Derivatives Bearing Research Articles

Anthracene Derivatives Bearing Thiourea and Glucopyranosyl Groups for the Highly Selective Chiral Recognition of Amino Acids: Opposite Chiral Selectivities from Similar Binding Units

Two new anthracene thiourea derivatives, 1 and 2, were investigated as fluorescent chemosensors for the chiral recognition of the two enantiomers of alpha-amino carboxylates. Especially, host 2 displayed K(L)/K(D) values as high as 10.4 with t-Boc alanine. Furthermore, the D/L selectivity of hosts 1 and 2 is opposite, even though both hosts bear the same glucopyranosyl units. These intriguing opposite D/L binding affinities by 1 and 2 were obtained without/with H-pi interaction between anthrancene moiety and the methyl groups, which were explained by extensive high-level theoretical investigations taking into account the dispersion energy as well as the 2D-NMR chemical shifts.

Synthesis and Liquid Crystalline Properties of Mono‐, Di‐ and Tri‐O‐alkyl Pentaerythritol Derivatives Bearing Tri‐, Di‐ or Monogalactosyl Heads: The Effects of Curvature of Molecular Packing on Mesophase Formation

Self-organisation and self-assembly are critical to the stability of synthetic and biological membranes. Of particular importance is consideration of the packing arrangements of the various molecular species. Both phospho- and glycolipids can pack in ways in which curvature can be introduced into self-organised or self-assembled systems. For instance, it is known that the degree of curvature can affect the structures of any condensed phases that are formed. In this article we report on a systematic study in which we have varied the shapes of glycolipids and examined the condensed phases that they form. In doing so, we have also unified the shape dependency of lyotropic liquid crystals with those of thermotropic liquid crystals. In order to undertake this systematic study a range of different pentaerythritol derivatives was synthesized, which covers combinations of one to three alkyl chains of different lengths (6,7,9,10,11,12,14,16 carbon atoms) and three to one galactosyl heads. Mono- and di-O-galactosyl derivatives were prepared directly by glycosylation of the corresponding alcohols using 2,3,4,6-tetra-O-benzoyl or acetyl-alpha-D-galactopyranosyl trichloroacetimidate or bromide as the donors; the tri-O-galactosyl derivatives were synthesized from O-alkyl-O-benzyl di-O-galactosyl pentaerythritol intermediates, followed by de-O-benzylation and glycosylation steps. All of the fully deprotected products were obtained by standard methods, and their self-organising and self-assembling properties examined.

Synthesis and Oxidation of Triarylamine Derivatives Bearing Hydrogen-Bonding Groups

Hydrogen-bonding triarylamines, 4-(N,N-bis(4-methoxyphenyl)amino)benzoic acid (TPA1), 5-(N,N-bis(4-methoxyphenyl)amino)isophthalic acid (TPA2), and N-(4-(1H-benzimidazol-2-yl)phenyl)-N,N-bis(4-methoxyphenyl)amine (BImTPA), were synthesized as radical cation precursors. TPA1 and TPA2 are readily p-doped by AgSbF(6) to give highly persistent radical cations. Poor solid-state spin yields of the radical cation from BImTPA may be due to spin delocalization.

Design, Synthesis and Cu2+ Recognition ofβ-Diketoacid and Quinoxalone Derivatives Bearing Caffeoyl or Galloyl Moieties Linked by Arylamide as Potential HIV Integrase Inhibitors

An efficient procedure for the synthesis of caffeoyl- and galloyl-containing β-diketoacid derivatives linked by arylamide was reported by, in the key step, dissolving the corresponding phenyl methyl ketone in THF/DME in the presence of NaOMe as base and dimethyl oxalate as oxalylation reagent, and then separating the sodium ketoenolate ester. The resulting β-diketoacids underwent further condensation reaction with o-phenylenediamine to generate quinoxalone derivatives in good yield, rather than 2-benzimidazol. The preliminary ion binding properties of quinoxalone derivatives were also investigated. UV-Vis spectra showed that these compounds could selectively recognize Cu2+ ion in ethanol and form a 1:2 complex.

Benzimidazole Derivatives Bearing Substituted Biphenyls as Hepatitis C Virus NS5B RNA-Dependent RNA Polymerase Inhibitors: Structure−Activity Relationship Studies and Identification of a Potent and Highly Selective Inhibitor JTK-109

Following the discovery of a new series of benzimidazole derivatives bearing a diarylmethyl group as inhibitors of hepatitis C virus NS5B RNA-dependent RNA polymerase (HCV NS5B RdRp),1,2 we extended the structure-activity relationship (SAR) study to analogues bearing a substituted biphenyl group and succeeded in a significant advancement of activity. Starting from compound 1, optimization of the A, B, and C rings afforded potent inhibitors with low nanomolar potency against genotype 1b NS5B. The compounds, which have a substituent with a carbonyl function at the 4-position of the B-ring, efficiently blocked subgenomic viral RNA replication in the replicon cell assay at low submicromolar concentrations. Among the new compounds, compound 10n (JTK-109) exhibited favorable pharmacokinetic profiles, high selectivity for NS5B, and good safety profiles, suggesting the potential for a clinical candidate in the treatment of hepatitis C.

Supramolecular Complexes Obtained from Porphyrin—Crown Ether Conjugates and a Fullerene Derivative Bearing an Ammonium Unit.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Controlled Synthesis and Inclusion Ability of a Hyaluronic Acid Derivative Bearing β-Cyclodextrin Molecules

A new synthetic route to beta-cyclodextrin-linked hyaluronic acid (HA-CD) was developed. This was based on the preparation of a HA derivative selectively modified with adipic dihydrazide (HA-ADH) and a beta-cyclodextrin derivative possessing an aldehyde function on the primary face, followed by their coupling by a reductive amination-type reaction. The CD-polysaccharide was fully characterized in terms of chemical integrity and purity by high-resolution NMR spectroscopy. The complexation ability of the grafted CD was further demonstrated by isothermal titration calorimetry using sodium adamantane acetate (ADAc) and Ibuprofen as model guest molecules. The thermodynamic parameters for the complexation of these negatively charged guest molecules by the beta-CD grafted on negatively charged HA were shown to be largely influenced by the ionic strength of the aqueous medium.

Synthesis of New Conjugated Polyfluorene Derivatives Bearing Triphenylamine Moiety through a Vinylene Bridge and Their Stable Blue Electroluminescence

Two new conjugated polyfluorene derivatives bearing triphenylamine moiety through a vinylene bridge, PDPF and PBPF, have been successfully synthesized according to the Suzuki coupling method. The structures and properties of the monomers and the resulting conjugated polymers were characterized by using 1H NMR, 13C NMR, FT-IR, elemental analysis, GPC, TGA, DSC, UV−vis absorption spectroscopy, photoluminescence (PL) spectroscopy, and cyclic voltammetry (CV). The obtained polymers possess excellent solubility in common organic solvents, good thermal stability with 5% weight loss temperature of 415−448 °C, and relatively high glass transition temperature (Tg) at about 91−159 °C. The weight-average molecular weight (Mw) of PDPF and PBPF were 5.79 × 104 and 1.68 × 104 with the polydispersity index (PDI) of 2.75 and 2.69, respectively. The two-dimensional conjugated system of PFs can effectively suppress π-stacking/aggregation, improve hole injection, and facilitate intramolecular energy transfer. Single-layer P...

Direct Synthesis of Monofunctionalized Indolizine Derivatives Bearing Alkoxymethyl Substituents at C‐3 and Their Benzofused Analogues.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Direct Synthesis of Monofunctionalized Indolizine Derivatives Bearing Alkoxymethyl Substituents at C-3 and Their Benzofused Analogues

[reaction: see text] Treatment of (Z)-2-pyridine and quinoline silylated vinylacetylenes at reflux with several alcohols in the presence of a suitable inorganic base (KOH, K2CO3, CsF, or KF) serendipitously gave 3-alkoxylmethylindolizines and the corresponding 1-alkoxymethylpyrrolo [1,2-a]quinolines and not the anticipated desilylated vinylacetylene derivatives. A mechanistic possibility for this unexpected chemical transformation is suggested.

Crystal Structures of Lanthanide(III) Complexes with Cyclen Derivative Bearing Three Acetate and One Methylphosphonate Pendants

A series of lanthanide(III) complexes formulated as M[Ln(Hdo3ap)].xH(2)O (M = Li or H and Ln = Tb, Dy, Er, Lu, and Y) with the monophosphonate analogue of H(4)dota, 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic-10-methylphosphonic acid (H(5)do3ap), was prepared in the solid state and studied using X-ray crystallography. All of the structures show that the (Hdo3ap)(4-) anion is octadentate coordinated to a lanthanide(III) ion similarly to the other H(4)dota-like ligands, i.e., forming O(4) and N(4) planes that are parallel and have mutual angle smaller than 3 degrees . The lanthanide(III) ions lie between these planes, closer to the O(4) base than to the N(4) plane. All of the structures present the lanthanide(III) complexes in their twisted-square-antiprismatic (TSA) configuration. Twist angles of the pendants vary in the range between -24 and -30 degrees, and for each complex, they lie in a very narrow region of 1 degree. The coordinated phosphonate oxygen is located slightly above (0.02-0.19 Angstroms) the O(3) plane formed with the coordinated acetates. A water molecule was found to be coordinated only in the terbium(III) and neodymium(III) complexes. The bond distance Tb-O(w) is unusually long (2.678 Angstroms). The O-Ln-O angles decrease from 140 degrees [Nd(III)] to 121 degrees [Lu(III)], thus confirming the increasing steric crowding around the water binding site. A comparison of a number of structures of Ln(III) complexes with DOTA-like ligands shows that the TSA arrangement is flexible. On the other hand, the SA arrangement is rigid, and the derived structural parameters are almost identical for different ligands and lanthanide(III) ions.

Synthesis and Antibacterial Activities of Novel Biphenyltetrazole Derivatives Bearing 1,3,4-Oxadiazole

Several new 5-[4′-(5-phenyl-1,3,4-oxadiazol-2-ylsulfanylmethyl)-biphenyl-2-yl]-tetrazoles derivatives have been synthesized. The structures of these new compounds were confirmed by elementary analyses and spectral data. The antibacterial activities of the compounds were also evaluated.

New Benzylpiperazine Derivatives Bearing Mono‐ and Bis‐Dialkyl Substituted 1,2,4‐Triazoles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Fluoride Ion Receptors Based on Dipyrrolyl Derivatives Bearing Electron-Withdrawing Groups: Synthesis, Optical and Electrochemical Sensing, and Computational Studies

Two dipyrrolyl derivatives, 2,3-di(1H-2-pyrrolyl)-7,12-dihydronaphtho[2,3-f]quinoxaline-7,12-dione (1) and 5,6-di(1H-2-pyrrolyl)-2,3-pyrazine-dicarbonitrile (2), bearing electron-withdrawing quinone or dicyano subunits, have been synthesized and fully characterized by various spectroscopic and electrochemical methods. Both 1 and 2 are specific binders of F- in organic solvents and show dramatic, binding-induced changes in their color (observable in the naked-eye experiments) and also optical and electrochemical signatures. These F--induced color changes remain the same even in the presence of a large excess of Cl-, Br-, I-, or ClO4-, thus rendering 1 and 2 to be efficient fluoride ion sensors. While Ka for F- binding by receptor 1 is ∼1.6 × 104 M-1, that for receptor 2 is an order of magnitude higher. 1H NMR titrations were carried out to monitor the binding of 1/2 with F-. These experiments not only provide evidence for the hydrogen-bonding interaction between the pyrrolic NH groups of these receptors an...

Synthesis and Biological Activities of Some Quinoxaline Derivatives Bearing Aromatic Halogen Nucleus.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis and Properties of Polymers from Monosubstituted Acetylene Derivatives Bearing Ferroelectric Liquid Crystalline Groups

Novel liquid crystalline polyacetylene derivatives were developed as advanced LC conjugated polymers with quick response to an electric field used as external force. In practice, we synthesized ferroelectric LC conjugated polymers by introducing fluorine-containing chiral LC groups into side chains of polyacetylenes. Phase-transition behaviors of these polymers were examined by differential scanning calorimetry and polarizing optical microscopy. Mesophases as well as higher order structures were evaluated with X-ray diffraction measurements. The polymers synthesized showed chiral nematic (N*), twist grain boundary smectic A (TGBA*), and chiral smectic (SmC*) phases in the heating and cooling processes. Observation of the SmC* phase allows us to expect that the polymer should exhibit ferroelectricity.

Oligochitosan derivatives bearing electron-deficient aromatic rings for adsorption of amitriptyline: implications for drug detoxification.

The objective of this work is the synthesis of water-soluble oligochitosan derivatives with electron deficient aromatic rings for selective and rapid adsorption of amitriptyline through pi-pi complexation. Oligochitosan was chemically modified under homogeneous conditions in dimethyl sulfoxide (DMSO). (1)H NMR, FT-IR, and MALDI-TOF were employed in characterization, confirming that the electron deficient aromatic rings were chemically attached to the backbone of oligochitosan. Thromboelastography (TEG) revealed functionalized oligochitosan derivatives did not affect blood clotting. (1)H NMR was also utilized to observe the aromatic-aromatic interaction between electron deficient aromatic rings on oligochitosan and electron rich aromatic rings in amitriptyline. The chemical shift variation of aromatic protons in oligochitosan derivatives was followed to monitor the aromatic-aromatic interaction. Upfield shift of aromatic protons on benzenesulfonyl and dinitrobenzenesulfonyl groups was observed upon the addition of amitriptyline, supporting the formation of pi-pi complexes through aromatic-aromatic interactions. Dinitrobenzenesulfonyl rings show a larger variation in chemical shift due to the presence of the electron deficient nitro groups.

Anionic Polymerization of Novel Styrene Derivatives Bearing Various Amino Groups at ortho-Position

The novel styrene derivatives bearing various amino groups at ortho-position, 2-(1-indolinyl)methylstyrene (2), 2-(9-carbazolyl)methylstyrene (3), 2-(N,N-diphenylamino)methylstyrene (4), 2-(N-3-methoxyphenyl-N-phenylamino)methylstyrene (5), and 2-(N-3-methylphenyl-N-phenylamino)methylstyrene (6), were synthesized and polymerized with radical and anionic initiations. As the bulkiness of the substituents at the ortho-position increased, the polymerizabilities of these monomers during the radical and anionic methods significantly decreased. The anionic polymerization of 4–6 with the n-butyllithium (−)-sparteine complex in toluene at 0 °C afforded the optically active polymers ([α]25365 +48° to +22°), whereas no optical activity was observed for the polymers of 2 and 3 obtained under the same conditions. The optically active polymers likely have a chiral helical conformation which is related to a high stereoregularity.

Fentanyl Derivatives Bearing Aliphatic Alkaneguanidinium Moieties: A New Series of Hybrid Molecules with Significant Binding Affinity for μ‐Opioid Receptors and I2‐Imidazoline Binding Sites.

A new series of fentanyl derivatives [i.e., N-[1-(2-phenethyl)-4-piperidyl]-N-(guanidinoalkyl)propanamide] bearing aliphatic alkaneguanidinium moieties were prepared. Their affinities for the micro opioid receptors and for the I(2)-imidazoline binding sites (I(2)-IBS) were determined on human post-mortem prefrontal cortex membranes. All of these hybrid compounds had significant and/or very high affinity for both receptors in the nanomolar range, meaning an improvement compared to the prototype N-[1-(2-phenethyl)-4-piperidyl]-N-(guanidinopropyl)propanamide previously reported.

Synthesis of a Pentaerythritol Derivative Bearing Azo Functions.

AbstractFor Abstract see ChemInform Abstract in Full Text.