Janusz Rachon | Gdansk University of Technology (original) (raw)
Papers by Janusz Rachon
Chemischer Informationsdienst, Jul 20, 1976
![Research paper thumbnail of Rearrangement of a bicyclic [2.2.2] system to a bicyclic [3.2.1] system. Nonclassical ions](https://attachments.academia-assets.com/110464554/thumbnails/1.jpg)
](Journal of Organic Chemistry, Mar 1, 1989
The syntheses and the establishment of the absolute configurations of chiral (S)-(+)-2-bromodiben... more The syntheses and the establishment of the absolute configurations of chiral (S)-(+)-2-bromodibenzobicyclo[2.2.2]octadiene-2-carboxylic acid (1) and (1S,2S,5S)-(-)-exo-2-methoxydibenzobicyclo[3.2.l]octadiene-1-carboxylic acid (2) and their derivatives are described. The rearrangement of 1 to 2 is discussed in terms of a nonclassical ion intermediate in light of the observed stereochemistry.
Phosphorus Sulfur and Silicon and The Related Elements, 1996
ABSTRACT
Polish Journal of Food and Nutrition Sciences, 2011
ChemInform, Nov 6, 1990
ChemInform Abstract The title reaction under basic conditions yields the products (III) and (IV).... more ChemInform Abstract The title reaction under basic conditions yields the products (III) and (IV). There are no by-products which could have resulted from a conceivable carbene intermediacy in this reaction. No reduction reaction of the N-N single bond takes place as well.
Chemischer Informationsdienst, Jul 30, 1974
European journal of medicinal chemistry, Mar 1, 2020
Mycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including d... more Mycophenolic 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 ester and conjugate of MPA with retro-tuftisin occurred to be more selective against PBMC in comparison to parent MPA. Both amino acid and peptide derivatives of MPA acted as inosine-5'-monophosphate dehydrogenaze (IMPDH) inhibitors.
Phosphorus Sulfur and Silicon and The Related Elements, Oct 1, 1996
ABSTRACT
Journal of Asian Natural Products Research, Aug 13, 2015
Steroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-d... more Steroid 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, and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c]chromen-6-one and their further modification by the introduction of various thiophosphate moieties. The inhibition properties of the synthesized compounds were tested toward STS isolated from human placenta. Most of the new STS inhibitors possessed good to moderate activity toward STS. During the course of our investigation, the largest inhibitory effects in the STS enzyme assays were observed for the two compounds 3f and 4r, with IC50 values of 13.3 and 30.3 μM, respectively (the IC50 value of 1 μM for the 665-COUMATE was used as a reference). The structure-activity relationships of the synthesized coumarin derivatives toward STS enzymes are discussed.
Phosphorus Sulfur and Silicon and The Related Elements, Jun 1, 1991
ABSTRACT 31P chemical shifts are reported for twenty aminoalkylphosphonic acids (APAs), nine 1-hy... more ABSTRACT 31P chemical shifts are reported for twenty aminoalkylphosphonic acids (APAs), nine 1-hydroxyalkyl phosphonic (HPAs) and six phosphonic acids (PAs). The protonation shifts and the substituent-induced effects (SCSs) of the amino and hydroxyl groups on the 31P NMR and α-carbon 13C NMR chemical shifts were calculated and discussed. Substituent shielding effects on phosphorus nucleus and deshielding effects on α-carbon are observed for both groups. Amino shielding effect on phosphorus nucleus is the sum of two interactions: 1) electron-withdrawing substituent effect propagated along the carbon chain, 2) hydrogen bonding and coulombic attaction between groups in the zwitterion forms. Both imply the increasing contribution of a P[dbnd]O resonance structure leading to the upfield S(P). Good linear correlation exist between chemical shifts of 1-hydroxyalkylphosphonic acids and the respective values of analogously constituted 1-aminoalkylphosphonic acids.
Liebigs Annalen, Jan 30, 1981
Eingegangen am 25. April 1980 Die Titelverbindung 2 wird synthetisiert und mit aromatischen und h... more Eingegangen am 25. April 1980 Die Titelverbindung 2 wird synthetisiert und mit aromatischen und heteroaromatischen Aldehyden 1 zu 3-substituierten 2-Isocyanacrylsaure-terl-butylestern 3 umgesetzt. tert-Butyl (Diphenylphosphiny1)isocyanoacetate and its Use in the Wittig-Horner Reaction with Aldehydes The title compound 2 is synthesized. Its reaction with aromatic and heteroaromatic aldehydes 1 leads to 3-substituted tert-butyl 2-isocyanoacrylates 3. 2-Isocyanacrylsaureester vom Typ 3 verdienen Beachtung als Vorstufen fur heterocyclische Carbonsauren') sowie fur a, pund P,y-Dehydroaminosauren3). Man kann sie aus 2-(Formylamino)acrylsaureestern (NHCHO statt NC in 3) erhalten 2-4), die ihrerseits durch ,,Formylaminomethylenierung" mit Isocyanessigsaureestern aus Aldehyden
RSC Advances, 2015
Please note that technical editing may introduce minor changes to the text and/or graphics, which... more Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal's standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains.
Journal of the American Chemical Society, Jul 1, 1988
ABSTRACT
Polish Journal of Chemistry, 2005
Tetrahydrofuran undergoes fast ring cleavage in the reaction with PhI(OH)OTs/(RO)2P(O)H system, w... more Tetrahydrofuran undergoes fast ring cleavage in the reaction with PhI(OH)OTs/(RO)2P(O)H system, which causes the formation of O-(dialkoxyphosphoryl)-O'-tosyl-1,4-butanediol. This fact indicates that tetrahydrofuran is notsuitable as a solvent for reactions with strong electrophilic reagents, such as hypervalent iodine reagents.
ChemInform, Nov 8, 1988
ChemInform Abstract ((I) und (II); Einfluss von Lösungsmittel, Temp. und Substituentengrösse auf ... more ChemInform Abstract ((I) und (II); Einfluss von Lösungsmittel, Temp. und Substituentengrösse auf die CD-Spektren).
Chemischer Informationsdienst, Aug 25, 1981
Chemischer Informationsdienst, Nov 27, 1979
ChemInform Abstract Durch Kondensation des Isonitrils (III) mit den Aldehyden (II) und den Aminos... more ChemInform Abstract Durch Kondensation des Isonitrils (III) mit den Aldehyden (II) und den Aminosäurederivaten (I-) werden die Depsipeptide (lV-) hergestellt. (IR-, NMR-Daten).
Chemischer Informationsdienst, Jul 20, 1976
Journal of Organic Chemistry, Mar 1, 1989
The syntheses and the establishment of the absolute configurations of chiral (S)-(+)-2-bromodiben... more The syntheses and the establishment of the absolute configurations of chiral (S)-(+)-2-bromodibenzobicyclo[2.2.2]octadiene-2-carboxylic acid (1) and (1S,2S,5S)-(-)-exo-2-methoxydibenzobicyclo[3.2.l]octadiene-1-carboxylic acid (2) and their derivatives are described. The rearrangement of 1 to 2 is discussed in terms of a nonclassical ion intermediate in light of the observed stereochemistry.
Phosphorus Sulfur and Silicon and The Related Elements, 1996
ABSTRACT
Polish Journal of Food and Nutrition Sciences, 2011
ChemInform, Nov 6, 1990
ChemInform Abstract The title reaction under basic conditions yields the products (III) and (IV).... more ChemInform Abstract The title reaction under basic conditions yields the products (III) and (IV). There are no by-products which could have resulted from a conceivable carbene intermediacy in this reaction. No reduction reaction of the N-N single bond takes place as well.
Chemischer Informationsdienst, Jul 30, 1974
European journal of medicinal chemistry, Mar 1, 2020
Mycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including d... more Mycophenolic 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 ester and conjugate of MPA with retro-tuftisin occurred to be more selective against PBMC in comparison to parent MPA. Both amino acid and peptide derivatives of MPA acted as inosine-5'-monophosphate dehydrogenaze (IMPDH) inhibitors.
Phosphorus Sulfur and Silicon and The Related Elements, Oct 1, 1996
ABSTRACT
Journal of Asian Natural Products Research, Aug 13, 2015
Steroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-d... more Steroid 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, and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c]chromen-6-one and their further modification by the introduction of various thiophosphate moieties. The inhibition properties of the synthesized compounds were tested toward STS isolated from human placenta. Most of the new STS inhibitors possessed good to moderate activity toward STS. During the course of our investigation, the largest inhibitory effects in the STS enzyme assays were observed for the two compounds 3f and 4r, with IC50 values of 13.3 and 30.3 μM, respectively (the IC50 value of 1 μM for the 665-COUMATE was used as a reference). The structure-activity relationships of the synthesized coumarin derivatives toward STS enzymes are discussed.
Phosphorus Sulfur and Silicon and The Related Elements, Jun 1, 1991
ABSTRACT 31P chemical shifts are reported for twenty aminoalkylphosphonic acids (APAs), nine 1-hy... more ABSTRACT 31P chemical shifts are reported for twenty aminoalkylphosphonic acids (APAs), nine 1-hydroxyalkyl phosphonic (HPAs) and six phosphonic acids (PAs). The protonation shifts and the substituent-induced effects (SCSs) of the amino and hydroxyl groups on the 31P NMR and α-carbon 13C NMR chemical shifts were calculated and discussed. Substituent shielding effects on phosphorus nucleus and deshielding effects on α-carbon are observed for both groups. Amino shielding effect on phosphorus nucleus is the sum of two interactions: 1) electron-withdrawing substituent effect propagated along the carbon chain, 2) hydrogen bonding and coulombic attaction between groups in the zwitterion forms. Both imply the increasing contribution of a P[dbnd]O resonance structure leading to the upfield S(P). Good linear correlation exist between chemical shifts of 1-hydroxyalkylphosphonic acids and the respective values of analogously constituted 1-aminoalkylphosphonic acids.
Liebigs Annalen, Jan 30, 1981
Eingegangen am 25. April 1980 Die Titelverbindung 2 wird synthetisiert und mit aromatischen und h... more Eingegangen am 25. April 1980 Die Titelverbindung 2 wird synthetisiert und mit aromatischen und heteroaromatischen Aldehyden 1 zu 3-substituierten 2-Isocyanacrylsaure-terl-butylestern 3 umgesetzt. tert-Butyl (Diphenylphosphiny1)isocyanoacetate and its Use in the Wittig-Horner Reaction with Aldehydes The title compound 2 is synthesized. Its reaction with aromatic and heteroaromatic aldehydes 1 leads to 3-substituted tert-butyl 2-isocyanoacrylates 3. 2-Isocyanacrylsaureester vom Typ 3 verdienen Beachtung als Vorstufen fur heterocyclische Carbonsauren') sowie fur a, pund P,y-Dehydroaminosauren3). Man kann sie aus 2-(Formylamino)acrylsaureestern (NHCHO statt NC in 3) erhalten 2-4), die ihrerseits durch ,,Formylaminomethylenierung" mit Isocyanessigsaureestern aus Aldehyden
RSC Advances, 2015
Please note that technical editing may introduce minor changes to the text and/or graphics, which... more Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal's standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains.
Journal of the American Chemical Society, Jul 1, 1988
ABSTRACT
Polish Journal of Chemistry, 2005
Tetrahydrofuran undergoes fast ring cleavage in the reaction with PhI(OH)OTs/(RO)2P(O)H system, w... more Tetrahydrofuran undergoes fast ring cleavage in the reaction with PhI(OH)OTs/(RO)2P(O)H system, which causes the formation of O-(dialkoxyphosphoryl)-O'-tosyl-1,4-butanediol. This fact indicates that tetrahydrofuran is notsuitable as a solvent for reactions with strong electrophilic reagents, such as hypervalent iodine reagents.
ChemInform, Nov 8, 1988
ChemInform Abstract ((I) und (II); Einfluss von Lösungsmittel, Temp. und Substituentengrösse auf ... more ChemInform Abstract ((I) und (II); Einfluss von Lösungsmittel, Temp. und Substituentengrösse auf die CD-Spektren).
Chemischer Informationsdienst, Aug 25, 1981
Chemischer Informationsdienst, Nov 27, 1979
ChemInform Abstract Durch Kondensation des Isonitrils (III) mit den Aldehyden (II) und den Aminos... more ChemInform Abstract Durch Kondensation des Isonitrils (III) mit den Aldehyden (II) und den Aminosäurederivaten (I-) werden die Depsipeptide (lV-) hergestellt. (IR-, NMR-Daten).