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1
Experimental and Theoretical Studies on Pyrolysis of O-Acetyl Derivatives of beta-phenylcinnamaldehyde and Benzaldehyde Oximes
100%
Mohamed M. , Siedlecka M. , Suwiński J.
Polish Journal of Chemistry
|
2003
|
tom Vol. 77 / nr 5
577-590
EN
[ReBr3(py)3]0.42[ReBr2(NO)(py)3]0.58 (1), trans-[ReBr4(OPPh3)2] (2), [ReBr(NO)(dppe)2]Br (3) and orthorhombic polymorph of mer-cis- [Re(NO)Br3(OPPh3)2] (4) complexes have been synthesized by reactions of monoclinic polymorph of mer-cis-[Re(NO)Br3(OPPh3)2] with pyridine, bis(diphenylophosphino) ethane, 2,2_-bipyridine, 1,10-phenanthroline. The NO group in 1 and 4 is coordinated in a linear way. Due to nitrosyl/bromine compositional disorder, the shortening of Re-NO distance [1.68(5) A] and the elongation of N-O bond length [1.38(10) A] are observed in1. The N-O bond length in 4 is extremely short [0.94(1) A], which results probably from steric interactions of two mutually cis OPPh3 molecules and a large discrepancy of Re-O-P angle values.
2
Synthesis of 4,5-Dicyanoimidazoles
100%
Bukowska M. , Prejzner J. , Szczeciński P.
Polish Journal of Chemistry
|
2004
|
tom Vol. 78 / nr 3
417-422
EN
The effective procedure of preparation of 2-trifluoromethyl-4,5-dicyanoimidazole (3a) from diaminomaleonitrile (1) and trifluoroacetic anhydride has been elaborated. The syntheses of five other 2-substituted imidazoles from appropriate acyl derivatives of 1 have been attempted. Out of them only 4,5-dicyanoimidazole (3b) could be obtained in good yield.
3
Synthesis of 2-Alkylbenzofurans via Acid-catalyzed Cyclization of 1,1-Dimethoxy-2-phenoxyalkanes
100%
Kwiecień H. , Witczak M. , Rosiak A.
Polish Journal of Chemistry
|
2004
|
tom Vol. 78 / nr 2
249-254
EN
Treatment of 2-phenoxyalkanals 1a-e with methanol at room temperature under homoor heterogeneous acid-catalysis conditions leads to formation of diacetal as well as some quantities of appropriate 2-alkylbenzofurans. 2-Alkylbenzofurans3a-e were obtained in high yields viacyclization of the 1,1-dimethoxy-2-phenoxyalkanes 2a-e under mild conditions over Amberlyst 15.
4
Synthesis and properties of new 2-alkyl-1,4-benzoxazepine derivatives. Part 3. Synthesis and cyclization of 2-(2-carboxyphenoxy)alkanamides
100%
Kwiecień H.
Polish Journal of Chemistry
|
1998
|
tom Vol. 72, nr 10
2254-2260
EN
A series of novel 2-(2-carboxyphenoxy)alkanamides 4a-f have been obtained as result of condensation of salicylaldehydes with 2-halo esters, amination of prepared esters, 1a-f with methylamine followed by oxidation of amides 3a-f with sodium chlorite. The intramolecular cyclization of amides 4a-f to 1,4-benzoxazepin-3,5-dione system has been investigated.
5
Functionalization of the Homoallylic Bridge in Higher Sugar Precursors
100%
Jarosz S. , Szewczyk K. , Gaweł A. , Gomez A. , Lopez J.
Polish Journal of Chemistry
|
2005
|
tom Vol. 79 / nr 2
231-238
EN
The Barton reduction of the sugar homoallylic xanthate did not afford the expected hydrocarbon, but led to two cyclic products resulting from the attack of initially formed radical onto the olefin fragment of the homoallylic system. The mechanism of such cyclization is discussed.
6
Content available remote Heteroareno-annelated estranes by triene cyclization
100%
Watanabe M. , Matsumoto T. , Mataka S. , Thiemann T.
Open Chemistry
|
2006
|
tom 4
|
nr 3
375-402
EN
17-Thienyl-and 17-benzo[b]thienyl-3-hydroxyestra-1,3,5(10),16-tetraenes were synthesized by either sequential or one-pot Suzuki cross-coupling and Wittig olefination reactions. At 160 °C, heteroaryl substituted steroids were observed to undergo thermal intramolecular cyclization to produce E-ring heteroareno-annelated estranes.
7
Synthesis of 1,3-Oxaselenan-2-imines from Isoselenocyanates
100%
Sommen G. , Heimgartner H.
Polish Journal of Chemistry
|
2007
|
tom Vol. 81, nr 8
1413-1418
EN
The reactions of aryl isoselenocyanates 1 with 3-chloropropan-1-ol (8) in the presence of sodium hydride in dichloromethane at room temperature gave 1,3-oxaselenan-2-imines 10 in fair yield. A reaction mechanism via nucleophilic attack of the alcoholate at the isoselenocyanate 1, followed by an 6-exo-tet cyclization, is most likely.
8
Synthesis of Complex Bicyclo[4.3.0]nonene Derivatives from Sugar Allyltins; Sugar Mimetics Derived from D-Glucose
100%
Jarosz S. , Jędra S.
Polish Journal of Chemistry
|
2009
|
tom Vol. 83, nr 10
1757-1764
EN
Controlled decomposition of sugar allyltin: methyl 2,3,4-tri-O-benzyl- 6,7,8- tri -deoxy-8-(tri-n-butyl)stannyl-alfa-D-gluco-oct-6(E)-eno-hexo-1,5-pyranoside af forded the corresponding dienoaldehyde with the D-xylo-configuration and the E-geometry across the internal double bond. Reaction of this intermediate with Ph3P=CH-CO2Me provided a triene, which under went cyclization to the bicyclic products: derivatives of bicyclo[4.3.0]nonatriene. Stereochemical aspects of this cyclization, as well as some transformations leading to carbobicyclic sugar mimics, are discussed.
9
Synthesis of Isoxazolo {3,4-d]pyrimidines from 6-Chloropyrimidine-5-carbaldehydes
100%
Kaminskas A.
Polish Journal of Chemistry
|
2002
|
tom Vol. 76 / nr 5
725-728
EN
4-Dialkylamino-6-chloro-2-methylthiopyrimidine-5-carbaldehydes with sodium azide in dimethylformamide underwent ring closure reaction to form the corresponding isoxazolo[3,4-d]pyrimidines.
10
Content available remote A biomimetic approach to some specifically functionalized cyclic terpenoids
100%
Kulciţki V.
Acta Biochimica Polonica
|
2007
|
tom 54
|
nr 4
679-693
EN
The paper relates on the current advancements in the synthesis of complex cyclic terpenoids by superacidic induced cyclization of open chain precursors. It is shown that functional groups disposal in the initial substrate strongly influences the reaction outcome. Possible variations of the investigated compound structures include particularly α-functionalization and α,ω-bifunctionalization. This approach allowed a selective initiation of cyclization sequence from an internal double bond or suspending the ring closure cascade to partially cyclized compounds. The reported synthetic schemes are attempts to mimic the biogenetical processes postulated in the living systems.
11
Synthesis of 2-Alkyl-5-nitrobenzofurans via 2-(2-Formyl-4-nitrophenoxy)alkanoic Acids
100%
Kwiecień H.
Polish Journal of Chemistry
|
2004
|
tom Vol. 78 / nr 10
1865-1869
EN
Two reaction methods were employed to prepare alumoxanes of general formula [(RO)AlO]n. The first one from Et3Al, H2O and ROH [R = CH3, (CH3)2CH]; the second one from Et3Al, ROH [R = (CH3)2CH, CH3(CH2)9] and H2O. The properties, chemical composition, aggregation and proposed structure of the final products are discussed based on gel permeation chromatography, molecular weight determination and spectroscopic data.
12
Content available remote Synthesis of vinca alkaloids and related compounds 991. A new heterocyclic system
88%
Csókási P. , Gács-Baitz E. , Szántay C.
Open Chemistry
|
2003
|
tom 1
|
nr 1
65-68
EN
Utilising our earlier intermediate obtained by the umpolung reactivity of quinolizidine enamines, a new heterocyclic system: (11bSR, 15aSR)-1,2,3,6,11,14,15,15a-Octahydro-5H-indolo [2′,3′:3,4]pyrido[2,1-j]-1,6-naphthyridin-13(12H)-one was synthesised and its biological effects evaluated. Although modest, significant and selective effects were detected.
13
Lactones 17. Synthesis of Bicyclic Lactones with the Methyl- or gem-Dimethylcyclopropane System
88%
Obara R. , Szumny A. , Żołnierczyk A. , Olejniczak T. , Białońska A. , Ciunik Z. , Wawrzeńczyk C.
Polish Journal of Chemistry
|
2005
|
tom Vol. 79 / nr 6
981-993
EN
A new method of synthesis of bicyclic gamma-lactones with the methyl- or gem-dimethylcyclopropane system from gamma,delta unsaturated esters is described. The reaction of gamma-halo delta- lactones with DBU is the key step of this synthesis. The mechanism of the dehydrohalogenation- cyclization process of gamma-halo-delta-lactones is proposed. The structures of products were confirmed by both spectroscopic and crystallographic methods.
14
A novel type of ring closure of amino-substituted thiocarbonyl ylides
88%
Romański J. , Mlostoń G. , Linden A. , Heimgartner H.
Polish Journal of Chemistry
|
1999
|
tom vol. 73 nr 3
475-485
EN
The reaction of 4,4-dimethyl-1,3-thiazole-5(4H)-thiones 7a-c with dimethyl 2-diazo-3-(phenyloamino)butanoate (2), prepared from dimethyl fumarate and phenyl azide, in toluene at 800C yielded mixtures of dimethyl 2-(4,5-dihydro-4,4-dimethyl-1,3-thiazol-5-ylidene)-3-(N-phenylamino)butanedioates of type 11 and four diastereoisometric 4,4-dimethyl-9-phenyl-1,6-dithia-3,9-diazaspiro[4,4]non-2-ene-7,8-dicarboxylates of type 12. The formation of the products of type 12 is rationalized by a novel cyclization of intermediate thiocarbonyl ylides 9. The structures of cis-12a, cis-12c, and trans-12c were established by X-ray crystallography.
15
Synthesis and Cyclization of N-{2-[(2-Carboxyethyl)sulfanylphenyl]}-beta-alanines
75%
Rutkauskas K. , Kantminiene K. , Beresnevieius Z. J.
Polish Journal of Chemistry
|
2008
|
tom Vol. 82, nr 12
2341-2347
EN
The reaction of methyl- and methoxyaminobenzenethiols with acrylic acid resulted in formation of 8-methyl- and 8-methoxy-2,3-dihydro-1,5-benzothiazepin-4(5H)-ones, N-{2-[(2-carboxyethyl)sulfanyl]-4-methylphenyl}-b-alanine and 3-[(8-methoxy- 4- oxo-3,4-dihydro-1,5-benzothiazepin-5(2H)-yl]propanoic acid. Their cyclization to N-(5-methyl-4-oxo-3,4-dihydro-2H-thiochromen-8-yl)-b-alanine, 5-methyl- 9,10- dihydro-2Hthiopyrano[3,2-h]quinoline-4,7(3H,8H)-dione and 10-methyl- 2,3,6,7- tetrahydro-4H,8H-[1,4]thiazepino[2,3,4-ij]quinoline-4,8-dione is described.
16
Content available remote Organocatalytic Enantioselective [3+2] Cycloaddition of Azomethine Ylides and Acrolein
75%
Ugarriza I. , Uria U. , Reyes E. , Carrillo L. , Vicario J. L.
Asymmetric Catalysis
|
2015
|
tom 2
|
nr 1
EN
The [3+2]-cycloaddition reaction between acrolein and in situ generated acyclic azomethine ylides promoted by a chiral secondary amine to generate C-3 unsubstituted pyrrolidines has been studied in detail. Optimum conditions involve the use of the cheap and readily available l-Proline as catalyst to afford the pyrrolidine cycloadduct with complete diastereomeric control and up to 80% enantiomeric control.
17
Content available remote Wykorzystanie kompleksów palladu w syntezie związków heterocyklicznych
75%
Zawisza A.
Wiadomości Chemiczne
|
2009
|
tom [Z] 63, 3-4
193-231
EN
Heterocyclic compounds focus an attention for many reasons. Many of them are biologically active compounds, natural products, drugs, synthetic materials and practically useful chemicals [1-5]. Therefore, organic chemists have been making extensive efforts to produce these heterocyclic compounds by developing new and efficient synthetic transformations. Among a variety of new synthetic transformations, transition-metal-catalyzed reactions are very attractive methodologies for synthesis of heterocyclic compounds, since they permit to construct complicated molecules directly from readily accessible starting materials under mild conditions. For this purpose palladium is one of the most widely used transition metals mainly due to the mild reaction conditions used, high yields, a tolerance of a large variety of functional groups, and high regio-, stereo- and enantioselectivity observed [6]. Pd^0-catalyzed allylic alkylations and Pd^II-catalyzed oxidative cyclization of hydroksy(amino)alkene(alkyne)nucleophiles in the intermolecular mode have been particularly notable in this area due to their ability to elicit control in the aforementioned areas, often under very mild conditions. Pd^0-catalyzed intra- or intermolecular heteroannulation through allylic alkylation, the so-called Tsuji-Trost reaction, generally employs allylic acetates [9-14], carbonates [15-29] or vinyl epoxides [30-34] bearing a hydroxy or an amino group as the substrates. Allylsilanes have also been used as precursors of the ?3-allyl intermediates, starting from PdCl2 and CuCl2, affording the corresponding THF and THP derivatives in quite good yields [38-40]. The PdII-catalyzed cyclization of alkenyl alcohols has led to cyclic enols by ?-hydride elimination, or to oxygen heterocycles bearing a vinyl group through a ?-hydroxy elimination, if the alkenol possesses an allyl alcohol moiety. Using this methodology a large variety of oxygen- or nitrogen-containing heterocycles have been obtained even in an asymmetric fashion [51-95].
18
A biomimetic approach to some specifically functionalized cyclic terpenoids
63%
Kulcitki V.
Acta Biochimica Polonica
|
2007
|
tom 54
|
nr 4
679-693
EN
The paper relates on the current advancements in the synthesis of complex cyclic terpenoids by superacidic induced cyclization of open chain precursors. It is shown that functional groups disposal in the initial substrate strongly influences the reaction outcome. Possible variations of the investigated compound structures include particularly α-functionalization and α,ω-bifunctionalization. This approach allowed a selective initiation of cyclization sequence from an internal double bond or suspending the ring closure cascade to partially cyclized compounds. The reported synthetic schemes are attempts to mimic the biogenetical processes postulated in the living systems.
19
Content available remote Optymalizacja procesu otrzymywania 1,3,4-trimetylocykloheks-3-eno-1-karboksylanu metylu
63%
Marshalok H. , Kostiv I. , Polyuzhin I. , Marshalok O. , Vytrykush N.
Przemysł Chemiczny
|
2016
|
tom T. 95, nr 4
745--750
PL
Doświadczalnie i za pomocą metody modelowania matematycznego ustalono optymalne warunki oraz wydajność technologicznego procesu otrzymywania 1,3,4-trimetylocykloheks-3-eno-1-karboksylanu metylu.
EN
2,3-Dimethylbuta-1,3-diene was cyclized with Me metacrylate (mole ratio 1:1 to 1.5:1) to the title ester at 403–433 K for 3.5 to 6.5 h. The optimum conditions of the reaction were detd. (yield 73% by mass).
20
Optimization of the parameters of 2-(2-formylphenoxy)hexanoic acid cyclization. Synthesis of 2-alkylbenzofurans
63%
Miszczyszyn M. , Kwiecień H.
Polish Journal of Applied Chemistry
|
2002
|
tom Vol. 46, nr 1
21-29
EN
The intramolecular cyclization of 2-(2-formylphenoxy)hexanoic acid (FPHA) to 2-butylbenzofuran under the Perkin reaction conditions has been investigated. The influence of important parameters on the 2-butylbenzofuran yield in relation to 2-(2-formylphenoxy)hexanoic acid introduced (response function) has been described by regression equations in the form of a second order polynomial. The optimum values of: acetic anhydride to FPHA molar ratio, reaction time, acetic acid to FPHA molar ratio have been determined. 2-Butylbenzofuran and some of benzene-ring-halogenated 2-alkylbenzofurans have been obtained in moderate yields from corresponding 2-(2-formylphenoxy)alkanoic acids with the use of optimal conditions.
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