Search

The cyclization of 5,6-diarylpyrrolo[3,4-d]pyrimidine-2,4-diones containing a halogen atom in the ortho-position of one of the aryl rings, proceeding as intramolecular C–H arylation catalyzed by Ru(II) complexes, was studied. It was found that complexes Ru(NHC)(cymene)Cl2, where NHC = IPr [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene], IMes [1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], and their derivatives containing substituents at positions 4 and 5 of the imidazole ring, exhibit high catalytic activity. Based on the reaction studied, new representatives of pyrimido[5',4':3,4]pyrrolo[1,2-f]phenanthridine were obtained. [ABSTRACT FROM AUTHOR]

The development of transition metal-free 2-isocyanobiaryl-based reactions has received much attention due to the widespread presence of phenanthidine frameworks as products in pharmacological chemistry and materials science. This review article focuses on the achievements from 2013 until now in various metal-free catalyzed reactions and discusses challenging mechanisms and features of the transformations. Isocyanides, in particular, 2-isocyanobiaryls have attracted extensive attention, due to their distinctive properties in the field of synthetic chemistry. The preparation of various phenanthridine-containing compounds from these scaffolds has been investigated in the two last decades. Hence, the synthesis of valuable bioactive phenanthridines via coupling reaction/cyclization of 2-isocyanobiaryls with many kinds of organic compounds is highlighted in this review. [ABSTRACT FROM AUTHOR]

A solvent-free three-component reaction between phenanthridine, acetylenic ketones, and bis(polyfluoroalkyl) H-phosphonates proceeded at room temperature for 20–24 h to stereoselectively give the corresponding E-N-acylethenyl-6-bis(polyfluoroalkyl)phosphoryl-5,6-dihydrophenanthridines in up to 82% yield. [ABSTRACT FROM AUTHOR]

Pt(II) complexes supported by chelating, multidentate ligands containing π-extended, planar phenanthridine (benzo[c]quinoline) donors (RLPtCl) exhibit a promising in vitro therapeutic index compared with phenanthriplatin, a leading preclinical anticancer complex containing a monodentate phenanthridine ligand. Here, we report evidence for non-specific interactions of CF3LPtCl with DNA through intercalation-mediated turn-on luminescence in O2-saturated aqueous buffer. Brief irradiation with visible light (490 nm) was also found to drastically increase the activity of CF3LPtCl, with photocytotoxicity increased up to 87% against a variety of human cancer cell lines. Mechanistic studies highlight significantly improved cellular uptake of CF3LPtCl compared with cisplatin, with localization in the nucleus and mitochondria triggering effective apoptosis. Photosensitization experiments with 1,3-diphenylisobenzofuran demonstrate that CF3LPtCl efficiently mediates the generation of singlet dioxygen (1O2), highlighting the potential of RLPtCl in photodynamic therapy. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) with precise designable structures are becoming popular semiconductor materials for photocatalytic applications. In this study, a hydrazone-linked COFs (TFPT-ODH) material was constructed from the reversible polycondensation of 2,4,6-tris(4-formylphenyl)-1,3,5-triazine with oxalohydrazide. Thanks to the bottom-up strategy, the as-prepared TFPT-ODH exhibited satisfactory crystallinity, high thermal and chemical stability. The benefit of the combined effects of narrow band gap and efficient separation of photogenerated carriers, the photofunctional TFPT-ODH further demonstrated outstanding photocatalytic activity, stability, and recyclability in the photocatalytic cyclization reactions of 2-isocyanodiaryl compounds with phenylhydrazine. The photocatalytic mechanism for the photocyclization approach to phenylphenanthridines was proposed based on experimental data and spectrum techniques. Our work also demonstrates application in developing COFs-based photocatalysts for the photocatalytic cyclization of bioactive PAHs derivatives. [ABSTRACT FROM AUTHOR]

The precise activation of C–H bonds will eventually provide chemists with transformative methods to access complex molecular architectures. Current approaches to selective C–H activation relying on directing groups are effective for the generation of five-membered, six-membered and even larger ring metallacycles but show narrow applicability to generate three- and four-membered rings bearing high ring strain. Furthermore, the identification of distinct small intermediates remains unsolved. Here, we developed a strategy to control the size of strained metallacycles in the rhodium-catalysed C−H activation of aza-arenes and applied this discovery to tunably incorporate the alkynes into their azine and benzene skeletons. By merging the rhodium catalyst with a bipyridine-type ligand, a three-membered metallacycle was obtained in the catalytic cycle, while utilizing an NHC ligand favours the generation of the four-membered metallacycle. The generality of this method was demonstrated with a range of aza-arenes, such as quinoline, benzo[f]quinolone, phenanthridine, 4,7-phenanthroline, 1,7-phenanthroline and acridine. Mechanistic studies revealed the origin of the ligand-controlled regiodivergence in the strained metallacycles. The ability to selectively functionalize different sites on simple starting materials is a constant pursuit in organic chemistry. Here, the authors report a catalytic system to regioselectively differentiate and alkynylate different positions on azaarenes via rhodium catalysis. [ABSTRACT FROM AUTHOR]

A procedure has been developed for the direct Csp2–H functionalization of phenanthridine with a 1H-benzotriazole residue in the presence of Selectfluor® to build up Csp2–N bond. The procedure makes it possible to synthesize 6-(1H-benzotriazol-1-yl)phenanthridine in one step using commercially available starting materials and reagents. The product is an important substrate for further chemical transformations. [ABSTRACT FROM AUTHOR]

Phenanthridine readily undergoes one-pot N-acylvinylation/C-phosphorylation in the terminal acetylenic ketone—secondary phosphine oxide system at room temperature (acetonitrile, 48–72 h) in the absence of a catalyst to stereoselectively form (E)-N-acylvinyl-6-diorganylphosphoryl-5,6-dihydrophenanthridines in up to 88% preparative yield. Under similar conditions, secondary phosphine sulfides form a difficult-to-separate mixture of N-vinylation/C-phosphorylation products and adducts of phosphine sulfides with acetylenic ketones, while bis(2-phenylethyl)phosphine selenide gives only an adduct with acetylenic ketone in 78% yield. [ABSTRACT FROM AUTHOR]

A new easily scalable synthesis of the important for materials chemistry indolo[1,2-f]phenanthridine from commercially available 6-chlorophenanthridine was developed. The suggested transition metal catalyst-free and solvent-free procedure is more ecologically friendly and cost efficient then the known methods. The yields of indolo[1,2-f]phenanthridine synthesized from 6-chlorophenanthridine in three steps were 20% and 26% if the cyclization was carried out solvent-free and in THF in the presence of lithium 2,2,6,6-tetramethylpiperidide, respectively. [ABSTRACT FROM AUTHOR]

Spectral characteristics and luminescence under the photo- and electro-excitation of substituted dibenzthiophene sulfone and phenanthridine were studied in this paper. Diphenylamines are substituents introduced in the 2nd and 7th positions (linear configuration) or the 3rd and 6th positions (angular configuration) of dibenzthiophene sulfone or phenanthridine. All molecules show delayed fluorescence, both in solutions and films produced by thermal vacuum deposition. The value of the energy gap between the S1 and T1 states has been estimated and is shown to depend not only on the spatial arrangement of the fragments among themselves (linear or angular), but also on the nature of the substituent in diphenylamine. The highest electroluminescence brightness was found for the molecules, in which triplet levels are involved, both through the process of triplet–triplet annihilation and through thermally activated delayed fluorescence. [ABSTRACT FROM AUTHOR]

In the present study, one new benzophenanthridine alkaloid derivative, 2′ -methoxy-3′ -methyltetrahydrofuran-(5′→6)-dihydrochelerythrine (1) was separated from Eomecon chionantha Hance. The chemical structure of 1 was identified based on extensive spectroscopic data including UV, HR-ESI-MS, 1D and 2D NMR. [ABSTRACT FROM AUTHOR]

Two new Hg(II), {[Hg(phend)2Cl2].(0.5 phend) (1) and [Hg(phend)2Br2].(0.5 phend) (2)} and a new Cd(II) {[CdI2(phend)2] (3)} complexes, containing phenanthridine (phend) ligand, have been synthesized from the reaction of HgCl2 (1), HgBr2(2), and CdI2 (3) with phend, respectively. The complexes were thoroughly characterized by elemental analysis, FT-IR, UV, NMR, and emission spectroscopies. Moreover, single-crystal X-ray diffraction studies were undertaken to examine the coordination geometry of complexes 1-3 in the solid-state. According to X-ray analysis, the complexes 1 (τ4 = 0.77) and 2 (τ4 = 0.74) exhibit distorted tetrahedral geometries and 3 (τ4 = 0.90) shows slightly distorted tetrahedral geometry. So, complexes 1 and 2 have similar structures. However, the emission maximum of complex 1 is stronger than 2, which indicates that the different coordinated counter anions play a significant role in determining the photoluminescence properties of the complexes. Meanwhile, all complexes 1-3 have stronger emissions than free phend ligand in the DMSO solution. [ABSTRACT FROM AUTHOR]

An increasing amount of evidence suggests that transmembrane member 16A (TMEM16A)-encoded Ca2+-activated Cl− channels play a crucial role in regulating tumorigenesis. Therefore, specific and potent TMEM16A inhibitors have been proposed to potentially be useful for the treatment of cancer. During drug screening, we found that benzophenanthridine alkaloids (sanguinarine, sanguinarium chloride, sanguinarine nitrate, ethoxysanguinarine, chelerythrine, and dihydrosanguinarine) potently inhibited the recombinant TMEM16A current. The IC50 and Emax values for TMEM16A inhibition of six tested benzophenanthridine alkaloids were 5.6–12.3 μM and 77–91%, respectively. These benzophenanthridine alkaloids also significantly inhibited the endogenous TMEM16A currents and proliferation, migration, and induced apoptosis in LA795 lung adenocarcinoma cells. These data demonstrate that benzophenanthridine alkaloids are novel TMEM16A inhibitors and are potentially useful in specific cancer therapies. These findings also provide new insight for the development of TMEM16A inhibitors. [ABSTRACT FROM AUTHOR]

The reaction of Cd(NO3)2 · 4H2O and Eu(NO3)3 · 6H2O or Tb(NO3)3 · 6H2O with potassium 3,5-di-tert-butylbenzoate (Kbzo) and N-donor ligands (1,10-phenanthroline (phen), 2,4-lutidine (2,4-lut), 3,4-lutidine (3,4-lut), phenanthridine (phtd), 2,3-cyclododecenopyridine (cdpy), acridine (acr)) afforded heterometallic LnCd2 complexes: [EuCd2(bzo)7(EtOH)2(phen)] (2), [LnCd2(bzo)7(2,4-lut)4] (Ln = Eu (3), Tb (4)), [EuCd2(bzo)7(H2O)2(2,4-lut)2] · MeCN (5), [EuCd2(NO3)(bzo)6(EtOH)2(2,4-lut)2] (6), [EuCd2(bzo)7(H2O)(EtOH)(3,4-lut)2] · 5EtOH (7), 3[EuCd2(bzo)7(H2O)2(phtd)2] · 4phtd (8), [EuCd2(bzo)7(EtOH)3(cdpy)] (9), 2[EuCd2-(bzo)2(EtOH)4] · acr (10). The structures of complexes 2, 3, and 5–10 were determined by single-crystal X-ray diffraction. The isostructurality of complexes 3 and 4 was confirmed by powder X-ray diffraction. The structure of the trinuclear {Ln2Cd} metal core is stable and independent of the type of peripheral ligands coordinated to cadmium atoms. Photoluminescent properties of compounds 3 and 4 were studied. [ABSTRACT FROM AUTHOR]

Ionic liquids and reagents (Selectfluor, DABSO) derived from DABCO, DABCO as piperazine source Graph: Scheme 7 A series of new ionic liquids that were derived from DABCO were applied as reusable catalysts for aza-Michael reactions at room temperature in the absence of organic solvents.[9] The most effective of these ionic liquids was [DABCO-PDO][OAc] in the amount of 10 mol % (Scheme 8). Graph: Scheme 73 B Other reagents derived from DABCO b Several other reagents have been described in the literature, which have been designed on the basis of DABCO, as well as some interesting and useful synthetic applications of DABCO have been outlined. Graph: Scheme 81 B The biological properties of DABCO derivatives b Only limited data have been published on the biological properties of compounds derived from DABCO, but the currently available studies indicate that further efforts toward the characterization of biological activity in this class of compounds should be supported. [Extracted from the article]

Association of ethidium bromide and caffeine in aqueous solution was studied using spectrophotometry. The results were analyzed using a molecular dimer heteroassociation model. The molecular association equilibrium constants were determined. The experimental absorption spectrum of a mixture of heterocyclic molecules was deconvoluted into individual components using a regularization method. Quantitative information on the structure of the heterocomplex was obtained using data for the individual spectral components. The distance and angle between point transition dipole moments of the heterogeneous molecules were 0.3 nm and 16o. A calculation of the relative contents of different types of associates in a mixed solution showed that heteroassociation of the molecules decreased the effective concentration of ethidium bromide and, accordingly, the mutagenic activity of the dye. [ABSTRACT FROM AUTHOR]

Representatives of the new heterocyclic system, pyrimido[5’,4’:3,4]pyrrolo[1,2-f]phenanthridine, were obtained via the intramolecular C-H-arylation of 6-aryl-5-(2-bromophenyl) pyrrolo[3,4-d]pyrimidine-2,4-diones catalyzed by palladium complexes with N-heterocyclic carbene ligands (Pd/NHC). [ABSTRACT FROM AUTHOR]

Currently, one of the most challenged points to expand the use of viability PCR technique is achieving the complete exclusion of dead cells amplification signals, thus avoiding the overestimation of live cells population. Considering that, and based on the hypothesis that DNA may be retained by microtube walls, the impact of the microtube was addressed on signals from live and heat-killed cells. A double-dye reagent, PEMAX™, which comprises a mix of photo-reactive azide forms of phenanthridium, was used in this work. We found that if both the incubation and the photoactivation steps are carried out in different microtubes, the dead cell signal is greatly reduced than when those steps are done in the same tube. Therefore, the strategy depicted in this study presents a simple and efficient step in minimizing false-positive signal when employing viability PCR. [ABSTRACT FROM AUTHOR]

This study was conducted to assess the anti-inflammatory effect of a novel synthesized phenanthridine alkaloid (PHE-4i) and to examine the possible involvement of hydrogen sulfide (HS) in anti-inflammatory mechanism. The synthesized phenanthridine derivative PHE-4i (2, 5, and 10 mg/kg) was administered intraperitoneally to rats. One hour following treatment, inflammation was induced by intraplantar injection of carrageenan (1 %), in the hind paw. Paw volume as the index of inflammation was measured before and after carrageenan injection. Neutrophil sequestration into the hind paw was quantified by measuring tissue myeloperoxidase (MPO) activity and was compared for the inhibition of HS production. Pretreatment with PHE-4i significantly reduced carrageenan-induced hind paw weight, MPO activity, leukocyte infiltration, and HS production in a dose-dependent manner ( p < 0.001). These results indicate that the anti-inflammatory effect of PHE-4i on carrageenan-induced rat paw oedema could be via the inhibition of the gaseous mediator HS. [ABSTRACT FROM AUTHOR]

9-Diazofluorene reacted with phenyl prop-1-yn-1-yl sulfone in diethyl ether at 20°C (3-4 days) to give 5'-(benzenesulfonyl)-4'-methylspiro[fluorene-9,3'-pyrazole] (3 H-pyrazole) as the only 1,3-dipolar cycloaddition product formed according to the von Auwers rule. On heating in boiling ethanol for 0.5 h, 5'-(benzenesulfonyl)-4'-methylspiro[fluorene-9,3'-pyrazole] underwent partial reversible isomerization into a 4 H-pyrazole derivative, 3-(benzenesulfonyl)-3a-methyl-3a H-dibenzo[ e, g]indazole, whereas in toluene at 180°C (40 min) it was completely converted into thermodynamically more stable 2-(benzenesulfonyl)-3-methylpyrazolo[1,5- f]phenanthridine with a 1 H-pyrazole fragment. 3a-Methyl-2 H-dibenzo[ e, g]indazol-3(3a H)-one was formed when the 3 H- and 4 H-pyrazoles were kept in glacial acetic acid at 20°C in the presence of a catalytic amount of sulfuric acid, followed by treatment with water. Alcoholic potassium hydroxide promoted reversible isomerization of the 3 H-pyrazole into 5'-(benzenesulfonyl)-4'-methylidene-2',4'-dihydrospiro[ fluorene-9,3'-pyrazole]. [ABSTRACT FROM AUTHOR]

For the first time, a series of separate dynamic effects are reported at different temperatures within a particular enaminoester 4 involving a phenanthridine namely dimethyl-2-(6-(2-methylindol-1-yl)phenanthridine-5(6H)-yl) maleate. These effects are attributed to restricted rotation around the two single bonds such as heteroaryl-carbon (N[InlineMediaObject not available: see fulltext.]CH-N) and nitrogen-carbon (N[InlineMediaObject not available: see fulltext.]C=CH). Rotational energy barriers (Δ G) for these interconversion processes are 44.88 and 44.63 ± 1 kJ mol, respectively, in rotational isomers. In addition, theoretical studies on the basis of rotational around the same bonds were investigated using an ab initio method at HF/6-31G(d,p) and B3LYP/6-31G(d,p) levels of theory. Theoretical activation parameters including Δ H, Δ G, Δ S, and kinetic parameters involving E were calculated in the presence of a solvent medium (CDCl) at experimental temperature. The results indicated that the HF/6-31G(d,p) level provides more accurate data in comparison with the B3LYP method with the same basis set [6-31G(d,p)] for compound 4 and they are in relative agreement with dynamic H NMR data. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Two new gold(III) complexes of phenanthridine (phend) ligand, gold(III) trichlorophenanthridine ([Au(phend)Cl]) and gold(III) tribromophenanthridine ([Au(phend)Br]), have been synthesized from the reaction of HAuCl∙3HO and AuBr with phend, respectively, and characterized by elemental analysis, luminescence, IR, H and C NMR spectroscopy, and their structures were studied by the single-crystal diffraction method. [Au(phend)Cl] crystallizes in the space group P2/ n of the monoclinic system with a = 7.6661(7) Å, b = 20.816(2) Å, c = 17.4906(16) Å, β = 98.500(7)°, and Z = 8. [Au(phend)Br] crystallizes in the space group Pī of the triclinic system with a = 10.2137(4) Å, b = 11.1191(4) Å, c = 14.6540(6) Å, α = 68.631(3), β = 71.706(3), γ = 66.098(3)°, and Z = 4. There are two molecules of the complex in the asymmetric units and in both molecules, the geometry at the gold(III) centers is square planar, formed by one nitrogen atom of phend and three chloride or bromide ions. Weak hydrogen bonding, π-π interaction, together with interhalogen contact, may play an important role in determining the structure of both complexes. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The chromatographic isolation and characterisation of the four compounds present in the quaternary phenanthridine veterinary trypanocidal agent, isometamidium chloride hydrochloride (ISM), is reported. The isolated compounds were unambiguously characterised using spectroscopic (NMR, UV, IR and MS) methods as 3-amino-8-[3-(3-carbamimidoyl-phenyl)-triazenyl]-5-ethyl-6-phenylethidium ( 1a) and related isomers, 8-amino-3-[3-(3-carbamimidoyl-phenyl)-triazenyl]-5-ethyl-6-phenylethidium, 3,-8-diamino-7-[3-(3-carbamimidoyl-phenyl)-triazenyl]-5-ethyl-6-phenylethidium and 3,-8- bis[3-(3-carbamimidoyl-phenyl)-triazenyl]-5-ethyl-6-phenylethidium. During the course of this study, it was realised that the nature of the solvent used in the NMR study was critical as in DMSO-d the quaternary group in the compounds was reduced to dihydro forms (e.g. 2a). [ABSTRACT FROM AUTHOR]

In order to study cell electroporation in situ, polymer devices have been fabricated from poly-dimethyl siloxane with transparent indium tin oxide parallel plate electrodes in horizontal geometry. This geometry with cells located on a single focal plane at the interface of the bottom electrode allows a longer observation time in both transmitted bright-field and reflected fluorescence microscopy modes. Using propidium iodide (PI) as a marker dye, the number of electroporated cells in a typical culture volume of 10-100 μl was quantified in situ as a function of applied voltage from 10 to 90 V in a series of $${\sim}$$ 2-ms pulses across 0.5-mm electrode spacing. The electric field at the interface and device current was calculated using a model that takes into account bulk screening of the transient pulse. The voltage dependence of the number of electroporated cells could be explained using a stochastic model for the electroporation kinetics, and the free energy for pore formation was found to be $$45.6\pm 0.5$$ kT at room temperature. With this device, the optimum electroporation conditions can be quickly determined by monitoring the uptake of PI marker dye in situ under the application of millisecond voltage pulses. The electroporation efficiency was also quantified using an ex situ fluorescence-assisted cell sorter, and the morphology of cultured cells was evaluated after the pulsing experiment. Importantly, the efficacy of the developed device was tested independently using two cell lines (C2C12 mouse myoblast cells and yeast cells) as well as in three different electroporation buffers (phosphate buffer saline, electroporation buffer and 10 % glycerol). [ABSTRACT FROM AUTHOR]

The preliminary results describe synthesis of a series of novel 6-(4-((substituted-1 H-1,2,3-triazol-4-yl)methyl)piperazin-1-yl)phenanthridine analogs using hybrid approach employing copper(I)-catalyzed azide-alkyne cycloaddition and their evaluation as antiproliferative agents against four cancer cell lines by MTT assay. Among the synthesized compounds, 7g and 7h showed good activity against all the test cell lines. In particular, 7g (IC = 9.73 ± 4.09 µM) exhibited excellent activity against THP1 cancer cell line, and 7h (IC = 7.22 ± 0.32 µM) emerged as more active compound than the standard drug etoposide against HL60 cancer cell line. [ABSTRACT FROM AUTHOR]

Aroylketenes generated by thermolysis of 6-aryl-2,2-dimethyl-4 H-1,3-dioxin-4-ones reacted with ( Z)-2-[4a,7,10-trimethyl-1,3,4,4a,5,10b-hexahydrophenanthridin-6(2 H)-ylidene]acetamide to give ( Z)-3-aryl-3-hydroxy- N-{(Z)-2-[4a,7,10-trimethyl-1,3,4,4a,5,10b-hexahydrophenanthridin-6(2 H)-ylidene]acetyl}acrylamides whose structure was confirmed by X-ray analysis. [ABSTRACT FROM AUTHOR]

A three-component acid-catalyzed cyclocondensation of 5-aminoquinoline and 5-aminoisoquinoline with aromatic aldehydes and cyclopentadiene leads to (6S*,6aR*,9aS*)-6-aryl-6,6a,7,9a-tetrahydro-5 H-cyclopenta[c]-1,7-and (6S*,6aR*,9aS*)-6-aryl-6,6a,7,9a-tetrahydro-5 H-cyclopenta[c]-1,8-phenanthrolines. [ABSTRACT FROM AUTHOR]

A simple and efficient radical coupling of 2-isocyanobiphenyl with ethers was developed, providing a variety of 6-alkylated phenanthridines. Both cyclic and acyclic ethers are suitable substrates for this transformation, which comprised the functionalization of two C-H bonds: the sp C-H of ether and sp C-H of phenyl group. The kinetic isotope effect (KIE) revealed that the cleavage of sp C-H bond would be involved in the rate-determining step. [ABSTRACT FROM AUTHOR]

The fluorescence properties of selected benzo[c]phenanthridines (BPs) were examined. The effect of structure, pH and solvent on the fluorescence properties has been investigated. It was found out that the presence of charged iminium nitrogen significantly decreased the fluorescence of the compounds. The fluorescence (intensity as well as emission spectra shape) of the investigated compounds was significantly dependent on pH as well as used solvent. The utilization in epigenetic modification mechanisms studies as demethylase probe and as possible pH indicator was suggested. [ABSTRACT FROM AUTHOR]

Three-component condensation reactions between azines (isoquinoline or phenanthridine) and acetylenic esters were undertaken in the presence of phenol derivatives (2,6-di-tert-butyl-phenol, 2,4-di-tert-butyl-phenol, 2,6-dimethyl phenol and 2,4-dimethyl phenol) for generation of C-arilation in good yields. The reactions proceeded smoothly at room temperature without using any catalyst. This method is very useful to functionalize aza-aromatic compounds in a one-pot operation. Graphical Abstract: [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

A concise synthesis of pyrrolo[1,2- f]phenanthridine-annulated polycyclic heterocycles has been achieved in good yields by palladium-catalyzed intramolecular direct arylation reaction. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Evaluation of metabolic pathways is one of the challenging areas in biological and pharmaceutical sciences. Phenanthridine oxidation to phenanthridinone is used commonly to study aldehyde oxidase activity. This reaction could pass through phenanthridine N-oxide intermediate. In the present study, the application of multivariate curve resolution, optimized by alternating least squares (MCR-ALS) to investigate this metabolic pathway has been described. The results obtained from MCR-ALS analysis along with those obtained from the use of potassium ferrocyanide method indicated that phenanthridine is directly oxidized to phenanthridinone by rat liver aldehyde oxidase without passing through phenanthridine N-oxide intermediate. It was also found that the later compound is not metabolized by this enzyme. [ABSTRACT FROM AUTHOR]

In a new multicomponent reaction phenanthridine reacts with isocyanides and malonitrile in the presence of benzaldehyde derivatives to produce 2-aryl-3-(alkyl- or arylimino)-2,3-dihydropyrrolo[1,2- f]phenanthridine-1,1(12b H)-dicarbonitrile in a simple, mild, and efficient protocol in excellent yields. Graphical Abstract: [MediaObject not available: see fulltext.] [ABSTRACT FROM AUTHOR]