation was studied using DFT calculations for tetralone, benzosuberone, and indanone and compared to acetophenone. Comparison of energetic profiles allowed identifying key steps of the process. Analysis of the topology of key intermediates allowed correlating the deformation of palladacycles to the potential reactivity of the benzo‐fused cycloalkanone family members. The experimental results were in full agreement with the trend provided by the theoretical study. A wide panel of diversely substituted benzo‐fused cycloalkanones has been successfully obtained using optimized conditions. Moreover, an approach towards polycyclic molecules has been illustrated featuring a C−H arylation and a second step taking advantage of the remaining ketone fragment and its ability to undergo diverse transformations leading to alternative pathways to more complex molecular architectures [ABSTRACT FROM AUTHOR]

Juglonols A−C (1−3), three new juglone derivatives possessing a hydroxyethyl side chain, were isolated from an organic extract of the immature exocarps of Juglans mandshurica together with five known tetralones (4–8). Their structures were elucidated by extensive spectroscopic analyses and comparison with literature data. The new juglone derivatives exhibited inhibitory activities towards a panel of bacteria and fungi, as well as cancer cell lines. In contrast, the known tetralone homologues (4−8) appeared to be much less efficacy. [ABSTRACT FROM AUTHOR]

Various enamines were synthesized by the reaction of 2-propargyl-α-tetralone with amines in the benzene media. The triple bond of the propargyl group in the side chain of the synthesized enamines is activated by the BF3•OEt2 catalyst to make nucleophilic addition of amines to the triple bond easier. An intermediate is obtained as a result of cyclization. In the course of the subsequent reaction, the intermediate is isomerized to form new derivatives of 4,5-dihydro-1H-benzo[g] indole. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesis of amino acid conjugates of 3-(1-chloro-3,4-dihydronaphthalen-2-yl) acrylic acid. • Screening for NorA inhibitors against Staphylococcus aureus. • The potent inhibitors displayed MEC of 1.56 μg/mL against NorA overexpressing strain SA-1199B. • Mechanism for NorA specificity elucidated by ethidium bromide efflux. Abstract Inhibitors for NorA efflux pump of Staphylococcus aureus have attracted the attention of many researchers towards the discovery and development of novel efflux pump inhibitors (EPIs). In an attempt to find specific potent inhibitors of NorA efflux pump of S. aureus , a total of 15 amino acid conjugates of 3-(1-chloro-3,4-dihydronaphthalen-2-yl)acrylic acid (4 – 18) were synthesized using a simple convenient synthetic approach and bioevaluated against NorA efflux pump. Two compounds 7 and 8 (each having MEC of 1.56 µg/mL) were found to restore the activity of ciprofloxacin through reduction of the MIC elucidated by comparing the ethidium bromide efflux in dose dependent manner in addition to ethidium bromide efflux inhibition and accumulation study using NorA overexpressing strain SA-1199B. Most potent compounds among these were able to restore the antibacterial activity of ciprofloxacin completely against SA-1199B. Structure activity relationship (SAR) studies and docking study of potent compounds 7 and 8 could elucidate the structural requirements necessary for interaction with the NorA efflux pumps. On the whole, compounds 7 and 8 have ability to reverse the NorA efflux mediated resistance and could be further optimized for development of potent efflux pump inhibitors. [ABSTRACT FROM AUTHOR]

Racemic mixtures of four stereoisomers are easily formed via many fundamental organic transformations, but the direct utilities of these mixtures have been less studied and remain large challenges to date. In this work, we introduce a new method, i.e. divergent dynamic kinetic resolution, to achieve the separation of racemic mixtures of four stereoisomers. The hypothesis was proved by using a N‐heterocyclic carbene‐catalyzed benzoin reaction, which afforded two separable diastereomeric products bearing three consecutive stereocenters with good to excellent enantioselectivties. We believe that this resolution protocol will find applications in more transformations. Providing a good resolution: An N‐heterocyclic carbene‐catalyzed benzoin reaction was employed to achieve the divergent dynamic kinetic resolution of racemic mixtures of four stereoisomers, affording two separable diastereomeric tetralones bearing three consecutive stereocenters with good to excellent enantioselectivties. [ABSTRACT FROM AUTHOR]

A simple and efficient synthesis of (E)-5-arylylidene-3-((substituted-ind-2-en-1-one)methyl)-3-aryl piperidine-2,6-diones from Baylis-Hillman acetates via bis -alkylation of aryl acetonitriles followed by facile domino bis -cyclization involving C–C bond and C–N bond formation reactions are described. [Display omitted] [ABSTRACT FROM AUTHOR]

Much research has been carried out with the aim to discover the therapeutic values of chalcone derivatives. Chalcones possess wide range of pharmacological activity such as antibacterial, antimalarial, antiprotozoal, antitubercular, anticancer, and antifungal agents etc. The presence of reactive α,β-unsaturated keto group in chalcones is found to be responsible for their biological activity. The rapid developments of resistance to antifungal agents, led to design, and synthesize the new antifungal agents. The derivatives of chalcones were prepared using Claisen-Schmidt condensation scheme with appropriate tetralone and aldehyde derivatives. Ten derivatives were synthesized and were biologically screened for antifungal activity. The newly synthesized derivatives of chalcone showed antifungal activity against fungal species, Microsporum gypseum. The results so obtained were superior or comparable to ketoconazole. It was observed that none of the compounds tested showed positive results for fungi Candida albicans nor against fungi Aspergillus niger. Chalcone derivatives showed inhibitory effect against M. gypseum species of fungus. It was found that among the chalcone derivatives so synthesized, two of them, that is, 4-chloro derivative, and unsubstituted derivative of chalcone showed antifungal activity superior to ketoconazole. Thus, these can be the potential new molecule as antifungal agent.

Background and objectives: Sleeping sickness and malaria alike are insect-borne protozoan diseases that share overlapping endemic areas in sub-Saharan Africa. The causative agent for malaria has developed resistance against all currently deployed anti-malarial agents. In the case of sleeping sickness, the currently deployed therapeutic options are limited in efficacy and activity spectra, and there are very few drug candidates in the development pipeline. Thus, there is a need to search for new drug molecules with a novel mode of actions. Materials and Methods: In the current study, an in vitro screening of a library of tetralone derivatives and related benzocycloalkanones was effected against T. b. brucei and P. falciparum. Results: Several hits with low micromolar activity (0.4−8 µM) against T. b. brucei were identified. Conclusions: The identified hits have a low molecular weight (

A methanolic extract of Juglans regia L. leaves was fractioned by various chromatographic techniques yielding a total of 40 metabolites belonging to megastigmane, tetralone, phenylpropanoid, neolignane and juglone glycosides. Ten unknown megastigmane glucoside derivatives (juglanionosides A-K, 1 – 10 ) and six unknown tetralone glucoside derivatives (juglanosides J-O, 11 – 16 ) together with 24 known compounds - among them 16 described for the first time in Juglans - were isolated. As characteristic structural feature, the previously undescribed compounds showed acylation of the sugar units with sinapic, ferulic, coumaric, benzoic or salicylic acid. Their chemical structures were elucidated on the basis of 1D and 2D NMR techniques, HRESIMS as well as CD spectroscopy. Absolute stereochemistry was revealed by mild alkaline hydrolysis and comparison of CD and polarimetric data to literature values. [ABSTRACT FROM AUTHOR]

Chalcone-like compounds3a–l, 2-(benzylidene)-3,4-dihydronaphthalen-1(2H)-one, were synthesized from the addition of different benzaldehyde derivatives (2a–l) to 1,2,3,4-tetrahydro-1-napthalone (1) in basic medium. Mn(OAc)3-mediated addition of dimedone (4) to chalcone-like compounds gave the spirobenzofuran derivatives (5a-l), 6,6-dimethyl-3-aryl-3′,4′,6,7-tetrahydro-1′H,3H-spiro[benzofuran-2,2′-naphthalene]-1′,4 (5H)-dione, in good yields. The structures of synthesized compounds5a–lwere elucidated on basis of spectral data (NMR, IR) and elemental analysis. In addition, their antibacterial activities were screened against some human pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

We present an enantioselective synthesis of cis-fused tricyclic 1-tetralones via oxidative kinetic resolution in the presence of cumene hydroperoxide (CHP) and guanidine-bisurea bifunctional organocatalyst. This reaction affords the corresponding α-hydroxylation products together with unreacted tetralones in good to high enantioselectivity, with s values as high as 42. The reaction was successfully applied for the synthesis of the core structure of a kainoid derivative, 4-(2-methoxyphenyl)-2-carboxy-3-pyrrolidineacetic acid (MFPA). [ABSTRACT FROM AUTHOR]

The total synthesis and structure determination of cis- and trans-flocoumafen was described. The key synthetic steps involve Knoevenagel condensation with p-methoxybenzaldehyde, in situ decarboxylation and intramolecular ring cyclization to construct the tetralone skeleton. Stereospecific reduction of the O-alkylated ketone 13 afforded good yield of precusor alcohol 5. Final coupling of alcohol 5 with 4-hydroxy-coumarin yielded flocoumafen (1). Separation and structure determination of cis- and trans-flocoumafen through 2D NMR analyses-assisted computer simulation techniques for the evaluation of anticoagulant activities are reported for the first time. This method is useful for generating the core tetralone skeleton of 4-hydroxycoumarin derivatives and provides a generalized access to various warfarin type anticoagulants.

The main purpose of this review is to summarize recent chemical syntheses and structural modifications of 4-hydroxycoumarin and its derivatives, of interest due to their characteristic conjugated molecular architecture and biological activities.

In the title compound, C28H27NO3, the cyclohexanone and isoxazole rings have envelope conformations, with the methylene and spiro C atoms as the flaps, respectively. The mean plane of the isoxazole ring is inclined slightly to the p-tolyl ring, making a dihedral angle of 14.20 (9)°, and is nearly perpendicular to the mean plane through the tetralone moiety and to the methoxyphenyl ring [dihedral angles = 83.41 (8) and 72.12 (9)°, respectively]. The crystal packing is stabilized mainly by van der Waals forces.

A redox-neutral, light-mediated functionalization of unactivated C(sp3)−H bonds via iminyl radicals is presented here. A 1,5-H transfer followed by the functionalization of a C(sp2)−H bond takes place in aqueous media producing a variety of elaborated fused ketones. Mechanistic investigations have revealed 1,5-H transfer as the reversible, rate-determining step in this transformation. Divergent scaffolds are also accessible via C(sp3)−N bond formation upon a careful choice of the reaction additives. [ABSTRACT FROM AUTHOR]

A multicomponent reaction between α-tetralone, 1 H-tetrazol-5-amine, and aromatic aldehyde, occurring upon microwave irradiation in acidic medium at 130°C, led to the formation of previously unknown 7-aryl-5,6,7,12-tetrahydrobenzo[ h]tetrazolo[5,1- b]quinazolines in 5-52% yields. [ABSTRACT FROM AUTHOR]