Damage of polyesters by the atmospheric free radical oxidant NO₃^•: a product study involving model systems

• Catrin Goeschen and
• Uta Wille

Beilstein J. Org. Chem. 2013, 9, 1907–1916, doi:10.3762/bjoc.9.225

• the reaction outcome and mechanic considerations, were avoided. It should also be noted that NO2• is in equilibrium with its dimer dinitrogen tetroxide, N2O4. In solution the NO2•/N2O4 equilibrium constant favours the dimer [15], and N2O4 can be oxidized with O3 to give N2O5. Gas-phase kinetic studies

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• (A11a) [106]. There are indirect evidences that agostic bonds, solvent and weakly coordinating counteranions could easily exchange their role of stabilizing the unsaturated complex by placement at the vacant site. Although no kinetic studies on exchanges of these kinds of ligands have been reported, the

Kinetics and mechanism of the anilinolysis of aryl phenyl isothiocyanophosphates in acetonitrile

• Hasi Rani Barai and
• Hai Whang Lee

Beilstein J. Org. Chem. 2013, 9, 615–620, doi:10.3762/bjoc.9.68

• Hasi Rani Barai Hai Whang Lee Department of Chemistry, Inha University, Incheon 402-751, Korea 10.3762/bjoc.9.68 Abstract Kinetic studies on the reactions of Y-aryl phenyl isothiocyanophosphates with substituted X-anilines and deuterated X-anilines were carried out in acetonitrile at 55.0 °C. The

• transition state (TS). To extend the kinetic studies on the phosphoryl transfer reactions, the reactions of Y-aryl phenyl isothiocyanophosphates (1a–e) with substituted anilines (XC6H4NH2) and deuterated anilines (XC6H4ND2) have been investigated kinetically in acetonitrile (MeCN) at 55.0 ± 0.1 °C (Scheme 1

Electron and hydrogen self-exchange of free radicals of sterically hindered tertiary aliphatic amines investigated by photo-CIDNP

• Martin Goez,
• Isabell Frisch and
• Ingo Sartorius

Beilstein J. Org. Chem. 2013, 9, 437–446, doi:10.3762/bjoc.9.46

• representatives that yield CIDNP from the radical-ion pairs and from the pairs of neutral radicals, respectively. Owing to competing side-reactions, kinetic studies were not feasible with triethylamine, but for the two amines of this work, they are. As we will show, depending on the sensitizer, different spin

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• (distinguishable as rotamers with respect to the P–OAr bond) while in the other, three distinct guest components with site-occupancies 0.44, 0.29 and 0.27 appear, the last having a reversed orientation relative to all the other components. Kinetic studies of the alkaline hydrolysis of fenitrothion in the presence

• ) and heptakis(2,3,6-tri-O-methyl)-β-CD (TRIMEB) and the guest [5]. We have also described the results of solution-based kinetic studies aimed at determining the effect of the presence of various CDs on the rate of alkaline hydrolysis of fenitrothion in aqueous solution containing 2% dioxane at 25 °C [6

• not the case under our reaction conditions; therefore we think that the type A complex is predominant for β-CD and DIMEB. Kinetic studies The hydrolysis reaction of fenitrothion takes place with P–O bond fission as shown in Scheme 1 [12] and it was studied in the presence of constant HO− and variable

An improved synthesis of a fluorophosphonate–polyethylene glycol–biotin probe and its use against competitive substrates

• Hao Xu,
• Hairat Sabit,
• Gordon L. Amidon and
• H. D. Hollis Showalter

Beilstein J. Org. Chem. 2013, 9, 89–96, doi:10.3762/bjoc.9.12

• [6]. Thus it is important to perform kinetic studies on a specific tissue or cell line before the start of competition experiments. Toward this end, Caco-2 samples were prepared and incubated with FP–PEG–biotin 1 over different time courses ranging from 1 to 30 min (Figure 3). The sample from each

New efficient ligand for sub-mol % copper-catalyzed C–N cross-coupling reactions running under air

• Per-Fredrik Larsson,
• Peter Astvik and
• Per-Ola Norrby

Beilstein J. Org. Chem. 2012, 8, 1909–1915, doi:10.3762/bjoc.8.221

• could be involved in the mass transfer of the heterogeneous base. Conclusion In summary, a new and efficient ligand (DMDETA) for sub-mol % copper-catalyzed C–N cross coupling has been synthesized and evaluated in kinetic studies. DMDETA, together with DMEDA, is one of the few reported ligands that work

Self-assembled organic–inorganic magnetic hybrid adsorbent ferrite based on cyclodextrin nanoparticles

• Ângelo M. L. Denadai,
• Frederico B. De Sousa,
• Joel J. Passos,
• Fernando C. Guatimosim,
• Kirla D. Barbosa,
• Ana E. Burgos,
• Fernando Castro de Oliveira,
• Jeann C. da Silva,
• Bernardo R. A. Neves,
• Nelcy D. S. Mohallem and
• Rubén D. Sinisterra

Beilstein J. Org. Chem. 2012, 8, 1867–1876, doi:10.3762/bjoc.8.215

• microscopy (AFM). Size distribution and colloidal suspension stability were characterized by dynamic light scattering (DLS) and sedimentation kinetic studies by using UV–vis spectroscopy. Ferrite binding sites were characterized by zeta potential (ZP) and potentiometric titration. The free volume for both

Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes

• Gianluigi Broggini,
• Egle M. Beccalli,
• Andrea Fasana and
• Silvia Gazzola

Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198

• moderate to good yield (Scheme 6). A mechanism including an electrophilic palladation involving the pyridinyl chelation was thought to be plausible taking into account the outcome of the reaction performed on isotopically labeled substrates as well as by kinetic studies of variously substituted indoles

A quantitative approach to nucleophilic organocatalysis

• Herbert Mayr,
• Sami Lakhdar,
• Biplab Maji and
• Armin R. Ofial

Beilstein J. Org. Chem. 2012, 8, 1458–1478, doi:10.3762/bjoc.8.166

• chromatography on silica gel. The presence of triethylamine (5%) in the eluent (ethyl acetate/n-pentane) turned out to be crucial to avoid decomposition of these enamines on the column [82][83]. Kinetic studies of their reactions with benzhydrylium ions 18 of suitable electrophilicity showed that introduction of

• ], we synthesized and isolated the O-methylated Breslow intermediates 55a–c, 57, and 59 as described in Figure 27 [114]. Some of them were characterized by single-crystal X-ray crystallography. Kinetic studies of their reactions with benzhydrylium ions provided their reactivity parameters N and sN [114

Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica

• Lu Zou,
• Ruixiang Blake Zheng and
• Todd L. Lowary

Beilstein J. Org. Chem. 2012, 8, 1219–1226, doi:10.3762/bjoc.8.136

• )(OBn)2, NIS, AgOTf, CH2Cl2, 67%; (e) (i) H2, Pd(OH)2–C, toluene, Et3N, pyridine; (ii) CH3OH–H2O–Et3N, 5:2:1, 72%. KM, kcat, and kcat/KM of GDP-ManPP kinetic studies. Supporting Information Supporting Information File 372: Detailed experimental procedures. Acknowledgements This work was supported by

Recent advances towards azobenzene-based light-driven real-time information-transmitting materials

• Jaume García-Amorós and
• Dolores Velasco

Beilstein J. Org. Chem. 2012, 8, 1003–1017, doi:10.3762/bjoc.8.113

• substitution (type-I), that is, bearing a push–pull configuration. Secondly, kinetic studies of different azophenolic systems (type-II) will be presented, since these azoderivatives exhibit a fast thermal back reaction due to their capability to establish an azo-hydrazone tautomeric equilibrium. Both type-I

New library of aminosulfonyl-tagged Hoveyda–Grubbs type complexes: Synthesis, kinetic studies and activity in olefin metathesis transformations

• Etienne Borré,
• Frederic Caijo,
• Christophe Crévisy and
• Marc Mauduit

Beilstein J. Org. Chem. 2010, 6, 1159–1166, doi:10.3762/bjoc.6.132

• Chimie de Rennes, Av. du Général Leclerc, CS 50837 35708 Rennes cedex 7, France 10.3762/bjoc.6.132 Abstract Seven novel Hoveyda–Grubbs precatalysts bearing an aminosulfonyl function are reported. Kinetic studies indicate an activity enhancement compared to Hoveyda’s precatalyst. A selection of these

• catalysts was investigated with various substrates in ring-closing metathesis of dienes or enynes and cross metathesis. The results demonstrate that these catalysts show a good tolerance to various chemical functions. Keywords: cross-metathesis; kinetic studies; olefin metathesis; RCM; ruthenium

• between the SIPr unit and the electronic activation of the benzylidene fragment. Conclusion A new library of Hoveyda type catalysts bearing aminosulfonyl functions has been synthesized. Their activity profiles have been investigated through kinetic studies and through evaluation of a group of substrates

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

• Michael North and
• Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

• achieved at atmospheric pressure and room temperature [74][75][76][77], or in a gas-phase continuous flow reactor [78], thus facilitating the use of waste carbon dioxide in this process [79]. In this paper we give full details of the use of catalyst 2 in propylene carbonate, and describe kinetic studies

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• molecular weight distributions. The best reaction conditions, optimized by kinetic studies, were bulk polymerization at 110 °C. Using P2VP as a macroinitiator, the synthesis of new soluble linear block copolymers of P2VP and poly(N-isopropylacrylamide) (PNIPAAm) (P2VP-block-PNIPAAm) was possible. The

Kinetic studies and predictions on the hydrolysis and aminolysis of esters of 2-S-phosphorylacetates

• Milena Trmčić and
• David R. W. Hodgson

Beilstein J. Org. Chem. 2010, 6, 732–741, doi:10.3762/bjoc.6.87

• 2 in such a way as to favour aminolysis over undesired hydrolysis processes. In addition to kinetic studies, we present predictions of leaving group characteristics, based on correlation with literature data, that should allow for improvement in the performance of 2-bromoacetic acid esters 1 as

• /MeCN solvent system was employed where the reagents formed homogeneous solutions that we hoped to use for simple kinetic studies. When using the N-hydroxybenzotriazole system (leaving group pKaH = 4.60 [5]), we performed several experiments at different pH values and at concentrations of ~0.02 M for

• , we did not pursue the use of this system any further. In order to gain an understanding of the aminolysis vs hydrolysis processes, we re-focused our studies towards activated bromoacetic acid phenyl ester systems that were more readily amenable to kinetic studies via UV–vis spectrophotometry. The 2

Synthesis, characterization and photoinduced curing of polysulfones with (meth)acrylate functionalities

• Cemil Dizman,
• Sahin Ates,
• Lokman Torun and
• Yusuf Yagci

Beilstein J. Org. Chem. 2010, 6, No. 56, doi:10.3762/bjoc.6.56

• is due to the additional acrylate and methacrylate moieties incorporated. Kinetic studies concerning photopolymerization of the macromonomers were performed by photo-DSC. The results are shown in Figure 3 and Figure 4. The rate of photopolymerization vs. time plots for both PSU-DA-2000 and PSU-DM

Thematic series on supramolecular chemistry

• Christoph A. Schalley

Beilstein J. Org. Chem. 2009, 5, No. 76, doi:10.3762/bjoc.5.76

• recognition.” [1] As the above citation from a paper by Julius Rebek and his coworkers indicates, supramolecular chemistry at its beginning gave new impetus to physical organic chemistry, which at that time had got trapped in ever more detailed kinetic studies. Early on, the nature of non-covalent

The Elbs and Boyland- Sims peroxydisulfate oxidations

• E. J. Behrman

Beilstein J. Org. Chem. 2006, 2, No. 22, doi:10.1186/1860-5397-2-22

• obvious choice that was supported by a number of kinetic studies. [1] This was questioned by Edward and Whiting [2] who claimed that the molecule formed by sulfonating N,N-dimethylaniline-N-oxide(1) did not rearrange to the o-sulfate(2) but rather decomposed by hydrolysis. However, repetition of this work