- Structural and ethylene oligomerization studies of chelated N?O (imino/amino)phenol nickel(II) complexes
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Condensation reactions of 2-aminoethanol with the appropriate aldehyde gave ligands 2-[1-[(2-hydroxyethyl)imino]ethyl]phenol (L1) and 2-[(2-hydroxyethyl)imino] methyl]phenol (L2) respectively. Subsequent reductions of L1 and L2 with NaBH4 affor
- Ngcobo, Makhosonke,Ojwach, Stephen O.
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- Salicylaldehyde-(2-hydroxyethyl)imine - A flexible ligand for group 13 and 14 elements
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The reaction of salicylaldehyde-(2-hydroxyethyl)imine (H2L), 1, with organoelement halides from group 13 and 14 leads to a variety of coordination compounds. Depending on the size of the central atom and the organic substituents, tetra-, penta- or hexacoordinated complexes emerge. When the central atom of the complex has a small atom radius and small substituents, like methyl groups, coordination number four is preferred. Thereby macrocyclic compounds of the composition L2(SiMeR)2 (R = Me, cyclohexyl) are formed. With phenyl substituted element halides Ph2ECl2 pentacoordinated complexes LEPh2 (E = Si, Ge, Sn) were isolated. Hexacoordinated complexes of the composition L2E (E = Si, Sn) were obtained from ECl4 and 1. A surprising result was obtained from the reaction of 1 with InCl3. The resulting complex is a monoanionic trimer, obeying the composition [HNEt3][L3In3Cl3(μ3-OH)].(DME)2(THF) in the solid state structure. The prepared compounds were characterised by NMR and IR spectroscopy, elemental and X-ray structure analysis. Furthermore solid state NMR measurements and chemical shift tensor analysis with the help of quantum chemical methods were used to analyse the electron density distribution around the central atoms of several products. The results of this study demonstrate the structural variety that can be created with a single O,N,O' chelating ligand.
- Paul, Lydia E.H.,Foehn, Ines C.,Schwarzer, Anke,Brendler, Erica,B?hme, Uwe
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- Heterometallic CoIII4FeIII2 schiff base complex: Structure, electron paramagnetic resonance, and alkane oxidation catalytic activity
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The heterometallic complex [Co4Fe2OSae 8]·4DMF·H2O (1) was synthesized by one-pot reaction of cobalt powder with iron chloride in a dimethylformamide solution of salicylidene-2-ethanolamine (H2Sae) and characterized by single crystal X-ray diffraction analysis, magnetic measurements, high frequency electron paramagnetic resonance (HF-EPR), and Moessbauer spectroscopies. The exchange coupling in the Fe(III)-Fe(III) pair is of antiferromagnetic behavior with J/hc = -190 cm-1. The HF-EPR spectra reveal an unusual pattern with a hardly detectable triplet signal of the Fe(III) dimer. The magnitude of D (ca. 13.9 cm-1) was found to be much larger than in related dimers. The catalytic investigations disclosed an outstanding activity of 1 toward oxidation of cycloalkanes with hydrogen peroxide, under mild conditions. The most efficient system showed a turnover number (TON) of 3.57×10 3 with the concomitant overall yield of 26% for cyclohexane, and 2.28×103/46%, respectively, for cyclooctane. A remarkable turnover frequency (TOF) of 1.12×104 h-1 (the highest initial rate W0 = 3.5×10-4 M s-1) was achieved in oxidation of cyclohexane. Kinetic experiments and selectivity parameters led to the conclusion that hydroxyl radicals are active (attacking C-H bonds) species. Kinetic and electrospray ionization mass spectrometry (ESI-MS) data allowed us to assume that the trinuclear heterometallic particle [Co2Fe(Sae)4]+, originated from 1 in solution, could be responsible for efficient generation of hydroxyl radicals from hydrogen peroxide.
- Nesterov, Dmytro S.,Pombeiro, Armando J. L.,Chygorin, Eduard N.,Kokozay, Volodymyr N.,Bon, Volodymyr V.,Boca, Roman,Kozlov, Yuriy N.,Shul'Pin, Georgiy B.,Shul'Pina, Lidia S.,Jezierska, Julia,Ozarowski, Andrew
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- Solvent-induced structural transformation from heptanuclear to decanuclear [Co-Ln] coordination clusters: trapping of unique counteranion and understanding of aggregation pathways
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Five new cobalt(ii/iii)-lanthanide(iii)-based coordination aggregates, [LnIII3CoII2CoIII2(L1)2(O2CCMe3)8(OH)4(OMe)2(H2O)4]·Ln(η1-O2CCMe3/su
- Basak, Dipmalya,Martí, Emma Regincós,Murrie, Mark,Nemec, Ivan,Ray, Debashis
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- Details make the difference: A family of tetranuclear CuIIMnIII complexes with cube-like and double open cube-like cores
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The "direct synthesis" approach, namely one-pot reaction of metal powders and ammonium salt with a methanol solution of a polydentate Schiff base (H2L) formed in situ from salicylaldehyde and ethanolamine, has been successfully used for the pre
- Stetsiuk, Oleh,Nesterova, Oksana V.,Kokozay, Vladimir N.,Domasevitch, Kostiantyn V.,Omelchenko, Iryna V.,Shishkin, Oleg V.,Vranovi?ová, Beata,Bo?a, Roman,Pombeiro, Armando J. L.,Petrusenko, Svitlana R.
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- An oxorhenium(V) Schiff-base complex: Synthesis, structure, spectroscopic characterization, electrochemistry, and DFT calculations
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Reaction of the Schiff base 2-[(2-hydroxyethylimino)methyl]phenol (H 2L) with trans-ReOCL3(PPh3)2 in 1 : 1M ratio in dichloromethane gives [ReOCL2(HL)(PPh3)] (1) in substantial yield. The compound has been chara
- Majumder, Smita,Naskar, Jnan Prakash,Banerjee, Snehasis,Bhattacharya, Arnab,Mitra, Partha,Chowdhury, Shubhamoy
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- Synthetic diversity and change in nuclearity in [Co-Dy] coordination aggregates: bridge removal, solvent induced structural reorganization and AC susceptibility measurements
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Three new cobalt(ii/iii)-dysprosium(iii) complexes, [DyII3CoI2CoII2(L1)2(O2CCMe3)8(OH)4(OMe)2(H2O)4]·Dy(η1-O2CCMe3)2(η
- Basak, Dipmalya,Gupta, Tulika,K?gerler, Paul,Ray, Debashis,van Leusen, Jan
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p. 7576 - 7591
(2020/06/21)
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- Discovery of clinical candidate (1 R,4 r)-4-((R)-2-((S)-6-Fluoro-5 H-imidazo[5,1-A[isoindol-5-yl)-1-hydroxyethyl)cyclohexan-1-ol (Navoximod), a potent and selective inhibitor of indoleamine 2,3-dioxygenase 1
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A novel class of 5-substituted 5H-imidazo[5,1-a]isoindoles are described as potent inhibitors of indoleamine 2,3-dioxygenase 1 (IDO1). A structure-based drug design approach was used to elaborate the 5H-imidazo[5,1-a]isoindole core and to improve potency and pharmacological properties. Suitably placed hydrophobic and polar functional groups in the lead molecule allowed improvement of IDO1 inhibitory activity while minimizing off-target liabilities. Structure-activity relationship studies focused on optimizing IDO1 inhibition potency and a pharmacokinetic profile amenable to oral dosing while controlling CYP450 and hERG inhibitory properties.
- Kumar, Sanjeev,Waldo, Jesse P.,Jaipuri, Firoz A.,Marcinowicz, Agnieszka,Van Allen, Clarissa,Adams, James,Kesharwani, Tanay,Zhang, Xiaoxia,Metz, Richard,Oh, Angela J.,Harris, Seth F.,Mautino, Mario R.
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p. 6705 - 6733
(2019/08/20)
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- Hydrogenation of alkenes and alkynes catalysed by N?O (imino)phenol palladium(II) complexes: Structural, kinetics and chemoselectivity studies
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Reactions of 2-(2-methoxyethylimino)ethyl)phenol (HL1), 2-(2-hydroxyethylimino)ethyl)phenol (HL2), 2-(2-aminoethylimino)ethyl)phenol (HL3) and 2-(2-hydroxyethylimino)methyl)phenol (HL4) with [PdCl2(COD)] afforded the neutral palladium complexes [PdCl2(HL1)] (1), [PdCl2(HL2)] (2), [PdCl2(HL3)] (3), [PdCl2(HL4)] (4) respectively. Treatment of complex 1 with PPh3 gave the cationic complex [Pd(HL1)ClPPh3]+ (5), while reactions of 4 with Pd(OAc)2, in the presence of PPh3 and p-TsOH produced the corresponding palladium complex, [Pd(L1) (OTs) (PPh3)] (6). The molecular structure of 4a (derivative of 4) contained two bidentate anionic ligands (L4). Complexes 1–6 formed active catalysts in hydrogenation of alkenes and alkynes, in which the catalytic activities were largely dependent on the pendant donor atom of the ligand motif. Isomerization reactions were dominant in terminal alkenes hydrogenation reactions, while hydrogenation of alkynes to alkanes occurred in two steps via alkene intermediates. Kinetics data were consistent with homogeneous active species. Density functional theory studies supported the hemi-labile nature of the ligands, and offered insights into the catalytic activity trends observed.
- Tshabalala, Thandeka A.,Ojwach, Stephen O.
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- A Schiff base zinc compound, preparation method thereof and method for producing polylactic acid
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The invention provides a schiff base zinc compound which is in a structure as shown in Formula 1, wherein R1 and R2 are independently selected from -H, alkyl, halogen and -NO2; R3, R4 and R5 are independently selected from -H and -CH3; R' is alkoxyl or -O
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Paragraph 0086; 0087; 0088
(2017/10/27)
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- Metal-based ethanolamine-derived compounds: a note on their synthesis, characterization and bioactivity
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Metal-based ethanolamines, (L1)–(L4) coordinated with Co(II), Cu(II), Ni(II) and Zn(II) metals in 1:2 (metal:ligand) molar ratio to produce new compounds have been reported. These compounds were screened for their bactericidal/fungic
- Amjad, Muhammad,Sumrra, Sajjad H.,Akram, Muhammad Safwan,Chohan, Zahid H.
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- An efficient microwave method for the synthesis of imines
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A large variety of aryl and heterocyclic chiral and achiral imines can be generated simply, efficiently, and cleanly through the use of microwave irradiation and the use of a small amount of molecular sieve. Reactions are rapid and complete in a matter of minutes, and can be quantitative, reducing significantly the time and amount of solvents used in compound isolation and purification.
- Border, Emily C.,Blair, Victoria L.,Andrews, Philip C.
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p. 844 - 848
(2015/05/20)
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- IDO inhibitors
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Presently provided are compounds according to the formula (I) or (II), and pharmaceutical compositions comprising the compounds, wherein R1, R4, and R5 are defined herein. Such compounds and compositions are useful for mod
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Page/Page column 214
(2015/11/27)
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- Salicylaldehyde-(2-hydroxyethyl)imine - A flexible ligand for group 13 and 14 elements
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The reaction of salicylaldehyde-(2-hydroxyethyl)imine (H2L), 1, with organoelement halides from group 13 and 14 leads to a variety of coordination compounds. Depending on the size of the central atom and the organic substituents, tetra-, penta-
- Paul, Lydia E.H.,Foehn, Ines C.,Schwarzer, Anke,Brendler, Erica,B?hme, Uwe
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p. 268 - 280
(2015/02/19)
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- Non-oxidative vanadium-catalyzed co bond cleavage: Application to degradation of lignin model compounds
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(Chemical Equation Presented) New direction: Changes In the ligand structure divert the reactivity of vanadium (V) oxo complexes from alcohol oxidation to a novel non-oxidative C-O bond cleavage. Thus, highly functionalized aryl enones can be selectively generated from lignin model compounds by vanadium-catalyzed cleavage of the β-O-4 linkage (see scheme; N blue, O red).
- Son, Sunghee,Toste, F. Dean
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supporting information; experimental part
p. 3791 - 3794
(2010/08/22)
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- Oxo-bridged bis oxo-vanadium(V) complexes with tridentate Schiff base ligands (VOL)2O (L = SAE, SAMP, SAP): Synthesis, structure and epoxidation catalysis under solvent-free conditions
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The dinuclear V(V) complexes (VOL)2O (L = SAE (1), SAMP (2), SAP (3)) have been synthesized from VO(acac)2 and the corresponding tridentate ligands LH2 in methanol under reflux conditions and subsequent air oxidation in organic solvent. They have been characterized by IR and NMR spectroscopy, by thermogravimetric analysis, and by single crystal X-ray diffraction for 1 and 2. DFT calculations were carried out for a better understanding of the vibrational pattern, principally the V-O related vibrations. Complex [VO(SAP)]2O (3) catalyzes the epoxidation of cyclooctene by TBHP in water in the absence of any added solvent with good selectivity.
- Cordelle, Cindy,Agustin, Dominique,Daran, Jean-Claude,Poli, Rinaldo
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body text
p. 144 - 149
(2011/02/23)
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- Study of the Reaction of Tridentate Ligands with Ferrocenyl Boronic Acid
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Evaluation of the reactivity of eight tridentate ligands derived from amino alcohols and salicylaldehyde, 2-hydroxyacetophenone, or 2-hydroxybenzophenone with ferrocenyl boronic acid has shown that the reaction leads to both monomeric and dimeric ferrocen
- Barba, Victor,Xochipa, Rubi,Santillan, Rosa,Farfan, Norberto
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p. 118 - 124
(2007/10/03)
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- Agent for coloring fibers and method for temporarily coloring fibers
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The object of the present invention is a preparation for coloring fibers, which is prepared before use by mixing an acidic component (A1), containing at least one enamine of Formula (I)/(Ia) with a component (A2), containing a Schiff's base of Formula (II
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- Fixed stereochemical control in the synthesis of new mono- and disubstituted 2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononenes
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Five new boronates of the type 2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononenes (6a-e) were prepared from substituted 2-[(2-hydroxyethylamino)methyl]phenols (4a-e) and phenylboronic acid (5) in benzene-EtOH (4:1) mixtures. Tridentate ligands 4a-e and boronates 6a-e were characterized by 1H, 13C, 15N, and 2D-NMR (HETCOR, NOESY, and COLOC) experiments, FT-IR, mass spectra, and elemental analysis, as well as 11B NMR for the boron derivatives. Suitable monocrystals of 2-[(2-hydroxyethylamino)methyl]phenol hydrochloride (4a), cis-2-phenyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6a), (2S,5R,6S)-2,5-diphenyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6b), and (2S,4R,5R,6S)-2,4-diphenyl-5-methyl-6-aza-1,3-dioxa-2-borabenzocyclononene (6e) were obtained and their structures are discussed. The X-ray structures of 6a, 6b, and 6e, as well as the NMR data established that the configurations at the nitrogen and boron atoms are both "S" and the transannular fusion is cis. A semi-empirical (SAM1) study was used to calculate the energy for all possible stereoisomers, showing that the stabilization increases as the THC (tetrahedral character of the boron atom) increases and also as the N→B bond distance decreases, in agreement with the experimental results and previous work related to amino acid boronates.
- Beltran, Hiram I.,Alas, S. Jesus,Santillan, Rosa,Farfan, Norberto
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p. 801 - 812
(2007/10/03)
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- New perspectives for boronic esters in macrocyclic chemistry
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In the present contribution a tetrameric macrocyclic compound derived from 2,6-pyridinedimethanol and 3-nitrophenyl boronic acid, as well as 10 new dimeric boronates prepared from 2-salicylideneaminoethanol and different aryl boronic acids such as a 2-met
- Farfan, Norberto,Hoepfl, Herbert,Barba, Victor,Ochoa, Ma. Eugenia,Santillan, Rosa,Gomez, Elizabeth,Gutierrez, Atilano
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