A simple and efficient method for the synthesis of solutions of high-purity hydrogen trioxide (HOOOH), released in the low-temperature methyltrioxorhenium(VII)-catalyzed transformation of the ozonized polystyrene-supported dimethylphenylsilane, is reported. High-purity hydrogen trioxide solutions in diethyl ether, separated from the polymer, and free of any reactants and by-products, can be stored at ‒20 degree Celsius for weeks. By removing the solvent in vacuo, HOOOH could be isolated in a highly pure form or transferred to other solvents, thus significantly extending the research perspectives of HOOOH for novel applications. The article was selected as “Hot Paper” and featured on the outside cover of the printed journal Angewandte Chemie, 2015, Vol. 54(34). This work was selected among 10 most important research achievements of the University of Ljubljana in year 2015.
COBISS.SI-ID: 1536385475
This paper reports the first examples of osmium complexes with chelating pyridyltriazolylidenes. Furthermore, this is the first example where electronic effects of the substitution patterns on a triazolylidene ligand are systematically investigated for their spectroscopic signature and catalytic properties. These complexes are very efficient precatalyst for the reduction of several carbonyls under transfer hydrogen conditions. A TON of around 10.000 were reached in selected cases. Studying the mechanism, we could confirm the presence of hydride species, which are believed to be the true active catalysts in transfer hydrogenation catalysis. The article was featured on the inside cover of the printed journal Chem. Eur. J. 2015, 21 (http://onlinelibrary.wiley.com/doi/10.1002/chem.201590075/epdf).
COBISS.SI-ID: 1536240835
We have developed the first transformation of chiral β-amino acids into the corresponding β’-hydroxy-β-amino acid derivatives. The method utilizes principles of Evans aldol reaction and enables an independent synthesis of both the α,β-syn and the α,β-anti isomers separately, in stereochemically pure form and in excellent yields. The methodology is mild and robust, readily affording β’-hydroxy-β-amino acid derivatives that were previously inaccessible. This scaffold is of prime importance in the chemistry of β-amino acids, the corresponding peptides, β-aminolactones, and β-lactams. In the context of β-lactams a unified access to β′-hydroxy-β-amino acid derivatives is increasingly important for SAR studies in a search for new lead antibiotics, superior to thienamycin and other potent carbapenams, carbapenems, and carbacephems. The article was highlighted on HighBeam Research portal (https://www.highbeam.com/doc/1G1-408000548.html). This methodology is being used for a stereocontrolled, more than 20-step synthesis of some β-lactams that are of interest of pharmaceutical company Sandoz Austria.
COBISS.SI-ID: 1536171203
We studied the coordination abilities of 1,3-diaryltriazenes to ruthenium(II) and prepared novel ruthenium(II)-p-cymene 1,3-diaryltriazenide complexes as potential anti-cancer drugs. Antiproliferative activity of the resulting compounds was studied against several human carcinoma cell lines and drug-resistant sublines. These were found to possess a remarkable cytotoxic activity against human carcinoma cells with IC50 values generally in sub micro-molar range. Notably, an up to 560-times higher activity was recorded in comparison to the parent non-coordinated 1,3-diaryltriazenes. We also presented a preliminary insight into the molecular mechanism involved in the cytotoxicity of the investigated compounds. This work is the first report on biological properties of ruthenium-triazenide complexes.
COBISS.SI-ID: 1536509635
We have reported on new iridium(III) complexes with chelating “click”-derived 1,2,3-triazoles and 1,2,3-triazolylidenes. This is the first report of a complex where a monomethylated triazol-triazolylidene N/C-donor is bound to only one metal centre in a chelating fashion. The complexes were tested towards their catalytic activity in the direct oxidation of cyclooctane. We were able to produce cyclooctanone in high yields, using mild conditions, at room temperature, and low catalyst loadings (1 mol%). According to the Web of Science, for 2015 the paper was ranked as »Highly Cited Paper«. As of September/October 2015, this highly cited paper received enough citations to place it in the top 1% of its academic field based on a highly cited threshold for the field and publication year.
COBISS.SI-ID: 1536057027