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Bond Cleavage (bond + cleavage)
Kinds of Bond Cleavage Selected AbstractsNickel-Catalyzed Regioselective Carbomagnesation of Methylenecyclopropanes through a Site-Selective Carbon,Carbon Bond Cleavage,ANGEWANDTE CHEMIE, Issue 1 2010Jun Terao Dr. Den Ring sprengen: In Gegenwart eines Nickelkatalysators addieren Vinyl- oder Aryl-Grignard-Reagentien unter selektiver C-C-Bindungsspaltung an Methylencyclopropane (siehe Schema). Die Reaktion eröffnet einen neuen Zugang zu substituierten Homoallyl- und Allyl-Grignard-Reagentien. [source] Study of Protein Splicing and Intein-Mediated Peptide Bond Cleavage under High-Cell-Density ConditionsBIOTECHNOLOGY PROGRESS, Issue 3 2003Shamik Sharma Protein splicing elements (inteins), capable of catalyzing controllable peptide bond cleavage reactions, have been used to separate recombinant proteins from affinity tags during affinity purification. Since the inteins eliminate the use of a protease in the recovery process, the intein-mediated purification system has the potential to significantly reduce recovery costs for the industrial production of recombinant proteins. Thus far, the intein system has only been examined and utilized for expression and purification of recombinant proteins at the laboratory scale for cells cultivated at low cell densities. In this study, protein splicing and in vitro cleavage of intein fusion proteins expressed in high-cell-density fed-batch fermentations of recombinant Escherichia coli were examined. Three model intein fusion constructs were used to examine the stability and splicing/cleavage activities of the fusion proteins produced under high-cell-density conditions. The data indicated that the intein fusion protein containing the wild-type intein catalyzed efficient in vivo protein splicing during high-cell-density cultivation. Also, the intein fusion proteins containing modified inteins catalyzed efficient thiol-induced in vitro cleavage reactions. The results of this study demonstrated the potential feasibility of using the intein-mediated protein purification system for industrial-scale production of recombinant proteins. [source] ChemInform Abstract: Ring Opening of Cyclic Vinylogous Acyl Triflates Using Stabilized Carbanion Nucleophiles: Claisen Condensation Linked to Carbon,Carbon Bond Cleavage.CHEMINFORM, Issue 37 2010David M. Jones Abstract Treatment of the cyclic triflates (I) and (VII) with carbanion nucleophiles provides acyclic alkynes bearing 1,3-diketone, ,-keto ester, ,-keto phosphonate, or ,-keto phosphine oxide moieties. [source] ChemInform Abstract: Copper(I)-Catalyzed Substitution Reactions of Propargylic Amines: Importance of C(sp),C(sp3) Bond Cleavage in Generation of Iminium Intermediates.CHEMINFORM, Issue 33 2010Tsuyuka Sugiishi Abstract Substitution reactions of propargylic amines using various secondary amines proceed in the presence of a copper(I) catalyst. [source] ChemInform Abstract: Nickel-Catalyzed Regioselective Carbomagnesation of Methylenecyclopropanes Through a Site-Selective Carbon,Carbon Bond Cleavage.CHEMINFORM, Issue 19 2010Jun Terao 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: One-Pot Synthesis of Symmetric and Unsymmetric 1,1-Bis-indolylmethanes via Tandem Iron-Catalyzed C,H Bond Oxidation and C,O Bond Cleavage.CHEMINFORM, Issue 13 2010Xingwei Guo 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: A Practical Photochemically Induced Method for N,N Bond Cleavage of N,N-Disubstituted Hydrazides.CHEMINFORM, Issue 4 2010Stephane Lebrun 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: Catalyst-Free Alkylation of Sulfinic Acids with Sulfonamides via sp3 C,N Bond Cleavage at Room Temperature.CHEMINFORM, Issue 45 2009Cong-Rong Liu 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] ChemInform Abstract: C,F Bond Cleavage by Intramolecular SN2 Reaction of Alkyl Fluorides with O- and N-Nucleophiles.CHEMINFORM, Issue 33 2009Laijun Zhang 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] ChemInform Abstract: Selective Aromatic Carbon,Oxygen Bond Cleavage of Trifluoromethoxyarenes: A Trifluoromethoxy Group as a Convertible Directing Group.CHEMINFORM, Issue 4 2009Akinori Iijima 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] ChemInform Abstract: Substrate-Controlled Selective Proximal and Distal C,C Bond Cleavage via Lewis Acid Mediated O-Acylation of 2-(Arylmethylene)cyclopropylaldehyde: A Stereoselective Synthesis of Bifunctional Methylenecyclobutanes and 1,3-Conjugated Dienes.CHEMINFORM, Issue 3 2009Xian Huang 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] ChemInform Abstract: Mild C,C Bond Cleavage in Cycloalkanes by the Action of New Lanthanide Catalysts LnCl3×3H2O×3(EtO)2AlOH.CHEMINFORM, Issue 52 2008R. G. Bulgakov 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] ChemInform Abstract: Lewis Acid Promoted Carbon,Carbon Bond Cleavage of ,-Silyloxy-,-hydroxy-,-diazoesters.CHEMINFORM, Issue 32 2008Cristian Draghici 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] ChemInform Abstract: Nucleophilic Substitution Accompanying Carbon,Carbon Bond Cleavage Assisted by a Nitro Group.CHEMINFORM, Issue 15 2008Yumi Nakaike 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] Novel C,C Bond Cleavage from Arylacetonitriles in Alcohols to Aryl Carboxylic Esters Using Potassium Iodide and Catalytic Amount of Samarium.CHEMINFORM, Issue 10 2007Mingxin Yu 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] N-Heterocyclic Carbene Catalyzed C,C Bond Cleavage in Redox Esterifications of Chiral Formylcyclopropanes.CHEMINFORM, Issue 52 2006Stephanie S. Sohn 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] Formation of Indene Derivatives from Bis(cyclopentadienyl)titanacyclopentadienes with Alkyl Group Migration via Carbon,Carbon Bond Cleavage.CHEMINFORM, Issue 17 2006Tamotsu Takahashi 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] Organocatalytic Ring Expansion of ,-Lactams to ,-Lactams Through a Novel N1,C4 Bond Cleavage.CHEMINFORM, Issue 1 2006Direct Synthesis of Enantiopure Succinimide Derivatives. No abstract is available for this article. [source] Ru- and Rh-Catalyzed C,C Bond Cleavage of Cyclobutenones: Reconstructive and Selective Synthesis of 2-Pyranones, Cyclopentenes, and Cyclohexenones.CHEMINFORM, Issue 6 2005Teruyuki Kondo Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Simple and Regioselective Carbon-Oxygen Bond Cleavage Using Niobium(V).CHEMINFORM, Issue 38 2004Shigeru Arai Abstract For Abstract see ChemInform Abstract in Full Text. [source] Carbon,Carbon Bond Cleavage of Diynes Through the Hydroamination with Transition Metal Catalysts.CHEMINFORM, Issue 40 2003Tomohiro Shimada No abstract is available for this article. [source] ChemInform Abstract: Oxidative Double Bond Cleavage of ,-Substituted Styrenes with Molecular Oxygen.CHEMINFORM, Issue 33 2002Yujiro Hayashi 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: Synthetic Design of Carbonyl-Group-Containing Compounds Based on C,O Bond Cleavage Promoted by Pd Complexes.CHEMINFORM, Issue 16 2002Akio Yamamoto 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: Unexpected Catalyzed C=C Bond Cleavage by Molecular Oxygen Promoted by a Thiyl Radical.CHEMINFORM, Issue 46 2001Xavier Baucherel 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: Palladium-Catalyzed Coupling Reactions of Biphenylene with Olefins, Arylboronic Acids, and Ketones Involving C,C Bond Cleavage.CHEMINFORM, Issue 41 2001Tetsuya Satoh 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] Steady-State and Time-Resolved Studies on Photoinduced Disulfide Bond Cleavage Using Aniline as an Electron DonorCHEMPHYSCHEM, Issue 3 2004Changyuan Lu Dr. Crucial radicals: The aniline-mediated photochemical disulfide bond cleavage of linear or cyclic disulfide compounds (RSSR; see scheme) is shown to initiate by a photoinduced electron transfer from the excited state of aniline as well as by reduction with solvated electrons produced by the direct photoionization of aniline. The crucial intermediates in the disulfide cleavage are the disulfide radical anions. [source] ChemInform Abstract: Palladium-Catalyzed Direct Arylations, Alkenylations, and Benzylations Through C,H Bond Cleavages with Sulfamates or Phosphates as Electrophiles.CHEMINFORM, Issue 27 2010Lutz Ackermann 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] Palladium-Catalyzed Reaction of 2-Hydroxy-2-methylpropiophenone with Aryl Bromides: A Unique Multiple Arylation via Successive C,C and C,H Bond Cleavages.CHEMINFORM, Issue 44 2004Hiroyuki Wakui No abstract is available for this article. [source] Treating [K4(H2O)0.5][SnTe4] with PPh4+ or AsPh4+: Formation of a Highly Air-Stable Tellurostannate Salt, a Tellurolate with One-Coordinate Te Atoms, and a Polytelluride Salt with ,1[Te4(H2O)2]2, Chains,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2007Eugen Ruzin Abstract In reactions of potassium orthotellurostannates with EPh4Cl (E = P, As), different single-crystalline products are obtained. An air-stable dimeric tellurostannate forms by partial replacement of strongly interacting K+ cations by weakly interacting or noninteracting [PPh4]+ ions. For E = As, an equally air-stable tellurophenolate, in which Te has the rare coordination number 1, results upon As,C bond cleavage at a tetraphenylarsonium cation. Oxidation of the air-sensitive [Sn2Te6]4, anion and Te2, by O2 (air) affords a tetratelluride salt with strands of H2O-bridged [Te4]2, anions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Functional characterization of an orphan cupin protein from Burkholderia xenovorans reveals a mononuclear nonheme Fe2+ -dependent oxygenase that cleaves ,-diketonesFEBS JOURNAL, Issue 20 2009Stefan Leitgeb Cupins constitute a large and widespread superfamily of ,-barrel proteins in which a mononuclear metal site is both a conserved feature of the structure and a source of functional diversity. Metal-binding residues are contributed from two core motifs that provide the signature for the superfamily. On the basis of conservation of this two-motif structure, we have identified an ORF in the genome of Burkholderia xenovorans that encodes a novel cupin protein (Bxe_A2876) of unknown function. Recombinant Bxe_A2876, as isolated from Escherichia coli cell extract, was a homotetramer in solution, and showed mixed fractional occupancy of its 16.1 kDa subunit with metal ligands (0.06 copper; 0.11 iron; 0.17 zinc). Our quest for possible catalytic functions of Bxe_A2876 focused on Cu2+ and Fe2+ oxygenase activities known from related cupin enzymes. Fe2+ elicited enzymatic catalysis of O2 -dependent conversion of various ,-diketone substrates via a nucleophilic mechanism of carbon,carbon bond cleavage. Data from X-ray absorption spectroscopy (XAS) support a five-coordinate or six-coordinate Fe2+ center where the metal is bound by three imidazole nitrogen atoms at 1.98 Å. Results of structure modeling studies suggest that His60, His62 and His102 are the coordinating residues. In the ,best-fit' model, one or two oxygens from water and a carboxylate oxygen (presumably from Glu96) are further ligands of Fe2+ at estimated distances of 2.04 Å and 2.08 Å, respectively. The three-histidine Fe2+ site of Bxe_A2876 is compared to the mononuclear nonheme Fe2+ centers of the structurally related cysteine dioxygenase and acireductone dioxygenase, which also use a facial triad of histidines for binding of their metal cofactor but promote entirely different substrate transformations. [source] | |||||||||||||||||||||||||||||||||||||