3983-91-3Relevant articles and documents
C(sp3)-O bond-forming reductive elimination from PdIV with diverse oxygen nucleophiles
Camasso, Nicole M.,Prez-Temprano, Mnica H.,Sanford, Melanie S.
supporting information, p. 12771 - 12775 (2015/01/09)
This article describes an investigation of C(sp3)-O bond-forming reductive elimination reactions from PdIV complexes. Phenoxide, acetate, difluoroacetate, dimethylphosphate, tosylate, and nitrate nucleophiles are shown to participate in this reaction. In all cases, C(sp3)-O bond formation occurs with high selectivity over potentially competing C(sp2)-O coupling. Additives have a profound impact on the chemoselectivity of these reductive elimination reactions. An excess of RO- was found to limit competing C(sp3)-C(sp2) bond-forming reductive elimination, while the presence of Lewis acidic cations was found to suppress competing C(sp3)-F coupling. Mechanistic investigations were conducted, and the available data are consistent with a sequence involving pre-equilibrium dissociation of the oxyanion ligand (RO-) followed by nucleophilic attack of RO- on a cationic PdIV-alkyl intermediate.
A polyoxapolyaza macrobicyclic receptor for the recognition of zwitterions
Mateus, Pedro,Delgado, Rita,Brand?o, Paula,Félix, Vítor
supporting information; body text, p. 5529 - 5532 (2012/08/08)
A polyoxapolyaza heteroditopic macrobicyclic compound (btpN 4O3) was synthesized. The acid-base behaviour of the compound as well as its binding ability for zwitterionic amino acids were studied by potentiometry at 298.2 ± 0.1 K in H2O-MeOH (50:50 v/v) and at I = 0.10 ± 0.01 M in NMe4TsO. The H nbtpN4O3n+ showed preference for amino acids containing tetrahedral anionic groups.
Backscattering Interferometry: An alternative approach for the study of hydrogen bonding interactions in organic solvents
Pesciotta, Esther N.,Bornhop, Darryl J.,Flowers, Robert A.
supporting information; experimental part, p. 2654 - 2657 (2011/06/25)
Intermolecular interactions involving hydrogen bonds are responsible for catalysis and recognition. Traditional methods used to study hydrogen-bonding interactions are generally limited to relatively large volumes and high substrate concentrations. Backscattering Interferometry (BSI) provides a microfluidic platform to study these interactions in nonaqueous media at micromolar to nanomolar concentrations in picoliter volumes by monitoring changes in the refractive index.
POSITIVE RESIST COMPOSITION AND PATTERNING PROCESS
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, (2010/04/23)
A positive resist composition comprises (A) a resin component which becomes soluble in an alkaline developer under the action of an acid and (B) an acid generator. The resin (A) is a polymer comprising recurring units containing a non-leaving hydroxyl group represented by formula (1) wherein R1 is H, methyl or trifluoromethyl, X is a single bond or methylene, m is 1 or 2, and the hydroxyl group attaches to a secondary carbon atom. The composition is improved in resolution when processed by lithography.
Constituent Analysis of the Interaction of Solvents with the Leaving Group Anions for SN1-E1 Reactions. Thermodynamic Evidence for the Nature of the Conjugate Base of p-Nitrophenylhydrazonomalononitrile
Kondo, Yasuhiko,Kusabayashi, Shigekazu,Mitsuhashi, Tsutomu
, p. 1799 - 1804 (2007/10/02)
Enthalpies of solution in dimethyl sulphoxide and in methanol for the tetraethylammonium salt of the conjugate base of p-nitrophenylhydrazonomalononitrile were measured and compared with those of tetraethylammonium chloride.The former salt is more stable in the strongly dipolar aprotic solvent dimethyl sulphoxide than in the protic solvent methanol, whereas the latter is more stable in methanol because of hydrogen bonding of the solvent with chloride ion.Single ion enthalpies of transfer were determined in acetonitrile-methanol mixtures for the hydrazono anion as well as for tosylate ion and were dissected into constituent terms; a 'more physical' and a 'specific' interaction, solvation being due to hydrogen bonding.The hydrazono anion resembles BBun4- and ClO4- in that the contribution from the latter term is negligible.On the other hand, tosylate ion is susceptible to hydrogen bonding as is halide ion.The result is consistent with the kinetic behaviour of the leaving group anions for SN1-E1 reactions.
CATALYSIS BY AMINE SALTS OF SOME AROMATIC NUCLEOPHILIC SUBSTITUTION REACTIONS
Hirst, Jack,Onyido, Ikenna
, p. 711 - 716 (2007/10/02)
The reaction of 1-chloro-2,4-dinitrobenzene with aniline in acetonitrile is catalysed by R4NY where Y is Cl, Br, I, or toluene-p-sulphonate, but not by 1,4-diazabicyclooctane (DABCO).When the nucleophile is changed to n-butylamine or morpholine, addition of tetraethylammonium chloride has only a small effect; the reactions of all three nucleophiles are not catalysed by tetraethylammonium perchlorate.The reaction of 1-fluoro-2,4-dinitrobenzene with aniline is strongly catalysed by tetraethylammonium chloride, to a lesser extent by the bromide and toluene-p-sulphonate and also by trimethylamine hydrochloride, but not by tetraethylammonium perchlorate.The reactions of morpholine with 1-fluoro-2,4-dinitrobenzene and piperidine with 2,4-dinitrophenyl phenyl ether are not catalysed by amine salts.The results are consistent with the formation and stabilisation of the intermediate formed in aromatic nucleophilic substitution reactions by the anions of the salts, when the nucleophile is aniline
