Search
prof. dr hab. inż. Janusz Rachoń
Employment
- Specjalista - doradca at Biuro Praw,Wartości Akademickich i Równego Traktowania
Publications
Filters
total: 82
Catalog Publications
Year 2024
-
Convenient and efficient N-methylation of secondary amines under solvent-free ball milling conditions
PublicationIn the present work, we report the development of a rapid, efcient, and solvent-free procedure for the N-methylation of secondary amines under mechanochemical conditions. After optimization of the milling parameters, a vibrational ball mill was used to synthesize 26 tertiary N-methylated amine derivatives in a short time of 20 min (30 Hz frequency) and high yields ranging from 78 to 95%. An exception was compounds having a hydroxyl...
-
Development of potent and effective SARS-CoV-2 main protease inhibitors based on maleimide analogs for the potential treatment of COVID-19
PublicationIn the present work, we report a new series of potent SARS-CoV-2 Main Protease (Mpro) inhibitors based on maleimide derivatives. The inhibitory activities were tested in an enzymatic assay using recombinant Mpro (3CL Protease from coronavirus SARS-CoV-2). Within the set of new Mpro inhibitors, 6e demonstrated the highest activity in the enzymatic assay with an IC50 value of 8.52 ± 0.44 mM. The IC50 value for Nirmatrelvir (PF-07321332,...
Year 2022
-
Development of Sulfamoylated 4‑(1-Phenyl‑1H‑1,2,3-triazol-4-yl)phenol Derivatives as Potent Steroid Sulfatase Inhibitors for Efficient Treatment of Breast Cancer
PublicationWe present here the advances achieved in the development of new sulfamoylated 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives as potent steroid sulfatase (STS) inhibitors for the treatment of breast cancer. Prompted by promising biological results and in silico analysis, the initial series of similar compounds were extended, appending a variety of m-substituents at the outer phenyl ring. The inhibition profiles of the newly...
Year 2021
-
Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
PublicationBackground: Although Mycophenolic Acid (MPA) is applied as prodrugs in clinic as an immunosuppressant, it also possesses anticancer activity. MPA acts as Inosine-5’-Monophosphate Dehydrogenase (IMPDH) inhibitor, where the carboxylic group at the end of the side chain interacts with Ser 276 of the enzyme via hydrogen bonds. Therefore, MPA derivatives with other polar groups indicated high inhibition too. On the other hand, potent...
-
New potent steroid sulphatase inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives
PublicationIn the present work, we report a new class of potent steroid sulphatase (STS) inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives. Within the set of new STS inhibitors, 6-(1-(1,2,3-trifluorophenyl)-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate 3L demonstrated the highest activity in the enzymatic assay inhibiting the STS activity to 7.98% at 0.5 µM concentration. Furthermore, to verify...
-
Novel 1,2,3-Triazole Derivatives as Mimics of Steroidal System—Synthesis, Crystal Structures Determination, Hirshfeld Surfaces Analysis and Molecular Docking
PublicationHerein, we present the synthesis and crystal structures determination of five 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives containing halogen atoms, 6a–e, which may be used as an excellent mimic of steroids in the drug development process. Good quality crystals obtained for all of the synthesized compounds allowed the analysis of their molecular structures. Subsequently, the determined crystal structures were used to calculate...
Year 2020
-
Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
PublicationMycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including derivatives of tuftsin to modify its immunosuppressive properties. Both amino acid unit in the case of simple MPA amides and modifications within peptide moiety of MPA - tuftsin conjugates influenced the observed activity. Antiproliferative potential of the obtained conjugates was investigated in vitro and MPA amides with threonine methyl...
-
Modifications at the C(5) position of pyrimidine nucleosides
PublicationThis review summarizes the state of knowledge on the chemical methods of C(5)-modifications of uridine and cytidine derivatives and may serve as a useful tool for synthetic chemists to choose an appropriate reaction protocol. The synthesis of 5-substituted uracil derivatives is gaining an increasing interest because of their possible applications in medicine and pharmacy. Modifications at the C(5) position of pyrimidine nucleosides...
-
Novel 1,2,4-Oxadiazole Derivatives in Drug Discovery
PublicationAbstract: Five-membered 1,2,4-oxadiazole heterocyclic ring has received considerable attention because of its unique bioisosteric properties and an unusually wide spectrum of biological activities. Thus, it is a perfect framework for the novel drug development. After a century since the 1,2,4-oxadiazole have been discovered, the uncommon potential attracted medicinal chemists’ attention, leading to the discovery of a few presently...
-
Recent progress in the development of steroid sulfatase inhibitors – examples of the novel and most promising compounds from the last decade
PublicationThe purpose of this review article is to provide an overview of recent achievements in the synthesis of novel steroid sulfatase (STS) inhibitors. STS is a crucial enzyme in the biosynthesis of active hormones (including estrogens and androgens) and, therefore, represents an extremely attractive molecular target for the development of hormone-dependent cancer therapies. The inhibition of STS may effectively reduce the availability...
Year 2019
-
New potent STS inhibitors based on fluorinated 4-(1-phenyl-1H-[1,2,3]triazol-4-yl)-phenyl sulfamates
PublicationA series of fluorinated analogs based on the frameworks of 4-(1- phenyl-1H-[1,2,3]triazol-4-yl)-phenyl sulfamates have been synthesized as steroid sulfatase (STS) inhibitors. The design of chemical structures of new potential STS inhibitors was supported by molecular docking techniques to identify potential interactions between inhibitors and amino acid residues located in the STS active site. The STS inhibitory potency was evaluated...
-
Novel steroid sulfatase inhibitors based on N ‐thiophosphorylated 3‐(4‐aminophenyl)‐coumarin‐7‐O‐sulfamates
PublicationIn the present work, we described convenient methods for the synthesis ofN-thiophosphorylated 3-(4-aminophenyl)-coumarin-7-O-sulfamates as steroid sulfatase(STS) inhibitors. To design the structures of the potential STS inhibitors, molecularmodeling techniques were used. A computational docking method was used to deter-mine the binding modes of the synthesized inhibitors as well as to identify potentialinteractions between specified...
Year 2018
-
Selected Methods for the Chemical Phosphorylation and Thiophosphorylation of Phenols
PublicationThis Focus Review gathers together a selection of methods for the chemical phosphorylation of phenols that employ three‐ and four‐coordinate phosphorus compounds. Phosphorylated scaffolds can exhibit enhanced properties compared to their non‐phosphorylated analogues, such as increased biological activity and increased/decreased solubility; as such, phosphorus compounds have gained more and more interest in organic and medicinal...
-
Synthesis and antimicrobial activity of amino acid and peptide derivatives of mycophenolic acid
PublicationThe series of 16 novel amino acid and peptide mycophenolic acid (MPA) derivatives was obtained as potential antibacterial agents. Coupling of MPA with respective amines was optimized with condensing reagents such as EDCI/DMAP and T3P/TEA. Amino acid analogs were received both as methyl esters and also with the free carboxylic group. The biological activity of the products was tested on five references bacterial strains: Klebsiella...
-
The synthesis and structure of a potential immunosuppressant: N-mycophenoyl malonic acid dimethyl ester
PublicationThe synthesis of a potential immunosuppressant, i.e. dimethyl ester of N-mycophenoyl malonic acid was optimized in the reaction of mycophenolic acid (MPA) with amino malonic dimethyl ester in the presence of propanephosphonic anhydride (T3P) as a coupling reagent. The structural properties of the obtained MPA derivative were investigated by NMR, MS and single crystal X-ray diffraction methods. Theoretical considerations of conformational...
Year 2017
-
Geometry optimization of steroid sulfatase inhibitors - the influence on the free binding energy with STS
PublicationIn the paper we review the application of two techniques (molecular mechanics and quantum mechanics) to study the influence of geometry optimization of the steroid sulfatase inhibitors on the values of descriptors coded their chemical structure and their free binding energy with the STS protein. We selected 22 STS-inhibitors and compared their structures optimized with MM+, PM7 and DFT B3LYP/6–31++G* approaches considering separately...
-
Synthesis and biological evaluation of fluorinated N-benzoyl and N-phenylacetoyl derivatives of 3-(4-aminophenyl)-coumarin-7-O-sulfamate as steroid sulfatase inhibitors
PublicationIn the present work, we report convenient methods for the synthesis of 3-(4-aminophenyl)-coumarin-7-O-sulfamate derivatives N-acylated with fluorinated analogues of benzoic or phenylacetic acid as steroid sulfatase (STS) inhibitors. The design of these potential STS inhibitors was supported by molecular modeling techniques. Additionally, computational docking methods were used to determine the binding modes of the synthesized inhibitors...
-
Synthesis and biological evaluation of N-acylated tyramine sulfamates containing C-F bonds as steroid sulfatase inhibitors
PublicationSteroid sulfatase (STS) is responsible for the hydrolysis of biologically inactive sulfated steroids into their active un-sulfated forms and promotes the growth of various hormone-dependent cancers (e.g., breast cancer). Therefore, the STS enzyme is a promising therapeutic target for the treatment of steroid-sensitive cancers. Herein, we report the synthesis and biological evaluation of sulfamate analogs as potential STS inhibitors...
Year 2016
-
Convenient and efficient synthesis of functionalized unsymmetrical alkynyl sulfides
PublicationWe developed a simple and efficient method for the synthesis of functionalized unsymmetrical alkynyl sulfides under mild conditions in good yields. The designed method is based on the reaction of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-disulfanyl derivatives with lithium acetylides. The developed method allows the preparation of unsymmetrical alkynyl sulfides bearing additional hydroxyl, carboxyl, or amino functionalities.
-
Phosphoroorganic Metal Complexes in Therapeutics
PublicationThe present mini-review highlights recent developments on antitumor activity of metal-based therapeutics which have been a subject of researches for the last few decades. In 1965, Rosenberg found that during an electrolysis on platinum electrodes a complex of Pt is generated which inhibited to a great extent a binary fission in Escherichia coli bacteria. This discovery started a new chapter in medicinal chemistry and the interesting...
-
Selected organophosphorus compounds with biological activity. Applications in medicine
PublicationThe purpose of this article is to provide an overview of the latest applications of organophosphorus compounds (OPs) that exhibit biological activity. A large family of OPs have become popular in recent years. The practical application of OPs in modern medicine has been attributed to their unique properties. In this article, the methods used to select these compounds will be emphasized. This paper will first outline the findings...
-
Synthesis and biological evaluation of fluorinated 3-phenylcoumarin-7-O-sulfamate derivatives as steroid sulfatase inhibitors
PublicationIn the present work, we report the initial results of our study on a series of 3-phenylcoumarin sulfamate-based compounds containing C-F bonds as a novel inhibitors of steroid sulfatase (STS). The new compounds are potent STS inhibitors, possessing more than 10 times higher inhibitory potency than coumarin-7-O-sulfamate. In the course of our investigation, compounds 2b and 2c demonstrated the highest inhibitory effect in the enzymatic...
-
Synthesis and steroid sulfatase inhibitory activities of N-phosphorylated 3-(4-aminophenyl)-coumarin-7-O-sulfamates
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of N-phosphorylated derivatives of 3-(4-aminophenyl)-coumarin-7-O-sulfamate as potential steroid sulfatase (STS) inhibitors. Their binding modes were modeled using docking techniques. The inhibitory effects of the synthesized compounds were tested on STS isolated from human placenta. All of the newly synthesised coumarin derivatives were...
Year 2015
-
DDQ-mediated synthesis of functionalized unsymmetrical disulfanes
PublicationWe developed a simple and efficient method for the synthesis of functionalized unsymmetrical disulfanes under mild conditions in good yields. The designed method is based on the reaction of bis(5,5- dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)disulfane with thiols in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The developedmethod allows the preparation of unsymmetrical disulfanes bearing additional hydroxy, carboxy,...
-
Innowacyjna technologia zagospodarowania odpadowych skorup jajecznych
PublicationGospodarowanie odpadami rolnymi stanowi jeden z głównych problemów w przetwórstwie żywności. W Polsce w ostatnich latach produkuje się ponad 500 tys. ton jaj, co generuje około 65 tys. ton skorup rocznie. Zgodnie z przepisami Unii Europejskiej odpady przemysłu jajcarskiego ( głównie skorupy) są uznawane za odpady niebezpieczne i podlegają ścisłej kontroli. Zespoły specjalistów pracujących w Przedsiębiorstwie Innowacyjno-Wdrożeniowym...
-
New oryginal generic technologies: A Polish R&D strategic implementation programme
PublicationPolands's pharmaceutical industry is of great significance to the whole economy. According to Forbs (2 October 2012), the cost of launching a new drug varies from USD 1 to 11 bilion. There is little Chance of a Polish pharmaceutical company developing an original drug due to financial reason.Many research teams in Poland take up research projects aimed at new biologically active compounds. But such an objective has no broader perspective,...
-
Phosphate and Thiophosphate Biphenyl Analogs as Steroid Sulfatase Inhibitors
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of phosphate and thiophosphate biphenyl derivatives exhibiting steroid sulfatase (STS) activity. The described synthesis is based on straightforward preparation of biphenyl-4-ol and 40-hydroxybiphenyl- 4-carboxylic acid ethyl ester modified with various phosphate or thiophosphate moieties. The inhibitory effects of these compounds were...
-
Steroid Sulfatase Inhibitors Based on Phosphate and Thiophosphate Flavone Analogs
PublicationA series of phosphate and thiophosphate flavone derivatives were synthesized and biologically evaluated in vitro for inhibition of steroid sulfatase (STS) activity. The described synthesis includes the straightforward preparation of 7-hydroxy-2-phenyl-4H-chromen-4-one 3a, 2-(4-fluorophenyl)-7-hydroxy-4H-chromen-4-one 3b, 7-hydroxy-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one 3c, 7-hydroxy-2-(p-tolyl)-4H-chromen-4-one 3d modified...
-
Synthesis and biological evaluation of thiophosphate tricyclic coumarin derivatives as steroid sulfatase inhibitors
PublicationSteroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-dependent breast cancer. In this paper, we report convenient methods for the synthesis and biological evaluation of thiophosphate tricyclic coumarin analogs exhibiting STS activity. The described methods are based on the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-2-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one,...
-
Synthesis and steroid sulfatase inhibitory activities of N-alkanoyl tyramine phosphates and thiophosphates
PublicationA series of phosphate and thiophosphate analogs based on the frameworks of N-alkanoyl tyramines have been synthesized and biologically evaluated. Their binding modes have been modeled using docking techniques. The inhibitory effects of the synthesized compounds were tested on STS isolated from the human placenta as well as the MCF-7, MDA-MB-231 and SkBr3 cancer cell lines. Most of the new STS inhibitors possessed potent activity...
-
Synthesis of bicoumarin thiophosphate derivatives as steroid sulfatase inhibitors
PublicationBased on the frameworks of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c] chromen-6-one, a series of bicoumarin thiophosphate analogs have been synthesized and biologically evaluated. Additionally, their binding modes have been modeled using docking techniques. The inhibitory properties of the synthesized compounds...
Year 2014
-
Acyl Meldrum's acid derivatives: application in organic synthesis
PublicationThis review is focused on one of the most important classes of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleiophiles. The possible mechanisms of these transformations...
-
Phosphate tricyclic coumarin analogs as steroid sulfatase inhibitors: synthesis and biological activity.
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of phosphate tricyclic coumarin derivatives as potential steroid sulfatase inhibitors. The described synthesis includes the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy-7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c]chromen-6-one modified...
Year 2013
-
Mechanism of the Reaction of Amines with 5-[(Aryl- or Alkylamino)hydroxymethylene]-2,2-dimethyl-1,3-dioxane-4,6-diones in the Presence of Chlorotrimethylsilane (Me3SiCl);
PublicationAddition of chlorotrimethylsilane (Me3SiCl) to the mixture of a carbamoyl‐substituted Meldrum's acid, i.e., a 5‐[(arylamino)hydroxymethylene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione of type 1 and a secondary amine as nucleophile strongly accelerated the rate of their reaction. The reason for this phenomenon observed, during our previous research, remained, however, unclear. To elucidate the mechanism of this reaction, we assumed and...
-
Polskie Uczelnie Wyższe w XXI wieku muszą się zmienić!
PublicationStan szkolnictwa wyższego w Polsce i konieczności zmian. Uczelnie edukacyjne i uczelnie badawcze
Year 2012
-
Preparation of Pseudopeptides Building Blocks with Retro-Thioamide Bond Mediated via Thiocarbamoyl Meldrum's Acid
PublicationAn easy and efficient synthesis of pseudo tripeptide containing a thiomalonamide moiety was developed. Isothiocyanate derivatives of amino acids react smoothly with 2,2-dimethyl-1,3-dioxane-4,6-dione yielding new thiocarbamoyl Meldrum's acids. Thermal decomposition of this new Meldrum's acid derivatives generate thiocarbamoyl ketenes, which acylate amino acid esters to give pseudo tripeptides.
Year 2011
-
Efficient Selenenylation of Malonates Using Bis(phosphorothioyl) Diselenide
PublicationBis(O,O-diisopropoxyphosphinothioyl) diselenide reacts readily and quickly with the sodium salt of malonates to give quantitatively stable sodium 2-(O,O-diisopropyl phosphorothioselenenyl)propanedioates. No traces of the corresponding C,C-diselenenylation products were detected. A standard aqueous workup procedure affords the products, albeit in poor yield (about 45%). It was proved that the reaction is reversible due to the presence...
-
Problemy informacji naukowo-technicznej w Polsce : Koncepcja Centralnej Biblioteki Nauk Przyrodniczych i Technicznych = Problems of science and technology information in Poland : A concept of Central Library for Science and Technology
PublicationJednym z największych dóbr każdego uniwersytetu i placówki naukowo-badawczej jest biblioteka naukowa. Obecna sytuacja bibliotek naukowych w naszym kraju jest trudna. Lawinowemu wzrostowi liczby publikacji towarzyszy znaczny wzrost cen wszystkich wydawnictw. Rozwój nauki zależy od dostępu do informacji naukowo-technicznej. W artykule omówiono aktualny model finansowania dostępu polskich naukowców do światowych zasobów elektronicznych...
-
Profesor Jan Czochralski – historia najwybitniejszego polskiego inżyniera
PublicationHistoria odkrycia metody wzrostu kryształów
-
Reaktywność wybranych siarkowych i selenowych pochodnych kwasu fosforowego
PublicationKilka lat temu byliśmy w stanie zademonstrować, nowa reakcję redukcji wiązania N-O pod wpływem anionu kwasu tio oraz seleno fosforowego, biegnącą mechanizmem SET. W toku dalszych naszych prac ustaliliśmy, że kwas ditiofosforowy jest donorem zarówno protonu jak i atomu wodoru, natomiast anion kwasu ditiofosforowego jest doskonałym nukleofugiem oraz donorem pojedynczego elektronu. W kolejnym etapie badań stwierdziliśmy, że zarówno...
-
TMSCl Promoted Acylation of Amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids - Elucidation of Mechanism.
PublicationRecently we have observed accelerating influence of trimethyl silyl chloride addition on the rate of the reactions of 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids with amines, particularly in the case of highly basic amines. However the nature of the aforementioned process remain unexplained. In proposed communication we wish to report insightful elucidation of this mechanism. The reaction under investigation involves simply...
Year 2010
-
5,5-Dimethyl-2-methylseleno-1,3,2-dioxaphosphorinan-2-one
PublicationTytułowy związek otrzymano w reakcji soli potasowej kwasu O,O-neopentylidenomonoselenofosforowego z jodkiem metylu. Analiza krystalograficzna tego estru wykazała, że grupa selenometylowa zajmuje pozycję aksjalną względem sześcioczłonowego pierścienia dioksafosforinanu.
-
Efektywna metoda selenenylowania z użyciem diselenidu O,O-diizopropylofosforotioilowego
PublicationTworzenie wiązania C-Se odbywa się zwykle z wykorzystaniem elektrofilowego bromku fenyloselenenylowego generowanego in situ z diselenidu difenylowego. Fenyloselenenylowanie soli sodowych malonianów, użytych z 10-krotnym nadmiarem, prowadzi do powstawania znaczących ilości di(fenyloselenenylo)malonianów obok głównych produktów mono-selenenylowania. 2-Fenyloselenenylomaloniany wykorzystano m.in. w reakcji rodnikowej addycji do wiązania...
Year 2009
-
A convenient and efficient alfa-sulfenylation of carbonyl compounds
PublicationA method for alfa-sulfenylation of carbonyl compounds by a 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives has been developed. Readily available reagents, mild reaction conditions, and excellent yields with high selectivity makes this method quite simple, convenient and practical.
-
Novel and Efficient Methods for the Synthesis of Symmetrical Trisulfides
PublicationWe have developed a convenient methods for the synthesis of symmetrical trisulfides under mild conditions in very good yields. The described methods are based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The symmetrical...
-
O-4-Chlorobenzoyl diphenylselenophosphinate
PublicationTytułowy związek difenyloselenofosfinian O-4-chlorobenzoilu krystalizuje w układzie jednoskośnym, w grupie P21/c. Upakowanie molekuł w krysztale wskazuje na oddziaływania van der Waalsa pomiędzy pierścieniami aromatycznymi reszt acylowych. Z kolei kąt dwuścienny pomiędzy pierścieniami fenylowymi reszty fosforowej wynosi 72.64 (14) stopni. Geometrię cząsteczki badanego związku porównano z opisanymi w litaraturze chemicznej estrami...
-
O-Pivaloyl diphenylselenophosphinate
PublicationTytułowy związek difenyloselenofosfinian O-piwaloilu krystalizuje w układzie jednoskośnym, w grupie P21/c. Jeden z pierścieni fenylowych jest w pozycji periplanarnej do płaszczyzny wiązań Se-P-C, podczas gdy kąt dwuścienny pomiędzy dwoma pierścieniami aromatycznymi wynosi ok. 73 stopni. Geometrię cząsteczki badanego związku porównano z opisanymi w literaturze chemicznej estrami O-alkilowymi i O-arylowymi kwasu difenyloselenofosfinowego.
-
Synthesis and structural investigation of N-acyl selenophosphoramides
PublicationN-acylowane amidy kwasu O,O-neopentylidenomonoselenofosforowego, w zależności od podstawnika na atomie azotu, krystalizują jako konformery zawierające selen w pozycji ekwatorialnej bądź aksjalnej. Wyniki tych eksperymentów wyjaśniono działaniem efektu anomerycznego.
Year 2008
-
A versatile and convenient preparation of unsymmetrical diaryl disulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical diaryl disulfides under mild conditions in excellent yields. The described method is based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-sulfenyl bromide from readily available 5,5-dimethyl-2-thiolo-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The unsymmetrical...
-
Complexation of amino acids derivatives in water by calix[4]arene phosphonic acids
PublicationSeries of the calix[4]arene phosphonic acids with various substituents at the lower rim was synthesized. Complexing properties of these receptors towards methyl esters of six amino acids strongly depended on the calix[4]arene conformation flexibility. The complex formation processes were monitored using 1H NMR spectroscopy (deuterated phosphate buffer at pD 7.3, 22 oC) and association constant values were evaluated. Inherently...
seen 4501 times