Metal (M = Cr, Mo, W, Re) carbonyl complexes with porphyrin and carborane isocyanide ligands: light-induced oxidation and carbon oxide release for antitumor efficacy.

The tetrapyrrolic macrocycle as a scaffold for various chemical modifications provides broad opportunities for the preparation of complex multifunctional conjugates suitable for binary antitumor therapies. Typically, illumination with monochromatic light triggers the photochemical generation of reactive oxygen species (ROS) (photodynamic effect). However, more therapeutically valuable effects can be achieved upon photoactivation of tetrapyrrole derivatives.

Synthesis of new representatives of AB-type carboranylporphyrins based on -tetra(pentafluorophenyl)porphyrin transformations.

A carboranylporphyrin of AB-type bearing a single pentafluorophenyl ring was prepared through the regioselective nucleophilic aromatic substitution reaction of the -fluorine atoms in 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin with 9-mercapto--carborane. The reaction of this porphyrin with sodium azide led to the selective substitution of the -fluorine atom in the pentafluorophenyl substituent with an azide functionality which upon reduction with SnCl resulted in the formation of the corresponding porphyrin with an amino group. Pentafluorophenyl-substituted AB-porphyrins were studied and transformed to thiol and amino-substituted compounds allowing for the preparation of porphyrins with different reactive groups such as hydroxy and amino derivatives capable for further functionalization and conjugation of these porphyrins to other substrates.

BODIPY derivatives modified with carborane clusters: synthesis, characterization and DFT studies.

An efficient approach for the preparation of 3,5-dicarborane-substituted BODIPY conjugates was developed the functionalization of 3,5-dibromo-8-pentafluorophenyl-BODIPY with neutral and anionic carborane -nucleophiles. It was found that 3,5-dicarborane-substituted BODIPYs could be easily modified with a third carborane cluster using SAr substitution reactions of the -fluorine atom in the -pentafluorophenyl BODIPY substituent with the corresponding carborane -nucleophile affording boron-enriched BODIPYs in good yields. The influence of bromine atom substitution with carborane moieties on the position of absorption and fluorescence bands and the fluorescence quantum yields of the prepared BODIPYs were analyzed.

Synthesis, Characterization and DFT Study of a New Family of High-Energy Compounds Based on -Triazine, Carborane and Tetrazoles.

An efficient one-pot synthesis of carborane-containing high-energy compounds was developed via the exploration of carbon-halogen bond functionalization strategies in commercially available 2,4,6-trichloro-1,3,5-triazine. The synthetic pathway first included the substitution of two chlorine atoms in -triazine with 5-R-tetrazoles (R = H, Me, Et) units to form disubstituted tetrazolyl 1,3,5-triazines followed by the sequential substitution of the remaining chlorine atom in 1,3,5-triazine with carborane N- or S-nucleophiles. All new compounds were characterized by IR- and NMR spectroscopy.

Multicomponent Molecular Systems Based on Porphyrins, 1,3,5-Triazine and Carboranes: Synthesis and Characterization.

2,4,6-Trichloro-1,3,5-triazine (cyanuric chloride) is an excellent coupling reagent for the preparation of highly structured multifunctional molecules. Three component systems based on porphyrin, cyanuric chloride and carborane clusters were prepared by a one-pot stepwise amination of cyanuric chloride with 5-(4-aminophenyl)-10,15,20-triphenylporphyrin, followed by replacement of the remaining chlorine atoms with carborane - or -nucleophiles. Some variants of 1,3,5-triazine derivatives containing porphyrin, carborane and residues of biologically active compounds such as maleimide, glycine methyl ester as well as thioglycolic acid, mercaptoethanol and hexafluoroisopropanol were also prepared.

Mechanochemistry for the synthesis of non-classical -metalated palladium(II) pincer complexes.

The peculiarities of cyclopalladation of a series of non-classical pincer-type ligands based on monothiooxalyl amides bearing ancillary N- or S-donor groups in the amide units have been scrutinized both under conditions of conventional solution-based synthesis and in the absence of a solvent according to a solid-phase methodology including mechanochemical activation. Grinding the functionalized monothiooxamides with PdCl(NCPh) in a mortar or vibration ball mill is shown to serve as an efficient and green alternative to the synthesis of these complex metal-organic systems in solution that can offer such advantages as the absence of any auxiliary and significant rate and yield enhancement, especially for the challenging ligands. The realization of S,N,N- or S,N,S-monoanionic tridentate coordination in the resulting pincer complexes has been confirmed by multinuclear NMR (including 2D NMR) and IR spectroscopy and, in some cases, X-ray diffraction.

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization.

Maleimide-containing fluorinated porphyrins and chlorins were prepared based on the reaction of Zn(II) or Ni(II) complexes of 5,10,15,20-tetrakis(4-amino-2,3,5,6-tetrafluorophenyl)porphyrin and chlorin with maleic anhydride. Porphyrin maleimide derivatives were also prepared by the reaction of 5,10,15,20-tetrakis(4-azido-2,3,5,6-tetrafluorophenyl)porphyrinato Zn(II) or Ni(II) with -propargylmaleimide via the CuAAC click reaction to afford fluorinated porphyrin-triazole-maleimide conjugates. New maleimide derivatives were isolated in reasonable yields and identified by UV-vis, H NMR, F NMR spectroscopy and mass-spectrometry.

Cyclotetrasiloxanetetrols with methyl groups at silicon: isomers all-cis- and cis-trans-cis-[MeSi(O)OH](4).

1,3,5,7-Tetramethyl-1,3,5,7-tetrahydroxycyclotetrasiloxane has been synthesized in good yield from tetrapotassium tetramethylcyclotetrasiloxanolate. Methods for isolation of all-cis-isomer I and cis-trans-cis-isomer II as the only crystalline product have been developed. Both isomers have been characterized by single-crystal X-ray diffraction analysis (XRD), elemental analysis, NMR ((1)H, (13)C, (29)Si), and IR.

Boronated protohaemins: synthesis and in vivo antitumour efficacy.

The conjugates of porphyrin macrocycles with boron-containing polyhedra are under investigation as agents for binary treatment strategies of cancer. Aiming at the design of photoactive compounds with low-to-zero dark toxicity, we synthesized a series of carboranyl and monocarbon-carboranyl derivatives of protohaemin IX using the activation of porphyrin carboxylic groups with di-tert-butyl pyrocarbonate or pivaloyl chloride. The water-soluble 1,3,5,8-tetramethyl-2,4-divinyl-6(7)-[2'-(closo-monocarbon-carborane-1''-yl)methoxycarbonylethyl]-7(6)-(2'-carboxyethyl)porphyrin Fe(III) (compound 9) exerted no discernible cytotoxicity for cultured mammalian cells, nor did it cause general toxicity in rats.

Novel boronated derivatives of 5,10,15,20-tetraphenylporphyrin: synthesis and toxicity for drug-resistant tumor cells.

We have developed the synthesis of boronated porphyrins for potential application in cancer treatment, based on the functional derivatives of 5,10,15,20-tetraphenylporphyrin. Boronated amide derivatives starting from 5,10,15,20-tetra(p-aminophenyl)porphyrin and 9-o- and 9-m-carborane carboxylic acid chlorides were prepared. Also, the reaction of 2-formyl-5,10,15,20-tetraphenylporphyrin with closo-C-lithium-o- and m-carboranes, as well as with closo-C-lithium monocarbon carborane, yielded neutral and anionic boronated hydroxy derivatives of 5,10,15,20-tetraphenylporphyrin, respectively.