Zobrazeno 1 - 10
of 41
pro vyhledávání: '"Andrzej Leniewski"'
Autor:
Andrzej Leniewski, Joanna Szawkało, Michał Pawłowski, Anna Lendzion, Zbigniew Czarnocki, Jan K. Maurin
Publikováno v:
Phosphorus, Sulfur, and Silicon and the Related Elements. 184:1307-1313
A series of novel 5-thioxopyrrolidin-2-ones and 6-thioxopiperidin-2-ones was synthesized using Lawesson's reagent in thionation of the appropriate imides. The NMR data were determined, and in one case the structure assignment was additionally support
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4a00bbedf03b51df374c2eb98d549e11
https://doi.org/10.1080/10426500902856404
https://doi.org/10.1080/10426500902856404
Autor:
Andrzej Leniewski, Jan K. Maurin, Darius P. Kranz, Piotr Roszkowski, Katarzyna Piwowarczyk, Anna Zawadzka, Joanna Szawkało, Zbigniew Czarnocki
Publikováno v:
Tetrahedron: Asymmetry. 19:309-317
A series of (2R∗,3R∗)-1-methyl-5-oxo-2-aryltetrahydro-1H-pyrrolidine-3-carboxylic acids were prepared and their structures were proven with X-ray crystallography. Racemic acid 5 has been resolved into enantiomers (2S,3S)-5 and (2R,3R)-5 by the fo
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::fc5062077e5a55e5ec239084688ad528
https://doi.org/10.1016/j.tetasy.2008.01.014
https://doi.org/10.1016/j.tetasy.2008.01.014
Autor:
Anna Zawadzka, Andrzej Leniewski, Jan K. Maurin, Aleksandra Siwicka, Zbigniew Czarnocki, Krystyna Wojtasiewicz
Publikováno v:
Canadian Journal of Chemistry. 85:1033-1036
Modified sodium borohydrides were used in the reduction of the imine moiety in compounds containing the (R)-1-arylethylamine motif as a chiral auxiliary. Diastereomeric products were formed with moderate to good stereoselectivity and were effectively
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::92c98ee00acdcdf1dc71a91e0dcb8c49
https://doi.org/10.1139/v07-118
https://doi.org/10.1139/v07-118
Autor:
Jan K. Maurin, Piotr Roszkowski, Aleksandra Siwicka, Stefan J. Czarnocki, Zbigniew Czarnocki, Joanna Szawkało, Anna Zawadzka, Andrzej Leniewski
Publikováno v:
International Congress Series. 1304:46-59
The use of chiral inductors belonging to different classes of compounds is elaborated. Tetrahydro-β-carboline derivatives were constructed stereoselectively by the use of (R)-1-arylethylamine and l -amino acids. Asymmetric transfer hydrogenation was
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::41d242e7efb4fb5e039a4c2345d80e52
https://doi.org/10.1016/j.ics.2007.07.003
https://doi.org/10.1016/j.ics.2007.07.003
Autor:
Józef Drabowicz, Anna Zawadzka, Jan K. Maurin, Joanna Szawkało, Andrzej Leniewski, Krystyna Wojtasiewicz, Stefan J. Czarnocki, Zbigniew Czarnocki
Publikováno v:
Tetrahedron: Asymmetry. 18:406-413
Four alkaloids: (R)-(+)-cryspine A 5, (R)-(+)-octahydroindolo[2,3-a]quinolizidine 8, (R)-(+)-harmicine 19 and (R)-(+)-desbromoarborescidine 22 were prepared via the asymmetric transfer hydrogenation reaction of a prochiral enamine (iminium salt). The
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9e8ed8b27191935ba6a18d521e7984c6
https://doi.org/10.1016/j.tetasy.2007.01.014
https://doi.org/10.1016/j.tetasy.2007.01.014
Autor:
Piotr Roszkowski, Jan K. Maurin, Krystyna Wojtasiewicz, Tadeusz Lis, Andrzej Leniewski, Zbigniew Czarnocki
Publikováno v:
Journal of Molecular Catalysis A: Chemical. 232:143-149
Several 1-substituted-3,4-dihydro-β-carboline derivatives were subjected to asymmetric transfer hydrogenation catalysed by chiral ruthenium complexes to give both enantiomers of 1,2,3,4-tetrahydro-β-carbolines of high optical purity and in good yie
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1a86f5fd7e96093f1ecf8072630c56e2
https://doi.org/10.1016/j.molcata.2005.01.044
https://doi.org/10.1016/j.molcata.2005.01.044
Autor:
Aleksandra Siwicka, Krystyna Wojtasiewicz, Zbigniew Czarnocki, Jan K. Maurin, Beata Rosiek, Andrzej Leniewski
Publikováno v:
Tetrahedron: Asymmetry. 16:975-993
Mild Pictet–Spengler-type condensation was applied to the synthesis of several tetrahydro-β-carboline and tetrahydro-isoquinoline derivatives. l -Amino acids were promoters of 1,4-chirality transfer with up to 100% de. The stereochemistry of the f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::97a25fb59066b095060937bf2c9b918a
https://doi.org/10.1016/j.tetasy.2005.01.009
https://doi.org/10.1016/j.tetasy.2005.01.009
Autor:
Anna Zawadzka, Andrzej Leniewski, Aleksandra Siwicka, Jan K. Maurin, Zbigniew Czarnocki, Krystyna Wojtasiewicz, Dariusz Błachut
Publikováno v:
European Journal of Organic Chemistry. 2003:2443-2453
l-(−)-Phenylalanine, l-(+)-valine, and l-(−)-proline were used in the diastereoselective synthesis of benzyltetrahydroisoquinoline derivatives.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a8239bc641fa852ff13ab1ca03ef6644
https://doi.org/10.1002/ejoc.200200705
https://doi.org/10.1002/ejoc.200200705
Publikováno v:
Tetrahedron: Asymmetry. 10:3371-3380
( S )-(−)-α-Methylbenzylamine 2 was used as a chiral auxiliary in the enantiodivergent synthesis of simple isoquinoline alkaloids. The prochiral imine moiety in compound 4 was reduced with different reagents, giving diastereomeric amines 5a or 5b
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::86a26f109a00da8a6892ecc87a923af2
https://doi.org/10.1016/s0957-4166(99)00370-5
https://doi.org/10.1016/s0957-4166(99)00370-5
Autor:
Andrzej Leniewski, Zbigniew Czarnocki, Anna Zawadzka, Józef Drabowicz, Krystyna Wojtasiewicz, Joanna Szawkało
Publikováno v:
Tetrahedron: Asymmetry. 16:3619-3621
A simple enantioselective synthesis of the pyrrolo[2,1-a]isoquinoline alkaloid (+)-crispine A, based on the use of an asymmetric transfer hydrogenation as the key step, is described. The enantiomeric excesses of the obtained alkaloid samples were det
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9ca038e9ce7dbcdaffeefeb9cee3e2d3
https://doi.org/10.1016/j.tetasy.2005.10.007
https://doi.org/10.1016/j.tetasy.2005.10.007