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New Synthetic Route (new + synthetic_route)
Selected AbstractsA New Synthetic Route to Unsymmetrical 9-Arylxanthenes,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2009Sajal Kumar Das Abstract A facile and general three-step synthetic route towards unsymmetrical 9-arylxanthenes was developed. The reaction sequence involves nucleophilic substitution of commercially available 2-fluorobenzaldehydes with arenoxides, Grignard reaction of the resulting 2-arenoxybenzaldehydes with arylmagnesium bromides, followed by FeCl3 -catalyzed intramolecular diarylmethylation of the resulting carbinols. This strategy was extended to access symmetrical as well as unsymmetrical 9-arylthioxanthenes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Asymmetric 1,4-Addition of Organoboron Reagents to Quinone Monoketals Catalyzed by a Chiral Diene/Rhodium Complex: A New Synthetic Route to Enantioenriched 2-AryltetralonesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4-5 2007Norihito Tokunaga Abstract A novel synthetic approach to 2-aryltetralones with high ee has been developed through asymmetric 1,4-addition of arylboronic acids to naphthoquinone monoketals catalyzed by a rhodium complex with the (R,R)-Ph-bod* ligand. The asymmetric addition proceeded in high yields with excellent enantioselectivity. [source] Superacid-Catalyzed Hydroxyalkylation of Aromatics with Ethyl Trifluoropyruvate: A New Synthetic Route to Mosher,s Acid Analogues.CHEMINFORM, Issue 29 2003G. K. Surya Prakash Abstract For Abstract see ChemInform Abstract in Full Text. [source] New Synthetic Route to 2-(Diethylphosphono)-2H-azirines.CHEMINFORM, Issue 52 2002Valery K. Brel Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A New Synthetic Route to Aryl Hydroxysulfonamides via a Novel Fries-Type Rearrangement of Aryl N,N-Dialkylsulfamates.CHEMINFORM, Issue 9 2002G. Anthony Benson Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Development of a New Synthetic Route of a Non-Peptide CCR5 Antagonist, TAK-779, for Large-Scale Preparation.CHEMINFORM, Issue 15 2001Tomomi Ikemoto Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] New synthetic route towards 2,2-dimethylchromene and synthesis of substituted 7-(dimethylpropargyl)chromeneJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2008Babak H. Alizadeh Trifluoromethansufonic acid (TFA) was found a proper reagent for regioselectively ring closure of resorcinol to afford 7-hydroxy-2,2-dimethyl-2,3-dihydrochromen-4-one 3. The propargylation of 3 gave rise to 2,2-dimethyl-7-(2-methylbut-3-yn-2-yloxy)-2,3-dihydrochromen-4-one 4. Condensation of 4 with substituted phenyl or benzyl Grignard reagents afforded substituted phenyl or benzylidene chromenes 6a-d and 4-(substitutedbenzylidene)-3,4-dihydro chromenes 8a-e, respectively. [source] Structural Characterization and a New One-Pot Synthesis of trans -Chloro(phenyl)bis(triphenylphosphane)nickel(II)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2003Alexander Zeller Abstract trans -[NiCl(Ph)(PPh3)2], the organometallic precursor for a new class of neutral polymerization catalysts, has been synthesized via a new synthetic route. The previously used alkylaluminum compounds are replaced by zinc dust for the reduction of the nickel(II) salt in the presence of triphenylphosphane forming the intermediate Ni(PPh3)4. In a one-pot reaction, chlorobenzene then adds oxidatively to the intermediate to form the title compound, which was structurally characterized, in high yields. Its geometry is compared to known structures of the higher homologues of group 10. All complexes adopt a distorted square-planar geometry, but the parent structure shows significantly shorter metal-ligand bond lengths than its Pd and Pt congeners, as expected. Density functional theory calculations (B3LYP/6,31G*) on the full structure are in very good agreement with the solid-state structure. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Stereoselective Synthesis of (2S,4R)-4-Hydroxypipecolic AcidEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2008Ernesto G. Occhiato Abstract A new synthetic route to enantiopure (2S,4R)-4-hydroxypipecolic acid from commercial ethyl (3S)-4-chloro-3-hydroxybutanoate is reported. The synthesis is based on the Pd-catalyzed methoxycarbonylation of a 4-alkoxy-substituted ,-valerolactam-derived vinyl triflate followed by the stereocontrolled hydrogenation of the enamine double bond. The final product was obtained after exhaustive hydrolysis in 20,% yield over 10 steps. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Metal-Free Alkyne Polyhydrothiolation: Synthesis of Functional Poly(vinylenesulfide)s with High Stereoregularity by Regioselective Thioclick PolymerizationADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Cathy K. W. Jim Abstract A new synthetic route to sulfur-rich polymers has been developed. The alkyne polyhydrothiolations of 4,4,-thiodibenzenethiol (1) and arylene dipropiolates (2,5) mediated by amines proceed at room temperature in a regioselective fashion, furnishing sole anti-Markovnikov products of poly(vinylenesulfide)s (P1/2,P1/5) with high molecular weights (Mw up to 32 300) and high stereoregularities (Z content up to 81.4%) in high yields (up to 98.2%). Polymers P1/2,P1/4 are soluble in common organic solvents. They are optically transparent, allowing almost all visible and IR light to transmit through. Thanks to the high sulfur contents of the polymers, their films show high refractive indices (n,=,1.73,1.70) in the wavelength region of 500,1700 nm as well as high Abbé numbers (,D' up to 539) and low optical dispersions (D' down to 0.002) at wavelengths important for telecommunications. Their refractivities can be further enhanced (n up to 2.06) by metal complexation and their films can be crosslinked by UV irradiation, which enables ready fabrication of fluorescent photopatterns. [source] A Novel Method for the Synthesis of Substituted Benzochromenes by Ethylenediamine Diacetate-Catalyzed Cyclizations of Naphthalenols to ,,, -Unsaturated Aldehydes.HELVETICA CHIMICA ACTA, Issue 12 2007Concise Synthesis of the Natural Products Lapachenole, Dihydrolapachenole, Mollugin Abstract A new synthetic route for biologically interesting benzochromenes was developed starting from naphthalenols and ,,, -unsaturated aldehydes in the presence of ethylenediamine diacetate. This methodology was applied for the total synthesis of the biologically important natural products lapachenole, dihydrolapachenole, and mollugin with a benzochromene moiety. [source] ,Click' Dendritic Phosphines: Design, Synthesis, Application in Suzuki Coupling, and Recycling by NanofiltrationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009Michèle Janssen Abstract A new synthetic route towards stable molecular-weight enlarged monodentate phosphine ligands via ,click' chemistry was developed. These ligands were applied in the Pd-catalyzed Suzuki,Miyaura coupling of aryl halides and phenyl boronic acid. The supported systems show very similar activities compared to the unsupported analogues. Moreover, recycling experiments by means of nanofiltration using ceramic nanofiltration membranes demonstrate that these systems can be recovered and reused efficiently. [source] Synthesis and properties of novel polyimides derived from 2,2,,3,3,-benzophenonetetracarboxylic dianhydrideJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2004Xing-Zhong Fang Abstract A new synthetic route to 2,2,,3,3,-BTDA (where BTDA is benzophenonetetracarboxylic dianhydride), an isomer of 2,3,,3,,4,-BTDA and 3,3,,4,4,-BTDA, is described. Single-crystal X-ray diffraction analysis of 2,2,,3,3,-BTDA has shown that this dianhydride has a bent and noncoplanar structure. The polymerizations of 2,2,,3,3,-BTDA with 4,4,-oxydianiline (ODA) and 4,4,-bis(4-aminophenoxy)benzene (TPEQ) have been investigated with a conventional two-step process. A trend of cyclic oligomers forming in the reaction of 2,2,,3,3,-BTDA and ODA has been found and characterized with IR, NMR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and elemental analyses. Films based on 2,2,,3,3,-BTDA/TPEQ can only be obtained from corresponding polyimide (PI) solutions prepared by chemical imidization because those from their polyamic acids by thermal imidization are brittle. PIs from 2,2,,3,3,-BTDA have lower inherent viscosities and worse thermal and mechanical properties than the corresponding 2,3,,3,,4,-BTDA- and 3,3,,4,4,-BTDA-based PIs. PIs from 2,2,,3,3,-BTDA and 2,3,,3,,4,-BTDA are amorphous, whereas those from 3,3,,4,4,-BTDA have some crystallinity, according to wide-angle X-ray diffraction. Furthermore, PIs from 2,2,,3,3,-BTDA have better solubility, higher glass-transition temperatures, and higher melt viscosity than those from 2,3,,3,,4,-BTDA and 3,3,,4,4,-BTDA. Model compounds have been prepared to explain the order of the glass-transition temperatures found in the isomeric PI series. The isomer effects on the PI properties are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2130,2144, 2004 [source] An intermediate in a new synthesis approach to ,-substituted ,-hydroxyaspartameACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2003Johny Wehbe The crystal and molecular structure of 1- tert -butyl 4-ethyl (2,R,3,R,5,R,2S,3S)-3-bromomethyl-3-hydroxy-2-[(2,-hydroxy-2,,6,,6,-trimethylbicyclo[3.1.1]hept-3,-ylidene)amino]succinate, C21H34BrNO6, is presented. This compound is an intermediate in the new synthetic route to ,-substituted ,-hydroxyaspartates, which are blockers of glutamate transport. [source] Optimized Synthesis of AMPA Receptor Antagonist ZK,187638 and Neurobehavioral Activity in a Mouse Model of Neuronal Ceroid LipofuscinosisCHEMMEDCHEM, Issue 10 2006Bernd Elger Dr. Abstract Previous structure,activity relationship studies in the search for a potent, noncompetitive , -amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor antagonist led to 2,3-dimethyl-6-phenyl-12H -[1,3]dioxolo[4,5-h]imidazo[1,2-c][2,3]benzodiazepine (ZK,187638). However, the first synthesis had some drawbacks regarding reagents, processes, and overall yield, which furthermore decreased when the synthesis was scaled up. Therefore, we now report a new synthetic route for this compound which requires fewer steps and is suited for large-scale production. This compound significantly relieved the symptoms of neuromuscular deficit in mnd mice, a model of neuronal ceroid lipofuscinosis with motor neuron dysfunction. After oral administration, the concentrations of the compound in the brain and spinal cord were about threefold higher than those in the plasma. In summary, this novel AMPA antagonist is accessible through an optimized synthetic route, has good neurobehavioral activity, oral bioavailability, and favorable brain penetration. This opens new possibilities for the treatment of devastating neurological diseases that are mediated by the AMPA receptor. [source] | |||||||||||||