Preparation of New Optically Active Furanoids Containing Various Aza-Heterocyclic Moieties

1997 ◽  
Vol 62 (6) ◽  
pp. 894-912 ◽  
Author(s):  
Ali Werfeli ◽  
Jan Čejka ◽  
Ondřej Klecán ◽  
Bohumil Kratochvíl ◽  
Josef Kuthan
Keyword(s):  
Schiff Base ◽  
Acrylic Acid ◽  
Primary Alcohol ◽  
Optically Active ◽  
Complex Mixtures ◽  
Knoevenagel Reaction ◽  
Pyridinium Chloride ◽  
X Ray ◽  
Dihydropyridine Derivative ◽  
Pyridinium Perchlorate

The aldehyde 2 prepared from [5-(2,3-O-isopropylidene-β-D-erythrofuranosyl)-2-methylfuran-3-yl]methanol (1) was converted to E,Z-oximes 3, 4 and imine derivative 5 by the reaction with hydroxylamine and pyridin-2-yl amine, respectively. The Knoevenagel reaction with malonic acid afforded exclusively the 3-substituted acrylic acid 6 while corresponding Hantzsch 1,4-dihydropyridines 7 and 8 were obtained by the reaction of aldehyde 2 with ethyl acetoacetate or acetylacetone and ammonia. 3,5-Dicyano-1,4-dihydropyridine derivative 9 was isolated only in forms of hydrates after the reaction of aldehyde 2 with 3-aminocrotonitrile. 1,4-Dihydropyridines 7 and 9 were aromatized to corresponding pyridines 10 and 11. Isoxazoles 12, 13 and isoxazolines 14, 15 were prepared by 1,3-cycloaddition of appropriate dienophiles to a nitrile oxide generated from aldoximes 3, 4. Ferricyanide oxidation of 1-{[5-(2,3-O-isopropylidene-β-D-erythrofuranosyl)-2-methylfuran-3-yl]methyl}pyridinium chloride (17a), -3-methylpyridinium chloride (19a) and the corresponding isoquinolinium chloride 21a gave optically active pyridin-2(1H)-ones 22, 23 and 2H-isoquinolone derivative 24 while the procedure with 2-methylpyridinium salt 18a and 4-methylpyridinium salt 20a led to complex mixtures of products. Reaction of 2,4,6-triphenylpyrylium perchlorate with furanoid amine 26 afforded a mixture of major 2,4,6-triphenylpyridine, minor pyridinium perchlorate 25 and primary alcohol 1. The absolute configuration of the studied compounds has been confirmed by X-ray analysis of the Schiff base 5.

Chiral Induction in the Methylation of N-Ethoxycarbonylmethyl Sulfoximines

1986 ◽  
Vol 39 (11) ◽  
pp. 1833 ◽  
Author(s):  
TW Hambley ◽  
TW Hambley ◽  
B Raguse ◽  
B Raguse ◽  
DD Ridley ◽  
...  
Keyword(s):  
Carbon Atom ◽  
Absolute Configuration ◽  
Sulfur Atom ◽  
Optically Active ◽  
Complex Mixtures ◽  
Lithium Diisopropylamide ◽  
Aryl Group ◽  
Methyl Group ◽  
X Ray ◽  
Chiral Induction

Chiral inductions in the C- methylations of four optically active N-ethoxycarbonylmethyl-S-p-tolylsulfoximines were explored by using the reagents lithium diisopropylamide (in tetrahydrofuran at -78°) then methyl iodide. When the fourth substituent at sulfur was a methyl group, complex mixtures of products were formed. However, when the fourth substituent was an aryl group, moderate yields of methylated compounds were formed and the ratio of diastereomers produced were 50 : 50 ( Ar = phenyl), 76 : 24 ( Ar = o- methoxyphenyl ) and 100 : 0 [ Ar = o-(2-methoxyethoxy)phenyl]. The diastereoselectivities are accounted for by intramolecular chelation of the aryl-oxygen substituents with the intermediate lithiated carbanion. The structure and absolute configuration where Ar = o-(2-methoxyethoxy )phenyl were confirmed by X-ray crystallographic methods. Space group P 212121, orthorhombic, a 10.2500(7), b 13.281(2), c 16.526(2) Ǻ; final R 0.064 (on 924F). The configuration at the sulfur atom is (S) and that induced at the carbon atom is (R).

Tetranuclear Copper and Mononuclear Nickel Complex of the Schiff Base of (3Z)-3-Hydrazonobutan-2-One Oxime with Different Aromatic Carbonyl Compounds: Synthesis, Single Crystal X-Ray Structure, Catecholase Activity, Phenoxazinone Synthase Activity, Catalytic Study for the Homocoupling of Benzyl Amines

2019 ◽  
Author(s):  
Swaraj Sengupta ◽  
Sahanwaj Khan ◽  
Shyamal K. Chattopadhyay ◽  
Indrani Banerjee ◽  
Tarun K. Panda ◽  
...  
Keyword(s):  
Schiff Base ◽  
Single Crystal ◽  
Copper Complex ◽  
Carbonyl Compounds ◽  
Nickel Complex ◽  
Schiff Base Ligands ◽  
X Ray ◽  
Phenoxazinone Synthase ◽  
Catecholase Activity ◽  
Aromatic Carbonyl Compounds

Synthesis and characterisation of one trinuclear copper complex, ([Cu<sub>3</sub>L<sub>3</sub>O]ClO<sub>4</sub>) (<b>1</b>) and one nickel complex ([Ni(L'H)<sub>2</sub>(dmso)<sub>2</sub>](ClO<sub>4</sub>)<sub>2</sub>) (<b>2</b>) with Schiff base ligands: (3Z)-3-((Z)-(1-(thiophen-2-yl)ethylidene)hydrazono)butan-2-one oxime (LH) and 1-(pyridin-2-yl)ethylidene)hydrazono)butan-2-one oxime (L<sup>'</sup>H). <b>1</b> shows high catecholase activity and has also been tested as a catalyst for the synthesis of benzylimine. <b>2 </b> shows phenoxazinone synthase activity.

New Copper Compounds with Antiplatelet Aggregation Activity

2019 ◽  
Vol 15 (8) ◽  
pp. 850-862
Author(s):  
Mirthala Flores-García ◽  
Juan Manuel Fernández-G. ◽  
Cristina Busqueta-Griera ◽  
Elizabeth Gómez ◽  
Simón Hernández-Ortega ◽  
...  
Keyword(s):  
Schiff Base ◽  
Solid State ◽  
Thrombotic Event ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
Schiff Base Ligands ◽  
X Ray ◽  
Antiplatelet Aggregation ◽  
Aggregation Activity ◽  
L1 And L2

Background: Ischemic heart disease, cerebrovascular accident, and venous thromboembolism have the presence of a thrombotic event in common and represent the most common causes of death within the population. Objective: Since Schiff base copper(II) complexes are able to interact with polyphosphates (PolyP), a procoagulant and potentially prothrombotic platelet agent, we investigated the antiplatelet aggregating properties of two novel tridentate Schiff base ligands and their corresponding copper( II) complexes. Methods: The Schiff base ligands (L1) and (L2), as well as their corresponding copper(II) complexes (C1) and (C2), were synthesized and characterized by chemical analysis, X-ray diffraction, mass spectrometry, and UV-Visible, IR and far IR spectroscopy. In addition, EPR studies were carried out for (C1) and (C2), while (L1) and (L2) were further analyzed by 1H and 13C NMR. Tests for antiplatelet aggregation activities of all of the four compounds were conducted. Results: X-ray diffraction studies show that (L1) and (L2) exist in the enol-imine tautomeric form with a strong intramolecular hydrogen bond. NMR studies show that both ligands are found as enol-imine tautomers in CDCl3 solution. In the solid state, the geometry around the copper(II) ion in both (C1) and (C2) is square planar. EPR spectra suggest that the geometry of the complexes is similar to that observed in the solid state by X-ray crystallography. Compound (C2) exhibited the strongest antiplatelet aggregation activity. Conclusion: Schiff base copper(II) complexes, which are attracting increasing interest, could represent a new approach to treat thrombosis by blocking the activity of PolyP with a potential anticoagulant activity and, most importantly, demonstrating no adverse bleeding events.

Retention of some heterocyclic amines on mixed stationary phases containing nickel(II) Schiff base chelates

1989 ◽  
Vol 54 (6) ◽  
pp. 1530-1537 ◽  
Author(s):  
Joanna Masłowska ◽  
Grzegorz Bazylak
Keyword(s):  
Schiff Base ◽  
Stationary Phases ◽  
Capillary Columns ◽  
Heterocyclic Amines ◽  
Complex Mixtures ◽  
Amine Complexes ◽  
Mixed Stationary Phases ◽  
Classical Columns

Stationary phases composed of squalane and some nickel(II)-β-keto amine complexes were prepared and used for the separation of complex mixtures of pyridines. The resolution achieved on short classical columns was comparable with that obtained on capillary columns.

Co(II) and Cu(II) Schiff base complexes of bis(N-(4-diethylamino-2-methylphenyl)-3,5-di-tert-butylsalicylaldimine): Electrochemical and X-ray structural study

2008 ◽  
Vol 19 (5) ◽  
pp. 749-755 ◽  
Author(s):  
Mahmut Ulusoy ◽  
Hasan Karabıyık ◽  
Rafet Kılınçarslan ◽  
Muhittin Aygün ◽  
Bekir Çetinkaya ◽  
...  
Keyword(s):  
Schiff Base ◽  
Structural Study ◽  
Schiff Base Complexes ◽  
X Ray

Unexpected isolation of a cyclohexenone derivative

2019 ◽  
Vol 74 (11-12) ◽  
pp. 819-824
Author(s):  
Jürgen Voss ◽  
Rüdiger Röske ◽  
Gunnar Ehrlich ◽  
Gunadi Adiwidjaja
Keyword(s):  
Structure Determination ◽  
Aldol Condensation ◽  
Knoevenagel Reaction ◽  
X Ray

AbstractKnoevenagel reaction of pivaloylacetone with formaldehyde and subsequent aldol condensation ends up with 3-methyl-4,6-dipivaloylcyclohex-2-enone. The structure of the product is proved by an X-ray structure determination.

Functional substituted Cu(II) Schiff base complexes, syntheses, X-ray and theoretical characterizations, and investigations of their polyphenol oxidase- and peroxidase-like activities

2021 ◽  
Vol 1232 ◽  
pp. 129975
Author(s):  
Murat Tuna ◽  
Salih Zeki Yildiz ◽  
Gulnur Arabaci ◽  
Zeynep Denli ◽  
Nagihan Çaylak Delibaş ◽  
...  
Keyword(s):  
Schiff Base ◽  
Polyphenol Oxidase ◽  
Schiff Base Complexes ◽  
X Ray

Synthesis, structural characterization and catalytic activity of chlororuthenium(II) complexes with substituted Schiff base/phosphine ancillary ligands

2020 ◽  
Vol 75 (9-10) ◽  
pp. 851-857
Author(s):  
Chong Chen ◽  
Fule Wu ◽  
Jiao Ji ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Structural Characterization ◽  
Room Temperature ◽  
Molecular Structures ◽  
Cationic Complex ◽  
Neutral Complex ◽  
Ancillary Ligands ◽  
X Ray ◽  
X Ray Crystallography

AbstractTreatment of [(η6-p-cymene)RuCl2]2 with one equivalent of chlorodiphenylphosphine in tetrahydrofuran at reflux afforded a neutral complex [(η6-p-cymene)RuCl2(κ1-P-PPh2OH)] (1). Similarly, the reaction of [Ru(bpy)2Cl2·2H2O] (bpy = 2,2′-bipyridine) and chlorodiphenylphosphine in methanol gave a cationic complex [Ru(bpy)2Cl(κ1-P-PPh2OCH3)](PF6) (2), while treatment of [RuCl2(PPh3)3] with [2-(C5H4N)CH=N(CH2)2N(CH3)2] (L1) in tetrahydrofuran at room temperature afforded a ruthenium(II) complex [Ru(PPh3)Cl2(κ3-N,N,N-L1)] (3). Interaction of the chloro-bridged complex [Ru(CO)2Cl2]n with one equivalent of [Ph2P(o-C6H4)CH=N(CH2)2N(CH3)2] (L2) led to the isolation of [Ru(CO)Cl2(κ3-P,N,N-L2)] (4). The molecular structures of the ruthenium(II) complexes 1–4 have been determined by single-crystal X-ray crystallography. The properties of the ruthenium(II) complex 4 as a hydrogenation catalyst for acetophenone were also tested.

scholarly journals 4-vinylpyridine derivatives: Protonation, methylation and silver(I) coordination chemistry

2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Coordination Chemistry ◽  
Elemental Analysis ◽  
Silver Complex ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Moiety ◽  
New Compounds

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.

scholarly journals Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

2021 ◽  
Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Structural Characterization ◽  
Schiff Base Ligand ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

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