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Alkylation of substituted 5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinolines with iodomethane, 2-iodopropane, or substituted benzyl halides (R—Hal) afforded quaternary 2-R-5,6-dihydro-1,2,4-triazolo[3,4-a]isoquinolinium salts, for which a possibility of the formation of carbene PEPPSI complexes with palladium(ɪɪ) and pyridine, as well as 2-, 3-, and 4-picolines, was demonstrated.

4-Aryl-2-methylbutan-2-ols with methoxy or methylenedioxy substituents participate in the Graf–Ritter reaction with methyl thiocyanate in the presence of an acid (H2SO4, MeSO3H) forming 1-methylsulfanyl-2-benzazepines in low yields (11–35%), which undergo cyclization with benzhydrazide or hetarenecarboxylic acid hydrazides upon reflux in o-dichlorobenzene into the corresponding 3-phenyl- and 3-hetaryl-6,7-dihydro-5H-1,2,4-triazolo[3,4-a][2]benzazepines (45–74% yields).

(3β,18α,19β)-3-Amino-19,28-epoxy-18α-oleanane and its acetate, which were prepared from allobetulone, were used in the one-pot synthesis of a pyridine imine palladium complex.

Diterpene derivatives of imidazole and benzimidazole were synthesized by the phase-transfer alkylation of imidazole and benzimidazole with a sterically congested diterpene bromoketone. The corresponding imidazolium and benimidazolium salts were also prepared.

Ozonolysis of 3β,28-diacyloxylup-20,29-enes gave 20-oxo-29-nor-3β,28-diacyloxylup-20,29-enes, which were brominated with molecular bromine in AcOH to obtain a mixture of 30-bromo- and 30-dibromo derivatives. Ozonolysis of 30-bromo-3β,28-diacylbetulin produced 29-nor-30-bromoketones, whose reaction with sodium azide afforded 29-nor-30-azidoketones of the lupane series.

The reaction of 30-bromo-3β,28-diacylbetulin with sodium azide afforded 30-azido-3β,28-diacyloxylup-20(29)-enes. The products were subjected to a CuI/TMEDA-catalyzed click reaction with ethynylferrocene to obtain the corresponding ferrocene-betulin conjugates with a 1,2,3-triazole linker.

Complexes of palladium(II) with N-heterocyclic carbenes of the PEPPSI-type were synthesized by the reaction of PdCl2 with 1-adamantyl-3-(R-methyl)-1H-imidazolium salts. These complexes were used as productive precatalysts for substituted thiophene and imidazole arylation by C—H-activation.

Starting from 1-adamantanyl-3-imidazole, a number of new 1-adamantanyl-3-benzylimidazolium salts and corresponding unsymmetrically substituted Pd(II) PEPPSI-type complexes were prepared, including dichloride, dibromide, and diiodide. Single crystal X-ray crystallography confirmed solid state structures in six cases. The complexes reported in this work displayed moderate activities as precatalysts for CH activation/arylation reaction of substituted thiophenes.

The paper presents a method for optical detection drones using the YOLO v4 neural network. Recognition performs simultaneously in the visible (Vis) and long-wave infrared (LWIR) ranges. The results of UAV detection on various types of urban background environment at day and night conditions, as well as at different distances from cameras, are presented. An algorithm for detecting of unmanned vehicles in the video cameras field of view of the Vis and LWIR ranges is described. This algorithm takes as input the outputs of two neural networks that recognize the drone in two ranges and estimates the probability of detection. Its shown that the YOLO v4 neural network recognizes unmanned objects on various background substrates with a minimum temperature difference of 0.4 degrees on the NEC 2640 thermal imager.

Ferrocene conjugates with a lupane triterpenoid linked through a triazole ring and C3 or C6 hydrocarbon tether were synthesized by reaction of ferrocenylalkylazides with betulonic acid propargyl ester. Analogous conjugates were obtained from dehydroabietic acid propargyl ester.

Reactions of 4- and 4′-substituted chalcones with naphthalen-2-amine afforded isomeric benzo[g]- and benzo[f]quinoline derivatives. Depending on the substituent in the initial chalcone, the cyclization follows two pathways through different intermediates. The product structure was confirmed by IR, 1H and 13C NMR, and mass spectra and X-ray analysis.

Successive reactions of vanillin with aromatic aldehydes at the phenol group and ferroceneboronic acid at the carbonyl group catalyzed with various N-heterocyclic carbenes afforded the corresponding ferrocenyl esters. In these reactions copper(II) sulfate, cinnamic aldehyde, and air oxygen act as oxidants. The resulting ferrocenyl esters of vanillic acid were tested for cytotoxicity.

N-Heterocyclic carbene-catalyzed oxidative esterification of ferroceneboronic acid by aromatic and heteroaromatic aldehydes affords the new ferrocenol hetaryl and aryl esters 1 - 4, 6 - 8 and 9 - 11. The reaction takes place under mild conditions. The X-ray crystal structure of ferrocenyl esters 3, 6, 11 was determined.

Ferrocenol esters were prepared by the reaction of ferrocenylboric acid with aldehydes and air oxygen catalyzed by N-heterocyclic carbene. Optical properties (electron absorption and fluorescence spectra) and electrochemical behavior of the obtained compounds were studied (oxidation and reduction during the process of cyclic voltammetry).

Aromatic aldehydes reacted with arylboronic acids under catalysis by N-heterocyclic carbene and oxic conditions to produce phenol esters.

Reactions of propargyl dehydroabietate with ferrocenylalkyl azides led to the formation of substituted 1,2,3-triazoles. The corresponding 1,2,3-triazoles formed in the reaction of ferrocenylalkyl azides with propargyl betulonic ester.

Benzimidazolium salts with an oxo group in the substituent are synthesized from a diterpene ketone.

Products of crotonic condensation of ferrocenecarbaldehyde with allobetulone and betolonic acid methyl ester are described.

Adamantyl-substituted imidazolium salts were synthesized on the basis of abietane derivatives. The products were tested as N-heterocyclic carbene ligands in the palladium-catalyzed Sonogashira reaction.

Two isomeric ferrocenyl chalcones having an abietane fragment were synthesized. Accessibility of various ferrocene derivatives, their high chemical stability, and penetrating ability toward membranes make them promising as substrates for conjugation with biomolecules. In recent time, interest in ferrocene derivatives as alternative drugs for chemotherapy of malignant tumors has increased considerably [1]. Some ferrocene derivatives were found to be active against cervix adenocarcinoma HeLa, melanoma Fem-x, and myelogenous leukemia K562 cell lines [2]. In addition, modifications of drugs used in clinical practice with ferrocenyl fragments were reported [3]. Among other ferrocene derivatives, ferrocenylsubstituted chalcones were synthesized [4]. Ferrocenyl derivatives of diterpenes were described in [5], and chalcones containing a dehydroabietic acid residue were reported in [6]. There are no published data on ferrocenyl chalcones linked to diterpene fragments. In the present communication we describe the synthesis of ferrocenyl chalcones of the abietane series and their cytotoxic activity. By condensation of ferrocenecarbaldehyde (I) with methyl (1R,4aS,10aR)-6-acetyl-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenantrene-1carboxylate (II, 12-acetyldehydroabietic acid methyl ester) [7] according to Claisen–Schmidt (KOH in methanol) we obtained chalcone III in 35% yield (Scheme 1). Pure trans isomer III was isolated by column chromatography on silica gel, followed by recrystallization from methanol. Its configuration followed from the large coupling constant (J ≈ 15 Hz) for the vinylic protons. Isomeric chalcone VI was synthesized in 4% yield from acetylferrocene (IV) and methyl (1R,4aS,10aR)6-formyl-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10aoctahydrophenanthrene-1-carboxylate (V, 12-formyldehydroabietic acid methyl ester) [8]. Aldehyde V was prepared in turn by the Sommelet reaction of 12-chloromethyl derivative VII [9] (Scheme 2). The low yield of VI may be rationalized by steric hindrances created by the isopropyl group to nucleoDOI: 10.1134/S1070428012060152

New chiral benzimidazolium salts were synthesized on the basis of abietane and were used as N-heterocyclic carbene ligands in the Heck reaction.

By the reaction of N-alkyl- and N-arylimidazoles with 30-bromo-3,28-diacetoxylup-20(29)-ene a series was synthesized of unsymmetrically substituted chiral imidazolium bromides with a lupane fragment.

Addition of 1,3,3-trimethyl-3,4-dihydroisoquinolines to N-benzylideneanilines gives substituted N-[2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)-1-phenylethyl]anilines, whereas 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one reacts with N-benzylideneanilines along two pathways involving cyclization to substituted 2,3,3a,4,10,11-hexahydrobenzo[f]pyrrolo[2,3-d]quinolin-5(1H)-ones or elimination of the aniline residue with formation of substituted 5′,5′-trimethyl-2-styryl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-ones.

The reaction of N,N′-carbonyldiimidazole with ethanol and epoxy oligomers of diphenylolpropane diglycidyl ether and 4,4′-bis(glycidylamino)-3,3′-dichlorodiphenylmethane was studied by gas chromatography- mass spectrometry and differential scanning calorimetry. From these oligomers and N,N′-carbonyldiimidazole transformation products, epoxy polymers were synthesized, and their physicomechanical and adhesion properties were determined.

Oxidation of substituted N-acyl-4-phenyl-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolines led to the corresponding 1,2-epoxides and 1,2-diols. The synthesized 1,2-epoxides were characterized with respect to acute toxicity, cytotoxicity, analgesic activity, and influence on locomotion and exploration in an open-field test.

Hydrolytic cleavage of 1-substituted 2-azaspiro[4.5]undeca-1,6,9-trienes in acid medium is accompanied by dienone-phenole rearrangement with formation of substituted N-[2-(p-hydroxyphenyl)ethyl] carboxylic acid amides. 1,2-Dimethoxy-3-oxo-15-phenyl-14-azadispiro[5.1.5.2]pentadeca-1,4,14-triene and 2′-R-7a′-methyl-3a′,4′,5′,6′,7′,7a′-hexahydrospiro[cyclohexa[2,5]diene-1,3′-indol]-4-ones undergo analogous cleavage.

Methyl 12-chloromethyl-dehydroabie-tate reacts with 1-benzyl- and 1-arylimidazoles to give unsymmetrically substituted imidazolium chlorides (1a–i), with abietane moiety. Starting from methyl 12-aminodehydroabietate, symmetrically substituted diterpene-based salts of imidazolinium (4) and imidazolium (5) were synthesized. Anion exchange afforded corresponding (1e·BF4) and (1e·PF6). The new compounds were tested as ligands for a Pd-catalyzed Suzuki-Miyaura reaction. The molecular structure of (1e) is reported. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:5–15, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20745

By reactions of N-alkyl- and N-arylimidazoles with methyl 12-bromoacetyldehydroabietate a series of unsymmetrically substituted chiral imidazolium bromides with the abietane fragment was synthesized. The salts obtained were suggested as new N-heterocyclic carbene ligands in the Suzuki-Miyaura reaction.

Glyoxylate and arylglyoxal imines based on 12-aminodehydroabietic acid undergo hetero-Diels—Alder (Povarov) reaction with ethyl vinyl ether, cyclopentadiene, and indene to give, respectively, methyl (8aR,9R,12aS)-3-aroyl-5-isopropyl–9,12a-dimethyl–7,8,8a,9,10,11,12,12a-octahydronaphtho[1,2-f]quinoline-9-carboxylates, methyl (7R,10aS,10dR,13aS)-1-aroyl–3-isopropyl–7,10a-dimethyl–2,5,6,6a,7,8,9,10,10a,10d,13,13a-dodecahydro-1H-naphtho[1,2-f]cyclopenta[c]quinoline-7-carboxylates, and methyl (6aS,11bS,11eS,15R,15aR)-6-aroyl–4-isopropyl–11e,15-dimethyl–2,5,6,6a,7,11b,11e,12,13,14,15,15a-1H-dodecahydroindeno[2,1-c]-naphtho[1,2-f]quinoline-15-carboxylates.

The methods of synthesis of some new derivatives of abietane including pyridines and indoles fused with diterpene skeleton were described.

A three-component condensation of 1,2,3- or 1,2,4-trimethoxybenzene with isobutyric aldehyde and alkyl cyanoacetates in the presence of sulfuric acid resulted in the formation of substituted 2-azaspiro[4.5]deca-6,9-diene-8-ones. The same reaction of aromatic nitriles yielded 2-azaspiro[4.5]deca-1,6,9-triene-8-ones; in the case of 1,2,3-trimethoxybenzene corresponding Ritter amides were also observed. The condensation of 1,3,5-trimethoxybenzene with isobutyric aldehyde and alkyl cyanoacetates provided the compounds of the formal Knoevenagel condensation.

A series of substituted 5-dialkylaminoacetyl-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolines were synthesized by amination of the corresponding 5-chloroacetyl-3a,4,5,9b-tetrahydro-3H-cyclopenta[c]quinolines. The acute toxicity, analgesic activity, and influence of the obtained compounds on the locomotor and exploratory activity in the open-field test were studied.

Ozonation of N-acyl-4-phenyl-3a,4,5,9b-tetrahydro-3 H-cyclopenta[ c]quinoline gave stable ozonides: a conformationally mobile isomer with the pseudoequatorial N-acyl group and a conformationally stable isomer with the pseudoaxial N-trifluoroacetyl group.

Four-component condensation of 1,3,5-trimethoxybenzene, a C2-synton, and alkyl cyanoacetate in the presence of concentrated sulfuric acid gave the corresponding 1-alkoxycarbonylmethylidene-6,10-dimethoxy-8-[(alkoxycarbonyl)cyanomethylidene]-3,3-R2-2-azaspiro[4.5]deca-6,9-dienes.

Reactions of aromatic Schiff bases with alkenes affording substituted 1,2,3,4-tetrahydroquinolines are reviewed. The synthetic potential and the mechanisms of reactions and the effect of catalysts and solvents on the stereochemistry of products are considered.

A mixture of diastereomeric 3-acetoxy-(2,3),(19β,28)-diepoxyoleananes was prepared via reaction of 3-acetoxy-19β,28-epoxyolean-2-ene with m-chloroperbenzoic acid. Directed rearrangement of these formed 2β-acetoxy-19β,28-epoxyolean-3-one whereas heating of them in amines produced oleanane-type enamines.

1-R-3,3-Dimethyl-2-azaspiro[5.5]undeca-1,7,10-trien-9-ones were synthesized by condensation of 4-(p-methoxyphenyl)-2-methylbutan-2-ol with nitriles RCN in the presence of a concn. sulfuric acid.

A series of 1-aryl-3,3-dimethyl-3,4-dihydroisoquinolines were obtained by three-component (one-pot) condensation of veratrole, isobutylene oxide, and aromatic nitriles and then reduced to the corresponding 1,2,3,4-tetrahydroisoquinolines. Hydrochlorides of the synthesized compounds were tested for anticoagulant activity.

2-(p-hydroxyphenyl)cyclohexylamides were synthesized from ω-chlorocarboxylic acids using the Ritter reaction. Subsequent reduction under the action of LiAlH4 led to the corresponding substituted cyclic amines. The acute toxicity, analgesic properties, and antidepressant activity of the synthesized compounds were studied and their action on locomotion and exploration activity in the open-field test was evaluated.

A series of substituted 1-arylamino-3,4-dihydroisoquinolines have been synthesized using reactions of 1-methylthio-3,3-dimethyl-3,4-dihydroisoquinolines with substituted anilines and 2-aminothiazoles. The products were tested for analgesic and antiinflammatory activity.

A three component “one-pot” condensation of 1,2-ethylenedioxybenzene and RCN nitriles with isobutylene oxide, isobutyraldehyde, or cyclohexanecarboxaldehyde in the presence of conc. H2SO4 gives 1-R-3,3-dialkyl-6,7-ethylenedioxy-3,4-dihydroisoquinolines.

3,3,-Dialkyl-1-cyano-3,4-dihydroisoquinolines were prepared by Beckmann defragmentation of ethyl α-(3,3-dialkyl-3,4-dihydroisoquinol-1-yl)-α-hydroximinoacetates and they take part in a Ritter reaction to form substituted bis-1,1′-(3,4-dihydroisoquinolines).

A series of phencyclidine homologs was synthesized by reductive cyclization of substituted ω-chlorine-substituted l-N-[l-(p-hydroxybenzyl)cyclohexyl]amides with LiAlH4. The synthesized compounds were characterized and tested for neurotropic activity.