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A convenient approach to the synthesis of 1-aroyl-3,4-dihydro-β-carbolines via Pictet–Spengler reaction has been developed. A variety of reagents, such as unsaturated aldehydes, ketones, maleic anhydride in the construction of functionally diverse indolizino[8,7-b]indole, and pyrido[1,2-a:3,4-b’]diindole derivatives has been used. The developed method is a simple and convenient procedure giving medium and excellent yields, showing a wide functional group tolerance.

Various 4′-R-substituted phenyl azacyclic allenes were synthesized in good yields, and their thermal transformations were studied. For the first time, the obtained rearrangement products—new N-bridged cyclopenta[a]indenes, and the corresponding parent allenes were evaluated as potential inhibitors of acetyl- and butyrylcholinesterase. Among the tested compounds, the allene derivative 2g proved to competitively inhibit human AChE with inhibition constant value (Ki) in the low micromolar range.

Nature-inspired, bridged polycyclic molecules share low similarity with currently available drugs, containing preferentially planar and/or achiral moieties. This "Escape from Flatland" scenario, aimed at exploring pharmacological properties of atypical molecular scaffolds, finds interest in synthetic routes leading to tridimensional-shaped molecules. Herein we report on the synthesis of N-bridged cyclopenta[a]indene derivatives, achieved through microwave-assisted thermal rearrangement of allene 3-benzazecines with high diastereoselectivity. The biological evaluation disclosed selective inhibition of human acetylcholinesterase or butyrylcholinesterase, depending on the substitution around the molecular core, which was rationalized by means of docking simulations. The most potent BChE inhibitor 31 was effective in neuroprotection from glutamatergic excitotoxicity and displayed low intrinsic cytotoxicity and good brain penetration. Overall, compound 31 and its close congeners 34 and 35 acted as multitarget agents addressing different biological events involved in neurodegeneration, particularly in the progression of Alzheimer's disease.

A convenient protocol for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines with various electron-withdrawing substituents at C-2 atom is described. This approach is based on the two-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines with α,β-unsaturated ketones, nitroalkenes and acrylonitrile. Depending on the selected substrates, the reaction was performed in TFE under reflux or under microwave irradiation. Only for the two examples, a transition metal catalyst was used.

The thermolysis reactions of benzoazacyclodecatrienes under microwave irradiation conditions in toluene at 150 °C afforded complex azabenzo[a]cyclopropa[cd]azulene and (epiminomethano)cyclopenta[a]indene frameworks. Cyclopropanes were established as intermediates of the ultimate thermolysis products.

A novel and original protocol for the preparation of complex framework compounds containing a vinylcyclopropane (VCP) fragment is presented by means of UV conversion of cyclopentene (CP) derivatives under standard conditions, providing high yields of target products in an unprecedented atom economical reversible step. The reverse transformation of compounds with vinylcyclopropyl moieties into CP derivatives takes place in the presence of trifluoroacetic acid at room temperature. A one-pot approach for the synthesis of VCPs from the corresponding benzoazacyclic allenes has also been developed and the mechanisms of mutual rearrangements of both VCP and CP have been rationalized by DFT calculations.

Synthesis of novel C3-substituted 5,6-dihydropyrrolo[2,1-a]isoquinolines via a three-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines, terminal alkynes and CH-acids under microwave irradiation in dry acetonitrile is described. The method developed enables the obtainment of highly functionalized compounds with pharmacophore groups, which are potentially biologically active.

Aim: Enamino 3-benzazecine compounds, incorporating the C6-C8 allene system, were synthesized and evaluated in vitro as inhibitors of P-glycoprotein (P-gp) and/or multidrug resistance-associated protein 1 (MRP1), two efflux pumps mainly connected with multidrug resistance (MDR) in cancer cells. Results & methodology: Most of the synthesized compounds were selective P-gp inhibitors in Calcein-AM uptake assay. Structure–activity relationships (SARs) pointed out that CO2Me derivatives are more potent than acetyl derivatives, and 10,11-dimethoxy compounds are five to tenfold more potent inhibitors than the respective unsubstituted compounds, and that the P-gp inhibition potency is mainly related to volume parameters. Conclusion: Nanomolar P-gp inhibitors, such as 23 (IC50 = 4.2 nM), restored the antiproliferative activity of doxorubicin in multidrug-resistant cells. The observed activities showed that 3-benzazecine-based compounds may be promising MDR reversers.

We report an efficient domino reaction for synthesizing new pyrrolo[2,1-a]isoquinolines from 1-aryl-3,4-dihydroisoquinolines and vinyl ethynyl ketones. We also address the chemical selectivity of vinyl ethynyl ketones; i.e., adduct formation by the double or triple bond. The reaction outcome depends on the solvent, temperature, microwave irradiation, and catalyst. Donor substituents in the initial isoquinolines provide a regioselective addition to double or triple bonds.

Marine alkaloids belonging to the lamellarins family, which incorporate a 5,6-dihydro-1-phenylpyrrolo[2,1-a]isoquinoline (DHPPIQ) moiety, possess various biological activities, spanning from antiviral and antibiotic activities to cytotoxicity against tumor cells and the reversal of multidrug resistance. Expanding a series of previously reported imino adducts of DHPPIQ 2-carbaldehyde, novel aliphatic and aromatic Schiff bases were synthesized and evaluated herein for their cytotoxicity in five diverse tumor cell lines. Most of the newly synthesized compounds were found noncytotoxic in the low micromolar range (&lt, 30 &mu, M). Based on a Multi-fingerprint Similarity Search aLgorithm (MuSSeL), mainly conceived for making protein drug target prediction, some DHPPIQ derivatives, especially bis-DHPPIQ Schiff bases linked by a phenylene bridge, were prioritized as potential hits addressing Alzheimer&rsquo, s disease-related target proteins, such as cholinesterases (ChEs) and monoamine oxidases (MAOs). In agreement with MuSSeL predictions, homobivalent para-phenylene DHPPIQ Schiff base 14 exhibited a noncompetitive/mixed inhibition of human acetylcholinesterase (AChE) with Ki in the low micromolar range (4.69 &mu, M). Interestingly, besides a certain inhibition of MAO A (50% inhibition of the cell population growth (IC50) = 12 &mu, M), the bis-DHPPIQ 14 showed a good inhibitory activity on self-induced &beta, amyloid (A&beta, )1&ndash, 40 aggregation (IC50 = 13 &mu, M), which resulted 3.5-fold stronger than the respective mono-DHPPIQ Schiff base 9.

Nature-inspired, bridged polycyclic molecules share low similarity with currently available drugs, containing preferentially planar and/or achiral moieties. This "Escape from Flatland" scenario, aimed at exploring pharmacological properties of atypical molecular scaffolds, finds interest in synthetic routes leading to tridimensional-shaped molecules. Herein we report on the synthesis of

Various 4'-R-substituted phenyl azacyclic allenes were synthesized in good yields, and their thermal transformations were studied. For the first time, the obtained rearrangement products-new N-bridged cyclopenta[a]indenes, and the corresponding parent allenes were evaluated as potential inhibitors of acetyl- and butyrylcholinesterase. Among the tested compounds, the allene derivative 2g proved to competitively inhibit human AChE with inhibition constant value (K

A convenient protocol for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines with various electron-withdrawing substituents at C-2 atom is described. This approach is based on the two-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines with α,β-unsaturated ketones, nitroalkenes and acrylonitrile. Depending on the selected substrates, the reaction was performed in TFE under reflux or under microwave irradiation. Only for the two examples, a transition metal catalyst was used.

A number of aza-heterocyclic compounds, which share the 5,6-dihydropyrrolo[2,1-a]isoquinoline (DHPIQ) scaffold with members of the lamellarin alkaloid family, were synthesized and evaluated for their ability to reverse in vitro multidrug resistance in cancer cells through inhibition of P-glycoprotein (P-gp) and/or multidrug-resistance-associated protein 1. Most of the investigated DHPIQ compounds proved to be selective P-gp modulators, and the most potent modulator, 8,9-diethoxy-1-(3,4-diethoxyphenyl)-3-(furan-2-yl)-5,6-dihydropyrrolo[2,1-a]isoquinoline-2-carbaldehyde, attained sub-micromolar inhibitory potency (IC50 : 0.19 μm). Schiff bases prepared by the condensation of some 1-aryl-DHPIQ aldehydes with p-aminophenol also proved to be of some interest, and one of them, 4-((1-(4-fluorophenyl)-5,6-dihydro-8,9-dimethoxypyrrolo[2,1-a]isoquinolin-2-yl)methyleneamino)phenol, had an IC50 value of 1.01 μm. In drug combination assays in multidrug-resistant cells, some DHPIQ compounds, at nontoxic concentrations, significantly increased the cytotoxicity of doxorubicin in a concentration-dependent manner. Studies of structure-activity relationships and investigation of the chemical stability of Schiff bases provided physicochemical information useful for molecular optimization of lamellarin-like cytotoxic drugs active toward chemoresistant tumors as well as nontoxic reversers of P-gp-mediated multidrug resistance in tumor cells.

Thieno[2,3-c]pyrrolines bearing a branched substituent at the nitrogen atom reacted with dehydrobenzene, furnishing thienylaziridines. N-Benzyl-substituted thienopyrroline under the reaction conditions gave a Stevens rearrangement product, 6-benzyl-5-phenylthieno[2,3-c]-pyrroline.

Introduction: Nowadays the stereotactic radiotherapy (SRT) of clinical stage I-II lung cancer patients is the choice of the treatment modality for functionally inoperable patients. It shows safety and high efficiency in achieving local control. Though there is a range of unsolved issues connected with the prediction of the treatment efficiency and frequency of complications, an integration of new technologies in the planning and treatment process allows widening the search of the predictive factors. Material and methods. Since 2014, 39 patients (17 T1N0M0 patients, 22 T2N0M0 patients) with clinical stage I-IIa lung cancer have undergone SRT. The majority of patients (35) have been recognized as functionally inoperable due to the concurrent broncho-pulmonary pathology, 4 conditionally operable patients have refused an operation. 11 patients had the primary multiple tumors in their anamneses. 36 patients had a peripheral tumor. The options for the fractionation were: 10 Gy × 5 fractions (n = 26) and 7 Gy × 8 fractions (n = 13) - BED = 100 Gy. Results. The median follow-up was 26 months (range: 3-38 months). The 2-year local control was 94%. The isolated local recurrences were not registered. Overall and 2-year recurrence-free survival rate was 84% (95% CI, 70-99) and 83.2% (95% CI: 70.5-99) respectively. During the first year, 4 patients (10%) had the locoregional and distant progression and 3 of them died. 7 patients had experienced pulmonary toxicity of grade 2 or more. One patient with central tumor died from pulmonary hemorrhage (toxicity of grade 5). Grade 3 chest pain was observed in 2 patients, one of them had a rib fracture. One-factor analysis, revealed a reliable influence of the fractionation regimen (р = 0.04) and, close to reliability, the initial SUVmax level (р = 0.07) on the prognosis. A reliable relationship between the radiation toxicity level and dosimetric radiation index (V10, V5, MLD) was not registered. There was a tendency to reliable correlation with the total lung capacity indices (р = 0.058). Conclusions. A search for additional treatment efficiency and toxicity predictors of SRT treatment should include modern approaches to planning and delivery. The total dose delivery regimen and initial tumor SUVmax can be predictive efficiency factors, while the pulmonary tissue volume can be a predictive toxicity factor.

The reaction between dehydrobenzene and tetrahydropyrido[4,3-d]pyrimidin-4-ones condensed with isoxazole, thiazole, thiadiazole, or triazole rings resulted in Hofmann cleavage of the tetrahydropyridine moiety with the formation of 6-vinyl-substituted pyrimidones fused with the corresponding azole rings.

An efficient approach to the synthesis of indolizines and pyrrolo[2,1–a]isoquinolines based on a domino reaction is described. The reactivity of the derivatives and the structure-activity analysis are carried out in a number of the obtained compounds. We found a hit showing high cytotoxicity on tumor cells (IC50 = 5.92 ± 0.08 µM) whose cytotoxic effect is comparable to that of the known topoisomerase I inhibitor camptothecin.

The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now.

An efficient synthesis of pyrrolo[2,1-a]isoquinolines by a domino reaction from a variety of 3,4-dihydropyrrolo[2,1-a]isoquinolines and α,β-unsaturated aldehydes in the absence of catalyst in good yields under microwave irradiation, is reported.

1,2,3,4-Tetrahydroisoquinolines bearing phenacyl group at the nitrogen atom in their reaction with benzyne in acetonitrile undergo ring expansion to give 1H-3-benzazepines.

Three-component reactions of cotarnine chloride with silver acetylides and methyl propiolate or ethynyl methyl ketone in acetonitrile, as well as two-component reactions of 5-phenylethynyl-substituted tetrahydro[1,3]dioxolo[4,5-g]isoquinoline with alkynes in various solvents were studied. Performing them in 2,2,2-trifluoroethanol as the solvent, 10-phenylethynyl-substituted tetrahydro[1,3]dioxolo[4,5-i]-[3]benzazocines were obtained in good yields.

A novel effective protocol towards indolo[2,1-a]isoquinolinones via aryne-induced migration of aryl-anion in aryloxy substituted 3,4-dihydroisoquinolines is reported. These novel 12a-aryl substituted indoxylisoquinolines exhibit fluorescence properties and are characterized by green-shifted spectra and moderate quantum yields.

A route towards pyrrolo[2,1-a]isoquinolines through a 3CR of 1-aroyl dihydroisoquinolines, activated alkynes and alcohols has been developed.

Cyanomethyl-substituted tetrahydroisoquinolines and tetrahydrothieno[3,2-c]pyridines were synthesized by multicomponent reaction of the dihydro analogues of aforesaid systems with benzyne and acetonitrile. The products obtained relate to alkaloids of isoquinoline family of 1,2,3,4-tetrahydro level.

The facile synthesis of 1-oxo-pyrrolo[2,1-a]isoquinolines from the reaction of 1-aroyl-3,4-dihydroisoquinolines and symmetrical alkynes in toluene is described. The novel compounds contain functional groups that are suitable for further modification.

1-(p-Methoxyphenyl)tetrazolyl-substituted 6,7-dimethoxy(6,7-methylenedioxy)-1,2,3,4-tetrahydroisoquinolines formed tetrazolyl-substituted azocines in high yields by using activated alkynes. Unsubstituted at 6,7,8-aromatic fragment 1-tetrazolylisoquinoline interacted in several pathways forming tetrazolyl-substituted azocines, 1-tetrazolyl-1-R-vinylisoquinolines and 3-azaspiro[5.5]undeca-1,7,9-triene. ispartof: MOLECULES vol:23 issue:11 ispartof: location:Switzerland status: published

Three-component reactions of tetrahydropyrrolo[1,2-a][1,4]benzodiazepines with methyl propiolate or acetylacetylene and СН, NH, SH, and ОН acids were studied in various solvents. The reaction direction is assumed to depend on the nucleophilicity of anion, formed through deprotonation of acid by the anionic center of initial Michael-type zwitterion.

2-(Chloromethyl)-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3Н)-ones reacted with acetylenedicarboxylate ester, methyl propiolate or acetylacetylene, forming mixtures of 2-(chloromethyl)-5,6,7,10-tetrahydropyrimido[5',4':4,5]thieno[3,2-d]azocin-4(3Н)-ones and 2'-chloromethyl-6'-methylidene-2,3-dihydro-1Н-spiro[pyrido[4,5']thieno[2,3-d]pyrimidin]-4'(3'H)-ones in various ratios. Analogous products were also obtained in the reaction of 2-(methoxymethyl) derivative with methyl propiolate, while using 2-[(morpholin-4-yl)-methyl] derivative in a similar reaction led to the formation of a more complex product mixture.

1-Aryl-substituted tetrahydrothieno[3,2-с]pyridines easily undergo domino reactions with activated alkynes, giving good yields of the corresponding tetrahydrothieno[2,3-d]azocines. The reactions of 1-methyl-substituted tetrahydrothieno[3,2-с]pyridine were more complicated.

The regioselectivity of dehydrobenzene reaction with 10-substituted benzo[b][1,6]naphthyridines was found to depend on electronic effects due to the C-10 substituent. Stevens rearrangement of 10-cyano-substituted naphthyridines produced 1-alkyl-2-phenyltetrahydrobenzonaphthyridines. 10-Carbamoyl-substituted naphthyridines underwent Hoffman cleavage of the tetrahydropyridine ring, giving 3-phenylallylaminomethyl-2-vinylquinolines.

The synthesis of pharmacologically relevant isoquinoline-tetrazoles and benzazocine-tetrazoles via sequential azido-Ugi and alkyne-induced ring-expansion reactions starting from cotarnine chloride are reported. A one-pot, multicomponent reaction protocol toward the ring-expanded product is also described.

The three-component reaction of 4-phenyl-, p-methoxyphenyl-, and thienylpyrrolo[1,2-a][1,4]benzo-diazepines with methyl propiolate and indole in dichloromethane proceeds through opening of the diazepine ring. The major transformation products isolated are substituted pyrroles, namely, 1-(2-aminomethylphenyl)-5-(arylmethyl)-2-(indol-1(3)-yl)pyrroles and 1-(2-aminomethylphenyl)-2-aryl-(indol-3-yl)-methylpyrroles.

A route towards pyrrolo[2,1-a]isoquinolines through a 3CR of 1-aroyl dihydroisoquinolines, activated alkynes and alcohols has been developed.

An effective strategy for the synthesis of benzo[h]pyrrolo[2,1-a]isoquinoline derivatives has been developed. The process can be described as a one-pot domino reaction that consists of an initial Michael addition, intramolecular cyclization, and subsequent transformations leading to the formation of the desired products. A wide range of structurally diverse hydrogenated benzo[h]pyrrolo[2,1-a]isoquinolines were obtained in 34-98% yield. This strategy represents an efficient catalyst-free procedure that allows the synthesis of previously inaccessible compounds.

A method for the preparation of 4-amino-substituted tetrahydropyrimido[4,5-d]azocines containing an aromatic pyrimidine fragment has been developed. It was established that tetrahydropyrido[4,3-d]pyri-midines are cleaved by the action of activated alkynes with the formation of 6-vinylpyrimidines.

It has been established that the reaction of pyrrolo[1,2-a][1,4]benzodiazepines with activated alkynes gives pyrrolo[1,2-a][1,6]benzodiazonines as the products of diazepine ring expansion. In the case of pyrrolo[1,2-a][1,4]benzodiazepine, substituted with formyl group at the pyrrole ring, both expansion and cleavage of the diazepine fragment can occur.