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The highly efficient gram-scale method for preparation of up to date hardly available N6-phosphorylated sydnone imines based on the reaction of sydnone imine hydrochlorides with substituted phosphinate or phosphonate acids chlorides in the presence of a base was elaborated. A possibility of straight deprotonation of sydnone imines with n-BuLi followed by the reaction 4-Li-derivatives thus obtained with electrophiles was demonstrated. Novel representatives of bicyclic sydnone imines fused via 4,5-edge of the oxadiazolium ring were obtained. Also sydnone imines containing both phosphorus and sulfur functionalities were obtained with high yields.

A partial reduction of the strained β-pyrrolidino-α,β-unsaturated trifluoromethyl ketones with LiAlH4 gives the corresponding α,β-unsaturated trifluoromethyl ketones. Their interaction with 1-(methyleneamino)pyrrolidine in the presence of Mg(ClO4)2 proceeds through the several intermediate steps to afford trifluoromethylated pyrroles, condensed with substituted cylobutene fragments.

CAN-catalyzed reactions between α-ferrocenyl ethanol or ferrocenyl methanol and S-, N- and O-carborane nucleophiles are reported. This approach is an efficient and simple procedure for the preparation of carborane derivatives containing ferrocenyl units. Energy and geometry optimizations of some carboranylthio-, carboranylamino- and carboranyloxy-substituted ferrocenes have been calculated using the density functional theory. A series of new ferrocene-containing carborane 1,2,3-triazoles have been synthesized in good yields through a facile copper-mediated 1,3-dipolar cycloaddition reactions of alkynyl ferrocenes with [(o-carboran-1-yl)methyl]azide. Molecular structure of carborane-substituted ferrocenyl triazole was established by single crystal X-ray diffraction study. Representative examples of all ferrocenyl carboranes prepared were characterized by IR, 1H and 11B NMR spectroscopy.

9-Substituted 1,2-bis(diphenylphosphanyl)-o-carboranes were synthesized from the corresponding 9-R-o-carboranes (R = I, i-Pr, SMe), and their complexes with chromium, molybdenum, and palladium were obtained. The coordination chemical shifts calculated from the 31P NMR spectra of the complexes and free ligands showed that the substituent at B9 of carborane affects the strength of the ligand-to-metal binding, but the latter is determined to a greater extent by the nature of the metal and its ligand environment.

α-Ferrocenylalkyl carbonates were demonstrated to be the species for ferrocenylalkylation reactions. The α-ferrocenylalkyl carbonates FcCH(R)OCOOEt (1a-c, Fc = ferrocenyl) were easily generated in situ by a reaction of the α-ferrocenyl substituted alcohols FcCH(R)OH (5a-c) with equimolar amounts of n-BuLi followed by EtOCOCl in THF or Et2O at 20 °C. Due to the low thermal stability, carbonates 1a-c readily undergo a heterolytical decay furnishing the α-ferrocenyl carbocations FcCH(R)+ (2a-c) and carbonate anion R’OC(O)O− (3). The last one reversibly loses a molecule of CO2 giving rise anion EtO− that is capable of deprotonating a pre-nucleophile NuH (MeCOCH2COMe, dimethyl malonate, etc.) giving rise the corresponding nucleophile Nu−. The interaction between 2a-c and Nu− produces the α-ferrocenylalkylation products FcCH(R)Nu (4a-c) in moderate to high yields. The sequence above is a novel α-ferrocenylalkylation procedure easily proceeding under mild and neutral conditions. Due to these features, it may be useful for α-ferrocenylalkylations of either thermally labile compounds or the substrates susceptible to acidic conditions. The stability of carbonates 1a-c was found to decrease as the stability of the corresponding carbocations 2a-c increases. With 2-mercapto-1-methylimidazole, the α-ferrocenylalkylations proceed as the N-alkylation processes.

A highly efficient gram-scale method for the C(4)-functionalization of sydnone imine hydrochloride derivatives was developed. This new approach was realized through consecutive reactions including the preparation of a C(3)-substituted N 6 - tert -butoxycarbonyl sydnone imine derivative, deprotonation with n -BuLi and reaction of the lithiated-intermediate with an electrophilic agent, and removal of the Boc protecting group.

An efficient triflic acid catalyzed regioselective alkylation of 5-R-1H-tetrazoles with readily available allylcarboranes is reported. The suggested synthetic procedure allows the formation of a variety of carboranyl-substituted tetrazoles in a good yield under mild conditions. Transformations of newly synthesized carboranyl tetrazoles under UV irradiation were studied. Allylcarboranes as starting materials were prepared via Pd-catalyzed cross-coupling reaction of iodocarboranes with allylmagnesium bromide.

Local piezoelectric and ferroelectric properties as well as morphology of single crystals and films of two novel chiral organic compounds derived from chiral 2-methoxy and 2-amino acids have been investigated. The crystals demonstrated piezoelectric response exceeding that of lithium niobate. The piezoelectric response was registered also in compound films. Piezoelectric properties and domain structure of single crystals and films have been studied by piezoresponse force microscopy.

A preparative method of synthesis of N6-α-haloacyl sydnone imine derivatives has been developed. These compounds are convenient intermediates for the synthesis of a large variety of N6-α-amino-substituted and N6-α-thio-substituted acyl derivatives of sydnone imines. The obtained sydnone imine derivatives may be of interest in the context of searching for new physiologically active compounds.

Friedel-Crafts acylation reaction of ferrocene with carborane carboxylic acid chlorides was shown to be a facile and convenient route for the preparation of carboranyl ferrocenyl oxo-derivatives in high yield. Compounds thus obtained were easily transformed into the corresponding alcohols using lithium aluminum hydride whereas their conversion into the corresponding ferrocenylalkyl carboranes was reached with monochloroalane. Substitution of hydroxyl group in carboranyl ferrocenyl alcohols with S-nucleophile in the presence of CAN as a catalyst was investigated.

Novel neutral and anionic fluorinated carboranylporphyrins for boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) were synthesized by the reaction of 5,10,15,20-pentafluorophenylporphyrin and its copper(II), zinc(II), and palladium(II) complexes with closo-mercaptocarboranes and cesium 1-mercapto-1-carba-closo-dodecaborate. Preliminary evaluation of biological activity reveals that anionic carboranylporphyrins are promising agents for BNCT and PDT.

A novel series of 5-substituted carborane tetrazoles was synthesized by acylation of 5-phenyl-1-H-tetrazole with the available o- and m-carborane carboxylic acid chlorides or o- and m-carborane acetic acid chlorides in the presence of pyridine. Successive thermolysis of the carborane tetrazoles in toluene followed by the extrusion of nitrogen resulted in a series of previously unknown carborane 1,3,4-oxadiazoles in good yield. Using 2,4-dichloroaniline as an example we showed that carborane-substituted 1,3,4-oxadiazoles can be converted into the corresponding 1,2,4-triazoles.

New carborane-containing amidophosphites are synthesized. Their effectiveness as ligands in the Rh-catalyzed hydroformylation of alkenes in supercritical carbon dioxide (SC-CO2) is tested. It is shown that the use of carboranylamidophosphites makes it possible to achieve a high degree of conversion at a low catalyst loading. In the SC-CO2 medium, the regioselectivity is higher as compared to the toluene medium.

The synthesis of 1-[(2-R-o-carboran-1-yl)methyl]benzotriazoles (R = Me, Ph) is described. α-Deprotonation of these compounds followed by reactions of the generated carbanions with MeI give the corresponding α-methylated products. Even at room temperature, they exist in solution as an equilibrium mixture of two conformers due to steric crowding around the Cα atom. In contrast, the anions generated by deprotonation of α-ferrocenyl derivatives of 1-methyl- and 1-ethylbenzotriazoles are ambident and are attacked by electrophiles at both the Cα and N(3) atoms.

ortho-Carborane (1,2-C2B10H12) was found to be a carrier of protons in both mitochondrial and artificial lipid membranes, suggesting that this dicarborane can reversibly release hydrogen ions and diffuse through the membranes in neutral and anionic forms. Similar to conventional uncouplers (e.g. 2,4-dinitrophenol), o-carborane stimulated mitochondrial respiration and decreased the membrane potential at concentrations of tens of micromoles. Protonophoric activity of o-carborane was observed both by a fluorometric assay using pyranine-loaded liposomes and electrical current measurements across planar lipid bilayers. Substantial contribution of the proton flux to the o-carborane-mediated current was proved by a shift of the zero current voltage upon imposing a pH gradient across the membrane. Meta-carborane (1,7-C2B10H12) lacked the protonophoric activity in line with its reduced C–H acidity. The results suggest that weak C–H acids can exhibit protonophoric activity in the biological environment. The finding of a new class of protonophoric compounds is of substantial interest due to promising anti-obesity and anti-diabetic properties of uncouplers.

Boronated derivatives of porphyrins are studied extensively as promising compounds for boron-neutron capture therapy and photodynamic therapy. Understanding of the mechanism of their permeation across cell membranes is a key step in screening for the most efficient compounds. In the present work, we studied the ability of boronated derivatives of chlorin e 6 and porphyrins, which are mono-, di-, and tetra-anions, to permeate through planar bilayer lipid membranes (BLM). The translocation rate constants through the hydrophobic part of the lipid bilayer were estimated for monocarborane and its conjugate with chlorin e 6 by the method of electrical current relaxation. They were similar, 6.6 and 6.8 sec−1, respectively. Conjugates of porphyrins carrying two and four carborane groups were shown to permeate efficiently through a BLM although they carry two charges and four charges, respectively. The rate of permeation of the tetraanion estimated by the BLM current had superlinear dependence on the BLM voltage. Because the resting potential of most mammalian cells is negative inside, it can be concluded that the presence of negatively-charged boronated groups in compounds should hinder the accumulation of the porphyrins in cells.

1,2-Bis(azidomethyl)-о-carborane and 1,7-bis(azidomethyl)-m-carborane, prepared from the corresponding carboranylmethyl triflates and sodium azide, were conveniently functionalized by azide–alkyne cycloaddition affording novel bis[(1,2,3-triazolyl)methyl]carborane derivatives. Regiospecificity of this process was achieved by employing copper(II) acetate hydrate. Reaction of bis[(1,2,3-triazolyl)methyl]carborane derivatives with MeI yielded 3-methyl-1,2,3-triazolium carborane salts.

Allyl amination and alkylation catalyzed by a palladium complex-phosphite-type-ligand catalyst in a supercritical carbon dioxide (SC-CO2) medium is studied. It is demonstrated that that the Pd-containing catalysts dissolved in SC-CO2 provide a high regioselectivity of the reaction and, thus, offer a convenient method for synthesizing allylamines.

The reactions of 3,6-disubstituted and azoloannulated 1,2,4,5-tetrazines containing heterocyclic leaving groups with S-nucleophiles were studied. The methods of introduction of functionalized thiols, including thiol derivatives of 1,7- and 1,2-dicarba-closo-dodecaboranes, into the tetrazine ring were developed. It was established for the first time that, instead of replacement of a leaving group in the tetrazine ring, the attack of S-nucleophile at the unsubstituted carbon atom occurs in the case of imidazo[1,2-b][1,2,4,5]tetrazines to form previously unknown products of nucleophilic substitution of the hydrogen atom.

The influence of amphiphilic polymers polyvinylpyrrolidone, poly(ethylene oxide), poly(vinyl alcohol), and pluronic F127 (propylene oxide-ethylene oxide triblock copolymer) on the catalytic activity of a number of water-soluble metal-free porphyrin photosensitizers was studied in the reaction of tryptophan photooxidation in aqueous solution. The introduction of the specified polymers was found to enhance the activity of carbon-substituted tetrafluorophenylporpyrin, photoditazine, and dimegin. It was ascertained that introduction of polyvinylpyrrolidone had the strongest effect on the increase in the photooxidation process rate; the change in the activity of porphyrins was 30–70%. The introduction of poly(ethylene oxide), poly(vinyl alcohol), and pluronic F127 was shown to enhance the rate of the process by 10–40%. It was concluded that this polymer effect was connected with the dissociation of aggregates, in which form porphyrin molecules were present in aqueous solutions, as indicated by an increase in fluorescence intensity of porphyrins. The introduction of polymers resulted in a bathochromic shift of the fluorescence bands for all porphyrins, which accounted for the formation of complexes of porphyrin sensitizers with the polymers.

New chiral carboranylamidophosphite ligand was synthesized and tested in the Rh-catalyzed asymmetric hydrogenation of α- and β-dehydroamino acid derivatives (up to 93% ee). The catalytic performance is affected greatly by temperature and the nature of solvents. Importantly, we have shown that in the hydrogenation of the β-dehydroamino acid derivatives the use of acidic 1,1,1,3,3,3-hexafluoro-2-propanol led to a significant increase in the enantioselectivity, compared to isopropyl alcohol.

An improved method for the synthesis of 8-[(1E)-2-phenylethenyl]codeinone dimethyl ketal was described. The ability of [(1E)-2-phenylethenyl] substituent to stabilize effectively the π-system of the ring C is responsible for the essential difference in both the reactivity and the compositions of products formed in the reactions of the corresponding substituted and unsubstituted codeinone and thebaine derivatives.

Photodynamic therapy is a way of selective destruc� tion of malignant tumors through the formation of free oxygen species upon the action of monochromatic light on the cells that contain a photosensitizer (PS) [1–3]. Of considerable interest are PS based on natu� ral chlorophyll a due to their low dark toxicity and the ability to be predominantly accumulated in tumors [4]. These compounds show intense red absorption (λ = 650–720 nm), which enables treatment of deeply located tumors. Previously we synthesized boronated porphyrin and chlorin derivatives and showed that boronation is an important factor increasing the antitumor effi� ciency of tetrapyrrole compounds [5, 6]. This paper reports the synthesis of previously unknown boronated derivatives of purpurin�18 and spectrophotometric studies of binding of new com� pounds to the human serum albumin (HSA), a trans� porter of PS molecules in the body [7–9]. The reac� † Deceased. tions of PS with proteins can enhance the therapeutic effect as a result of decrease in the PS toxicity and increase in the yield of its triplet state. Thus, study of PS binding to HSA is an important stage in the devel� opment of new effective PS. Purpurin�18 ( I), which was used for the synthesis of boronated derivatives, was prepared by oxidative cleavage of methyl pheophorbide a by KOH in the presence of air oxygen [10]. The presence in I of a six� membered anhydride ring containing two carbonyl groups extends the tetrapyrrole chain of conjugation, which is manifested as a bathochromic shift of the

Asymmetric hydrogenation of (E)-dimethyl-2-acetamido-2-phenylvinylphosphonate was performed in CH2Cl2 and supercritical carbon dioxide with the participation of Rh and Ir complexes with chiral phosphite-type ligands. Iridium catalysts dissolved in supercritical CO2 allow high enantioselectivity (up to 98.5% ee) and conversion to be obtained. Rhodium catalysts yield exclusively racemic reaction products.

α,β-Unsaturated trifluoromethylketones of cyclobutene number containing trimethylstannyl substituent in β-position were firstly prepared by the addition of trimethylstannyllithium to the corresponding trifluoromethylenaminoketones. The protection of carbonyl function under basic conditions conserving the organometallic substituent was elaborated. The generation of corresponding organolithiums by Sn–Li exchange and their reactivity was studied.

New chiral carborane-containing amidophosphites containing the BINOL fragment (BINOL stands for 2,2′-dihydroxy-1,1′-binaphthyl) have been synthesized. The study of efficiency of these compounds as ligands in the Rh-catalyzed asymmetric hydrogenation of enamides in supercritical carbon dioxide (scCO2) and CH2Cl2 showed that enantioselectivity of the process is considerably higher in scCO2.

This paper examines the modification of zeolites with superstoichiometric amounts of metals using multistep cluster synthesis. Ion-exchange sites in zeolite MFI-50 (SiO2/Al2O3 molar ratio of 50) have been modified with hydrazonium cations. Subsequent redox reaction with chromate anions has yielded a chromium-containing zeolite. The sample prepared by three ion-exchange/redox cycles contains 10 wt % chromium (Cr-MFI-50). EPR results show that most of the chromium in Cr-MFI-50 is in the form of fine Cr2O3 particles. In addition, the material contains isolated Cr5+ ions and, presumably, Cr3+ stabilized at aluminum vacancies.

Pd-catalyzed amination of allylic carbonates with N -( ortho -carboran-3-yl)- N -methylamine was carried out in supercritical CO 2 . It has been demonstrated that complete conversion of allylic carbonates to the corresponding carborane amines with excellent regioselectivity may be achieved in scCO 2 (170 atm, 60 °C) using NaHCO 3 as the acceptor base. The reaction offers a selective method for the preparation of allylic amines and provides a useful approach to new terpenoids.

A general approach has been proposed for incorporating high concentrations of modifier metals into high-silica zeolites. MFI zeolites have been modified with mono- and polymetallic sulfide clusters of copper, manganese, zinc, cobalt, and nickel. The metal incorporation sequence and the nature of the anion have been shown to influence both the total content and the ratio of the modifiers in the zeolite. Using multistep syntheses, we have prepared zeolites containing superstoichiometric amounts of modifier metals. Using a variety of physicochemical characterization techniques, the zinc-containing sample has been shown to have a uniform modifier distribution. The Cu-MFI-50 and Mn-MFI-50 zeolites have been characterized by electron paramagnetic resonance and shown to contain isolated Cu2+ and Mn2+ ions stabilized on the aluminum lattice site.

This paper describes a novel synthetic approach to 2-cyano-3-trifluoromethylthiophenes fused with cyclobutene rings with variable spiro conjunctions. The reaction of substituted 1-bromo-2-trifluoroacetylcyclobutenes with mercaptoacetonitrile results in the substitution of bromine with S-center to afford the corresponding nitriles in high yields, which form the target thiophenes by subsequent treatment of lithium 2,2,6,6-tetramethylpiperidide and acetic anhydride.

The regioselective reduction of substituted 1-bromo-2-trifluoroacetylcyclobutenes by lithium aluminium hydride affords corresponding brominated alcohols, which, under the treatment of two equivalents of butyllithium, give new lithiated cyclobutenes. Their carboxylation followed by lactonization induced by trifluoroacetic anhydride appeared to be an effective approach towards 5-trifluoromethylated furanones condensed with substituted cyclobutene rings.

A reaction of tetrahydropyridines, obtained by the Diels-Alder reaction from α,β-unsat-urated N,N-dimethylhydrazones and methyl acrylate, with acetylenes activated with the trifluoroacetyl group has been studied and found to lead to polysubstituted trifluoroacylated tetrahydroazocines. No cyclobutene intermediates have been detected.

The highly reactive trifluoromethylenaminoketones, with a strained cyclobutene and norbornadiene moieties were firstly prepared from the corresponding β-halogeno-α,β-unsaturated trifluoromethylketones in almost quantitative yields. The ambident properties of these compounds in the reactions with organolithiums were discovered. The simple methods to control the selectivity of 1,2- or 1,4-addition of lithiated nucleophiles have been investigated.

The [4+2] cycloaddition reactions of 3,6-disubstituted 1,2,4,5-tetrazines with 9-allyl-1,7-,9-allyl-1,2-dicarba-closo-dodecaboranes and 1-allyl-2-isopropyl-1,2-dicarba-closo-dodecab-orane have been studied. The pyridazines containing carborane cage have been synthesized for the first time.

New routes to closo-carboranyl derivatives of L-lysine and L-glutamic acid with free gA-NH2 groups were proposed.

The procedure for the synthesis of 4-formylsydnonimine derivatives based on the reaction of 4-lithiosydnonimines with (methoxymethylidene)dimethylammonium methyl sulfate was proposed.

The reactions of 4-chloro-1,1,1-trifluorobut-3-yn-2-one and 4-bromo-1,1,1-trifluorobut-3-yn-2-one with conjugated dienes afford [4+2] cycloadducts in high yields. The halogen atom in the products is readily replaced by a (het)aryl residue in the cross-coupling with organozinc compounds.

When rac- or meso-1,2-bis(tert-butylchlorophosphino)-1,2-dicarba-closo-dodecaborane(12) (1a or 1b) is reacted with [M(CO)4(NBD)] (M = Cr, Mo, NBD = norbornadiene), [Mo(CO)4(EtCN)2] or [W(CO)6], rac-[Cr(CO)4{1,2-(PtBuCl)2C2B10H10}] (2), rac- or meso-[Mo(CO)4{1,2-(PtBuCl)2C2B10H10}] (3a or 3b) and rac-[W(CO)4{1,2-(PtBuCl)2C2B10H10}] (4) could be isolated as pure diastereomers. UV irradiation of 1 with [Cr(CO)6] in moist THF proceeds with hydrolysis and formation of [Cr(CO)4{1,2-(P(OH)tBu)2C2B10H10}] (5) which contains the metal complex-stabilized phosphinous acid. Compounds 2–5 were characterized spectroscopically (1H, 31P, 11B, 13C NMR), by mass spectrometry and by X-ray structure determination.

Halogenated trifluoroacetylacetylenes have been synthesized for the first time. It was shown that they undergo formally forbidden by the orbital-symmetry rules [2+2] cycloaddition reactions with nonactivated alkenes in the absence of light and catalyst. A possible mechanism for this transformation is suggested.

Various structural modifications of chlorins are aimed at optimization of biomedical characteristics of these plant-derived tetrapyrrolic compounds. In particular, conjugation with boron polyhedra improves the efficacy of chlorin e 6 derivatives as antitumor photosensitizers. To obtain the compounds that may possess several clinically favorable characteristics, we synthesized a series of metal chlorin e 6 conjugates with 1-carba- closo -dodecaborate anion that contain Pd(II), Sn(IV) or Zn(II) in the coordination sphere of the chlorin macrocycle. The compounds were synthesized by alkylation of amino group in chlorin e 6 metal complexes with 1-trifluoromethanesulfonylmethyl-1-carba- closo -dodecaborate cesium. The water soluble Pd(II) complex of chlorin e 6 13(1)- N -{2-[ N -(1-carba- closo -dodecaboran-1-yl)methyl]aminoethyl}amide-15(2), 17(3)-dimethyl ester (compound 6 ) evoked low dark cytotoxicity; in striking contrast, 6 potently sensitized human tumor cells to illumination with monochromatic red light. Confocal microscopic studies demonstrated that photoactivation of 6 rapidly (within minutes) changed the patterns of intracellular drug distribution from diffuse cytoplasmic to clustered perinuclear. Co-localization experiments revealed that 6 associated with lysosomes in illuminated cells. These events were paralleled by alteration of mitochondrial shape, a decrease of mitochondrial transmembrane electric potential and the loss of plasma membrane impermeability for propidium iodide, the latter being a hallmark of cell necrosis. Similar mechanisms of cell photodamage were found for structurally close Pd(II) complex of chlorin with neutral carborane and for Sn(IV) chlorin conjugated with the anionic carborane. Thus, metal complexes of carboranylchlorins are efficient photosensitizers capable of triggering rapid necrosis. These compounds are promising for further development as multipotent agents in which each moiety, i.e., metal, the chlorin macrocycle and the boron substituent, as well as the entire complex, can be useful in cancer diagnostics and treatment.

The structure, stability, and potential existence of chromium complexes with triallylborane B(CH2—CH=CH2)3 and its analogs with coordination of the Cr atom to three double bonds are discussed. Complexes LCr(CO)3 are studied where L = (C3H5)3CH, (C3H5)3B, (C3H5)3BNMe3, [(C3H5)3BF]−, (C2H4)3, C6H6, (C3H5)3CPh, (C3H5)3B(NC5H5). The calculations are carried out in DFT terms in approximations PBE/3z and BP86/TZ2P. The calculated dissociation energies of the studied complexes into the fragments Cr(CO)3 and L range from 48.3 to 63.0 kcal mol−1 (BP86/TZ2P) and from 54.2 to 66.9 kcal mol−1 (PBE/3z). Ligands (C3H5)3ER (ER = CPh, B(NC5H5)) can form two isomeric complexes A and B due to coordination of tricarbonylchromium to either three double bonds or benzene or pyridine ring. In the former case, isomer A is less stable as compared to isomer B, while in the latter case isomer Ais more stable. The possibility of selective synthesis of one of these isomers, namely, tris(η2-allyl)pyridineborane complex, is predicted.