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Building Blocks (building + block)
Kinds of Building Blocks Selected AbstractsA PCP-Pincer RuII,Terpyridine Building Block as a Potential "Antenna Unit" for Intramolecular SensitizationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2007Marcella Gagliardo Abstract The redox- and photoactive mononuclear complex [Ru(PCP)(tpy,DTTANa4)]Cl {PCP = [C6H3(CH2PPh2)2 -2,6],; tpy,DTTA4, = 4,-(2,2,:6,,2,-terpyridine)-diethylenetriamine- N,N,N,,N, -tetraacetate} possesses an externally directed, vacant N3O4 polyaminocarboxylate-type binding site that coordinates to lanthanide(III) ions to give the neutral heterodinuclear RuII,LnIII complexes [Ru(PCP)(tpy,DTTA)Ln(H2O)2] (Ln = Gd3+, Eu3+). The photophysical properties of solutions of the mononuclear complex [Ru(PCP)(tpy,DTTANa4)]Cl were investigated in MeOH/EtOH (1:4) and compared to those of the solutions of heterodinuclear complexes [Ru(PCP)(tpy,DTTA)Ln(H2O)2] (Ln = Gd3+, Eu3+). Rigid matrix excitation at 77 K of the ,,* level of the ruthenium chromophore in the [Ru(PCP)(tpy,DTTA)Eu(H2O)2] complex results in a weak europium(III) emission pointing to a transfer of energy from Ru,Eu as a result of the metal-to-ligand charge-transfer (MLCT) excited state of the ruthenium component to the luminescent lanthanide ion. The excited state lifetime of the europium complex is 0.2 ms in methanol solution. In deuterated solvents, the lifetime increases to 0.4 ms, which indicates that the process is solvent-dependent as a result of the strongly coordinated molecules of water that are responsible for the quenching in nondeuterated solvents.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Supramolecular Chemistry Based on [W3S4(H2O)6Cl3]+ , A Versatile Building BlockEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2004Maxim N. Sokolov Abstract The cluster [W3S4(H2O)6Cl3]+ (which is present in solutions of [W3S4(H2O)9]4+ in 1,4 M HCl) reacts with the macrocyclic cavitand cucurbituril (C36H36N24O12) to form supramolecular adducts of 2:1 cluster/cucurbituril stoichiometry, where two portals of cucurbituril (which contains a water molecule in its cavity) are closed by two cluster cations. These aggregates are bound together in the solid by complementary hydrogen bonds between coordinated Cl, and the cations H9O4+ to give chains. Thus, a supramolecular architecture is achieved from three different but complementary building blocks. The packing of the chains affords a honeycomb structure (hexagonal symmetry) with channels (about 5.2 Å in diameter). The overall stoichiometry is (H9O4){[W3S4(H2O)6Cl3]2(C36H36N24O12)}Cl3·16.15H2O (1). [W3S4(H2O)6Cl3]+ reacts with SbCl3 in 6 M HCl to give cuboidal [W3(SbCl3)S4(H2O)6Cl3]+, which forms with the macrocyclic cavitand cucurbituril a 2:1 cluster/cucurbituril adduct , a discrete supramolecule consisting of five independent molecular units. In the solid it crystallizes as a salt of very rare anion [SbCl6]3, with the stoichiometry {[W3(SbCl3)S4(H2O)6Cl3]2(C36H36N24O12)}(SbCl6)2/3·12H2O (2). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Alkoxy-5-nitrosopyrimidines: Useful Building Block for the Generation of Biologically Active CompoundsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2010Antonio Marchal Abstract Several alkoxy-5-nitrosopyrimidines were synthesised and high regioselective and sequential nucleophilic aromatic substitution of methoxy groups in 2-amino-4,6-dimethoxy-5-nitrosopyrimidine was observed. The approach was applied to the synthesis of valuable polyfunctionalised aminopyrimidines capable of mimicking fused heterobicyclic derivatives of biological interest. In addition, new compounds were evaluated as antivirals and their usefulness as synthetic intermediates was demonstrated. [source] Synthesis of an Enantiomerically Pure Building Block for the Synthesis of Hydroporphyrins,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2007Genevieve Etornam Adukpo Abstract The enantiomerically pure pyrrolidine diester 4 is a useful building block for the synthesis of chiral hydroporphyrin compounds. Treatment of optically active aromatic amines with bislactone 5 gave pairs of N -alkylated lactam-lactone diastereomers 6 and 8. These diastereomers were separated by MPL chromatography and in the case of 8 they could be debenzylated to yield the enantiomerically pure lactam-lactone 7 and its enantiomer. The (,)-lactam-lactone enantiomer 7 was further transformed into building block 4.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] ChemInform Abstract: Alternative Route to the Diisocyanate Building Block 1,4-Diisocyanato-4-methylpentane (DIMP).CHEMINFORM, Issue 43 2010Matthew C. Davis Abstract Diisocyanate (VIII) is regioselectively synthesized starting from isobutyronitrile in six steps using a double Curtius rearrangement as the key reaction. [source] ChemInform Abstract: A New Route for the Synthesis of (R)-Glyceraldehyde Acetonide: A Key Chiral Building Block.CHEMINFORM, Issue 24 2010K. Chandra Babu 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: Thiomaleic Anhydride: A Convenient Building Block for the Synthesis of ,-Substituted ,- and ,-Lactones Through Free-Radical Addition, Nucleophilic Ring Opening, and Subsequent Thiocarboxylate Manipulation.CHEMINFORM, Issue 4 2010David Crich 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: Cyanamide: A Convenient Building Block to Synthesize 4-Aryl-2-cyanoimino-3,4-dihydro-1H-pyrimidine Systems via a Multicomponent Reaction.CHEMINFORM, Issue 40 2008R. Hulme Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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] Isocorannulenofuran: A Versatile Building Block for the Synthesis of Large Buckybowls.CHEMINFORM, Issue 15 2007Andrzej Sygula Abstract ChemInform 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. [source] Usymmetrical Polyheteropolyene: A Versatile Building Block for the Preparation of Pyrrolo[2,1-b]thiazoles and 2H-Thiopyrano[2,3-b]pyridines.CHEMINFORM, Issue 1 2007Cyrille Landreau Abstract ChemInform 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. [source] Sphingolipid Synthesis via Olefin Cross Metathesis: Preparation of a Differentially Protected Building Block and Application to the Synthesis of D-erythro-Ceramide.CHEMINFORM, Issue 50 2004Anand Narain Rai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Facile Synthesis of 4-Substituted-4-aminopiperidine Derivatives, the Key Building Block of Piperazine-Based CCR5 Antagonists.CHEMINFORM, Issue 46 2004Xiao-Hua Jiang Abstract For Abstract see ChemInform Abstract in Full Text. [source] 2-Aminothiabutadiene as Useful Building Block in the Synthesis of 2-Aminothiopyrans and 2-Aminothiophenes.CHEMINFORM, Issue 45 2004Aelig Robin Abstract For Abstract see ChemInform Abstract in Full Text. [source] Stereoselective Synthesis of Alkynyl C-2-Deoxy-,-D-ribofuranosides via Intramolecular Nicholas Reaction: A Versatile Building Block for Nonnatural C-Nucleosides.CHEMINFORM, Issue 29 2003Masayoshi Takase Abstract For Abstract see ChemInform Abstract in Full Text. [source] 5,6-Bis(trimethylsilyl)benzo[c]furan: An Isolable Versatile Building Block for Linear Polycyclic Aromatic Compounds.CHEMINFORM, Issue 2 2003Siu-Hin Chan No abstract is available for this article. [source] dl-BiTOT , A Novel Building Block for Electroactive Oligomers and Polymers in Semiconductor Applications.CHEMINFORM, Issue 39 2002Fredrik von Kieseritzky No abstract is available for this article. [source] ChemInform Abstract: Facile Enantioselective Synthesis of a Key Homoallylic Alcohol Building Block for Polyketide Synthesis: TiF4,BINOL Catalyzed Allylsilylation with Allyl Trimethylsilane.CHEMINFORM, Issue 16 2002Jeffrey W. Bode 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: ,-(Trifluoromethyl)ethenyl Boronic Acid (II) as a Useful Trifluoromethyl Containing Building Block.CHEMINFORM, Issue 35 2001Palladium-Catalyzed Coupling with Aryl Halides., Preparation 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: (S)-Thiirancarboxylic Acid as a Reactive Building Block for a New Class of Cysteine Protease Inhibitors.CHEMINFORM, Issue 14 2001Tanja Schirmeister 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] Chelating Dialkoxide Titanium Complex: A Versatile Building Block for the Construction of Heterometallic DerivativesCHEMISTRY - A EUROPEAN JOURNAL, Issue 10 2007Rosa Fandos Dr. Abstract The heterometallic complex [TiCp*(O2Bz)2AlMe2] (2) has been synthesised by reaction of [TiCp*(O2Bz)(OBzOH)] (1) with AlMe3 (Cp*=,5 -C5Me5; Bz=benzyl). Complex 1 reacts with HOTf to yield the cationic derivative [TiCp*(OBzOH)2]OTf (3) (HOTf=HSO3CF3). Compound 3 reacts with [{M(,-OH)(cod)}2] (M=Rh, Ir; cod=cyclooctadiene) to render the early,late heterometallic complexes [TiCp*(O2Bz)2{M(cod)}2]OTf (M=Rh (4); Ir (5)). The molecular structure of complex 4 has been established by single-crystal X-ray diffraction studies. [source] Rational Design of Solid Catalysts for the Selective Use of Glycerol as a Natural Organic Building BlockCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 7 2008François Jérôme Dr. Abstract Glycerol is the main co-product of the vegetable oils industry (especially biodiesel). With the rapid development of oleochemistry, the production of glycerol is rapidly increasing and chemists are trying to find new applications of glycerol to encourage a better industrial development of vegetable oils. In this Review, attention is focused on the selective use of glycerol as a safe organic building block for organic chemistry. An overview is given of the different heterogeneous catalytic routes developed by chemists for the successful and environmentally friendly use of glycerol in sustainable organic chemistry. In particular, the effects of different catalyst structural parameters are discussed to clearly highlight how catalysis can help organic chemists to overcome the drawbacks stemming from the use of glycerol as a safe organic building block. It is shown that heterogeneous catalysis offers efficient routes for bypassing the traditional use of highly toxic and expensive epichlorohydrin, 3-chloro-1,2-propanediol, or glycidol, which are usually used as a glyceryl donor in organic chemistry. [source] Synthesis, Photophysics and Morphology of a Conjugated Polymer with Azobenzene Building Block in the BackboneCHINESE JOURNAL OF CHEMISTRY, Issue 7 2010Dezhi Shen Abstract A conjugate polymer poly[p -(phenyleneethylene)-alt-(phenyleneazophenyleneethylene)] (PPEPAPE) containing azobenzene building block in the polymer backbone was synthesized via Sonogashira cross-coupling of 4,4,-diiodoazobenzene and 1,4-diethynyl-2,5-didodecyloxybenzene. All the monomers and the resulting polymer were well characterized. The polymer had a relatively high molecular weight and showed very good solubility (,10 mg/mL) in common organic solvents. The photophysics of this polymer in solution and in film was investigated. The surface morphology of the films was studied by scanning electron microscope (SEM) and the relationship between the morphology and absorbance was discussed. This polymer has good film-forming property, broad absorbance and no emission, which might make it a good candidate for the photovoltaic material in the solar cell. [source] Comparative Study of Cyanobacteria as Biocatalysts for the Asymmetric Synthesis of Chiral Building BlocksENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2006J. Havel Abstract The three representative cyanobacteria, Synechococcus PCC7942, Anabaena variabilis, and Nostoc muscorum, were studied for their ability to asymmetrically reduce the prochiral ketones 2,-3,-4,-5,-6,-pentafluoroacetophenone, ethyl 4-chloroacetate, 4-chloroacetophenone, and ethylbenzoylacetate to the corresponding chiral alcohols. Photosynthesis as well as respiration was applied for intracellular regeneration of the NAD(P)H cofactor. It was shown for the first time that all cyanobacteria were able to reduce the prochiral ketones asymmetrically without light for cofactor regeneration. By comparison of the cell specific product formation capacities of cyanobacteria with typical heterotrophic whole cell biocatalysts in batch processes, it is shown that comparable or, in some cases, better performances at high enantiomeric excess (ee > 99.8,%) are obtained. As a consequence of a generally strong product inhibition, in situ product removal must be applied in order to restore process efficiency when using cyanobacteria as biocatalysts. [source] Rarely Decorated Rutile Frameworks Built from Triangular Organic Spacers and Distorted Octahedral Co3 Building BlocksEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 24 2007Feng Luo Abstract Under mild temperatures, the self-assembly of CoCl2 and H3BTC in a solution of dmso generates a guest-free metal,organic polymer, namely Co3(BTC)2(,1 -dmso)2(,2 -dmso)2(1: dmso = dimethylsulfoxide, H3BTC = 1,3,5-benzenetricarboxylic acid). In 1, the CoII ions show the six-coordinate octahedral geometry completed by the BTC3, ions and the dmso oxygen atoms; remarkably, the coordinated dmso ligands not only act as terminal ligands to complete the octahedral geometry of the CoII ions, but also play an important role in bridging CoII ions together to give the Co3 secondary building units (SBUs). From a topological viewpoint, this novel polymer is classified to be the decorated (3,6)-connected rutile net with the (4.62)2(42.610.83) topology, where BTC3, ligands and Co3 SBUs are viewed to be the 3- and 6-connected nodes, respectively. In addition, the magnetic properties of 1 are explored by using a linear trinuclear cobalt mode, thusleading to g = 2.41, J = ,34.92 cm,1, TIP = 340,×,10,6 cm3,mol,1,, = ,6 K (a , parameter was included to take into account intertrinuclear interactions).(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] 1-Alkoxyamino-2-nitroalkanes as Key Building Blocks for a Chemo- and Diastereoselective Synthesis of a New Type of Polyfunctionalized N -AlkoxypiperidineEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 28 2010M. Ángeles López-García Abstract A highly efficient conversion of ,-nitrostyrenes into a new kind of functionalized N -alkoxy-2-hydroxypiperidine in two steps was developed, giving excellent yields and diastereoselectivity. The prepared compounds are the first examples of N -alkoxy-2-hydroxypiperidines. The synthetic approach involved the conjugate addition of alkoxyamines to ,-nitrostyrenes, followed by Michael addition of the isolated nitroalkoxyamines to ,,,-unsaturated carbonyl compounds, and intramolecular addition of the alkoxyamino group to the carbonyl functionality of the (non-isolated) adducts. Although three stereogenic centers are formed, only one diastereoisomer was detected. This unprecedented sequence of reactions can also be performed in a one-pot fashion. [source] Silylene/Oxazolidinone Double-Locked Sialic Acid Building Blocks for Efficient Sialylation Reactions in DichloromethaneEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 25 2009Shinya Hanashima Abstract We describe efficient sialylation reactions in CH2Cl2 with the use of silylene/oxazolidinone double-locked sialic acid building blocks. The building blocks were synthesized from 4,5-oxazolidinone-protected phenylthiosialoside. In sialylation reactions towards primary and relatively reactive secondary hydroxy groups on the galactosides, the double-locked building blocks provided desired coupling products in good yields with excellent ,-selectivities. In the sialylation reaction with the C3-OH of the galactoside, the double-locked building blocks expressed significantly better ,-selectivity in comparison with the results obtained by using the oxazolidinone-locked building block. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Short and Efficient Synthesis of Alkyne-Modified Amino Glycoside Building BlocksEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2009Claudine M. Klemm Abstract In the light of recent progress in RNA biology, the need for molecules that bind to RNA and thus may be suited to manipulating RNA-mediated processes is steadily increasing. We present a very short and efficient synthetic route to alkyne-modified neamine and 2-deoxystreptamine derivatives on a half-gram scale. These derivatives are suitable for constructing a library of potential divalent RNA binders by copper-catalysed 1,3-dipolar cycloaddition to diazides ("click chemistry"). The conjugate dimers thus formed inhibitedDicer-mediated micro-RNA maturation with IC50 values between 0.6 and 15 ,M.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis of Enantiomerically Pure Highly Functionalized Furanoid Glycal and 2,5-Dihydrofuran Building Blocks,,§EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2009Pinki Pal Abstract Differently protected enantiomerically pure furanoid glycals (5a,d) and highly functionalized 2,5-dihydrofurans (6a,b) were synthesized from their respective 2,3,4-trisubstituted tetrahydrofurans. These furanoid glycals were identified as1,4-anhydro-2-deoxy-5,6- O -isopropylidene-3- O -benzyl- L -arabino-hex-1-enitol, 1,4-anhydro-2-deoxy-5,6- O -isopropylidene-3- O -benzyl- L -ribo-hex-1-enitol, 1,4-anhydro-2-deoxy-5,6- O -isopropylidene-3- O -benzyl- D -ribo-hex-1-enitol and 1,4-anhydro-2-deoxy-5,6- O -isopropylidene-3- O -benzyl- D -arabino-hex-1-enitol, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Novel Building Blocks: 1-Aryl-2-chloro-1-ethoxyethenes , Preparations and Transformations,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2007Mitsuhiro Yoshimatsu Abstract We described here a simple method for the preparation of 1-aryl-2-chloro-1-ethoxyethenes 2a,u, which are prodrugs for Alzheimer's disease, by the reaction of dichloroacetaldehyde diethyl acetal with various aryl and alkenyllithium compounds in high yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Tetrahydropyran-Amino Acids: Novel Building Blocks for Gramicidin-Hybrid Ion ChannelsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2006Sabine Schröder Abstract The stereoselective synthesis of a cis -2,6-disubstituted tetrahydropyran bearing a ,-amino acid has been achieved starting from N -Boc-leucinal. The THP amino acid was incorporated into peptide sequences and the structural consequences were studied by X-ray crystallography and NMR analysis. Single-channel current measurements showed that the THP amino acid is a suitable substitute for positions 11 and 12 of the gramicidin ion channel. The resulting hybrid ion channel revealed Eisenman I ion selectivity and an ion-dependence of the channel dwell time. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] | |||||||||||||||||||||||||||||||||||||||||||