4600-08-2Relevant articles and documents
Cu-Catalyzed C-H Allylation of Benzimidazoles with Allenes
Dong, Yaxi,Breit, Bernhard
, p. 6765 - 6769 (2021/09/11)
CuH-catalyzed intramolecular cyclization and intermolecular allylation of benzimidazoles with allenes have been described. The reaction proceeded smoothly with the catalytic system of Cu(OAc)2/Xantphos and catalytic amount of (MeO)2MeSiH. This protocol features mild reaction conditions and a good tolerance of substrates bearing electron-withdrawing, electron-donating, or electron-neutral groups. A new catalytic mechanism was proposed for this copper hydride catalytic system.
Thermodynamic Programming of Erbium(III) Coordination Complexes for Dual Visible/Near-Infrared Luminescence
Golesorkhi, Bahman,Guénée, Laure,Nozary, Homayoun,Fürstenberg, Alexandre,Suffren, Yan,Eliseeva, Svetlana V.,Petoud, Stéphane,Hauser, Andreas,Piguet, Claude
supporting information, p. 13158 - 13169 (2018/09/11)
Intrigued by the unexpected room-temperature dual visible/near-infrared (NIR) luminescence observed for fast-relaxing erbium complexes embedded in triple-stranded helicates, in this contribution, we explore a series of six tridentate N-donor receptors L4–L9 with variable aromaticities and alkyl substituents to extricate the stereoelectronic features responsible for such scarce optical signatures. Detailed solid-state (X-ray diffraction, differential scanning calorimetry, optical spectroscopy) and solution (speciations and thermodynamic stabilities, spectrophotometry, NMR and optical spectroscopy) studies of mononuclear unsaturated [Er(Lk)2]3+ and saturated triple-helical [Er(Lk)3]3+ model complexes reveal that the stereoelectronic changes induced by the organic ligands affect inter- and intramolecular interactions to such an extent that 1) melting temperatures in solids, 2) the affinity for trivalent erbium in solution, and 3) optical properties in luminescent complexes can be rationally varied and controlled. With this toolkit in hand, mononuclear erbium complexes with low stabilities displaying only NIR emission can be transformed into molecular-based dual Er-centered visible/NIR emitters operating at room temperature in both solid and solution states.
Amino Azaxylylenes Photogenerated from o-Amido Imines: Photoassisted Access to Complex Spiro-Poly-Heterocycles
Mukhina, Olga A.,Kuznetsov, Dmitry M.,Cowger, Teresa M.,Kutateladze, Andrei G.
supporting information, p. 11516 - 11520 (2015/11/03)
Upon irradiation, cyclic imines containing o-amido groups are shown to produce reactive intermediates, amino azaxylylenes, which undergo intramolecular cycloadditions to tethered unsaturated pendants to yield complex N,O-heterocycles having an additional spiro-connected nitrogen heterocyclic moiety. Modular assembly of the photoprecursors allows expeditious increase of the complexity of the target poly-heterocyclic scaffolds with a minimal number of experimentally simple reaction steps. The photocyclization and subsequent postphotochemical transformations are accompanied by an increase of Lovering's fsp3 factor, thus producing unprecedented three-dimensional molecular architectures, and offering extended sampling of chemical space. Rings in three dimensions: Cyclic imines containing an o-amido group undergo excited-state intramolecular proton transfer to generate amino azaxylylenes. The amino azaxylylenes undergo intramolecular cycloadditions to tethered unsaturated pendants to yield complex heterocyclic three-dimensional molecular architectures.
Discovery of small molecule benzimidazole antagonists of the chemokine receptor CXCR3
Hayes, Martin E.,Wallace, Grier A.,Grongsaard, Pintipa,Bischoff, Agnieszka,George, Dawn M.,Miao, Wenyan,McPherson, Michael J.,Stoffel, Robert H.,Green, David W.,Roth, Gregory P.
, p. 1573 - 1576 (2008/09/21)
High-throughput screening identified a low molecular weight antagonist of CXCR3 displaying micromolar activity in a membrane filtration-binding assay. Systematic modification of the benzimidazole core and tethered acetophenone moiety established tractable SAR of analogs with improved physicochemical properties and sub-micromolar activity across both human and murine receptors.
Synthesis and SAR of 2-arylbenzoxazoles, benzothiazoles and benzimidazoles as inhibitors of lysophosphatidic acid acyltransferase-β
Gong, Baoqing,Hong, Feng,Kohm, Cory,Bonham, Lynn,Klein, Peter
, p. 1455 - 1459 (2007/10/03)
2-Arylbenzoxazoles, benzothiazoles and benzimidazoles were identified as new classes of potent, isoform specific inhibitors of lysophosphatidic acid acyltransferase-β (LPAAT-β). Effects of selected inhibitors on proliferation of tumor cells in vitro were investigated.
Benzoxazole LPAAT-B inhibitors and uses thereof
-
, (2008/06/13)
The invention relates to benzoxazoles and the use thereof to inhibit lysophosphatidic acid acyltransferase β (LPAAT-β) activity. The invention further relates to methods of treating cancer using said benzoxazoles. The invention also relates to methods for screening for LPAAT-β activity.
Selective one-pot N-monomethylation of 2-nitroanilines under PTC conditions
Voskresensky,Makosza
, p. 3523 - 3526 (2007/10/03)
Direct PTC methylation of 2-nitroanilines with dimethyl sulfate gave selectively N-monomethylated products. A variety of N-methyl-2-nitroanilines were prepared in this way.
Thermal decomposition of arylnitramines
Naud, Darren L.
, p. 1321 - 1324 (2007/10/03)
The thermal decomposition of various substituted N-methyl-N-nitroanilines dissolved in indifferent solvents and piperidine has been investigated. Activation volumes and product analyses support evidence that the rate-determining step is the reversible homolysis of the nitramine bond. The activation volumes range from +18 to +36 ml mol-1. A non-linear Hammett relationship is attributed to an increase in secondary caged reactions, namely rearrangement and oxidation. Arylnitramines with electron-donating substituents yield greater amounts of the thermal rearrangement products than those with electron-deactivating groups at ambient pressures. Decomposition of arylnitramines with electron-donating substituents under high pressures (ca. 1.2 GPa) favours caged reactions over separative diffusion.
A 'one-pot' phase transfer alkylation/hydrolysis of o-nitrotrifluoroacetanilides. A convenient route to N-alkyl o-phenylenediamines
Brown, Samuel A.,Rizzo, Carmelo J.
, p. 4065 - 4080 (2007/10/03)
A variety of o-nitrotrifluoroacetanilides undergo a one-pot alkylation/hydrolysis to give N-alkyl o-nitroanilines in 40-94% yield. Dimethylsulfate, benzyl bromide and 1-bromo-propane were used as the electrophiles.
Intramolecular Hydrogen Bonding in Some ortho-Substituted N-Methyl-, N-Benzyl- and N-Aryl-4-nitroanilines: a Proton Magnetic Resonance Study
Wilshire, John F. K.
, p. 2497 - 2504 (2007/10/02)
1H n.m.r. spectra of a wide variety of N-methyl, N-benzyl and N-aryl 2-substituted 4-nitroanilines where the 2-substituent is an electron-withdrawing group, namely acetyl, cyano, formyl or methoxycarbonyl, reveal that long-range coupling (5J 0.65-0.70 Hz) occurs between the NH proton and the 5-proton of the nitroaryl ring in (D)chloroform solution; coupling is absent when the 2-substituent is trifluoromethyl.However, for some compounds (the nature of the 2-substituent is critical), NH,H5 coupling is absent in (D6)dimethyl sulfoxide solution.An examination of these phenomena leads to the conclusion (a) that intramolecular hydrogen bonding occurs between the NH group and the 2-substituent and (b) that, for these N,2-substituted 4-nitroanilines, the intramolecular hydrogen bond strength decreases in the following order: NH...COOCH3 > NH...NO2 ca.NH...COCH3 > NH...CHO > NH...CN A parallel study involving some N-methyl 4-substituted 2-nitroanilines where the 4-substituent is an electron-donating group, namely t-butyl, methyl and methoxy, revealed long-range NH,H5 coupling in both (D)chloroform and (D6)dimethyl sulfoxide solution; when the substituent is dimethylamino, NH,H5 coupling could not be detected in either solvent.
