7500-05-2Relevant academic research and scientific papers
Simple acyclic molecules containing a single charge-assisted O-H group can recognize anions in acetonitrile?:?water mixtures
Goodwin, Rosemary J.,Blyth, Mitchell T.,Fung, Alfred K. K.,Smith, Leesa M.,Norcott, Philip L.,Tanovic, Sara,Coote, Michelle L.,White, Nicholas G.
, p. 2794 - 2803 (2021)
Hydroxypyridinium and hydroxyquinolinium compounds containing acidic O-H groups attached to a cationic aromatic scaffold were synthesized,i.e. N-methyl-3-hydroxypyridinium (1+) andN-methyl-8-hydroxyquinolinium (2+). These very simple
Preparation of a series of N-alkyl-3-boronopyridinium halides and study of their stability in the presence of hydrogen peroxide
Karpichev, Yevgen,Matondo, Hubert,Kapitanov, Illia,Savsunenko, Oleksandr,Vedrenne, Marc,Poinsot, Verena,Rico-Lattes, Isabelle,Lattes, Armand
, p. 1059 - 1065 (2012)
A simple and efficient protocol for the preparation of a series of N-alkyl-3-boronopyridinium salts is described which requires exposure of 3-pyridineboronic acid neopentylglycol ester and corresponding alkyle halide to microwave irradiation followed by b
Synthesis and evaluation of the performance of a small molecule library based on diverse tropane-related scaffolds
Lowe, Robert A.,Taylor, Dale,Chibale, Kelly,Nelson, Adam,Marsden, Stephen P.
supporting information, (2020/03/25)
A unified synthetic approach was developed that enabled the synthesis of diverse tropane-related scaffolds. The key intermediates that were exploited were cycloadducts formed by reaction between 3-hydroxy-pyridinium salts and vinyl sulfones or sulfonamides. The diverse tropane-related scaffolds were formed by addition of substituents to, cyclisation reactions of, and fusion of additional ring(s) to the key bicyclic intermediates. A set of 53 screening compounds was designed, synthesised and evaluated in order to determine the biological relevance of the scaffolds accessible using the synthetic approach. Two inhibitors of Hedgehog signalling, and four compounds with weak activity against the parasite P. falciparum, were discovered. Three of the active compounds may be considered to be indotropane or pyrrotropane pseudo natural products in which a tropane is fused with a fragment from another natural product class. It was concluded that the unified synthetic approach had yielded diverse scaffolds suitable for the design of performance-diverse screening libraries.
Structural considerations for charge-enhanced Br?nsted acid catalysts
Payne, Curtis,Kass, Steven R.
, (2020/03/23)
All three N-methylated and N-protonated hydroxypyridinium BArF4– salt isomers were synthesized and their hydrogen bond donating abilities were investigated. DFT and G4 theory computations along with IR spectroscopic measurements were found to be effective methods for predicting the catalytic activities of these O–H and N–H Br?nsted acids. A UV-vis titration approach for rapidly quantifying hydrogen bond donating ability revealed that carbon-hydrogen bonds also can participate in electrostatic interactions, but the presence of multiple equilibrium complexes results in a limitation of this method. In the methylated series of hydroxypyridines, the ortho and para isomers displayed modest rate enhancements relative to the meta derivative. Protonation introduces a new acidic site and the ortho hydroxypyridinium ion salt is a significantly more active catalyst than all of the other species examined. This is indicative of bidentate activation by the N–H and O–H acidic sites, and suggests a new design strategy for improving charge-enhanced catalysts.
Solvatochromism in Pure Solvents: Effects of the Molecular Structure of the Probe
Novaki, Luzia P.,El Seoud, Omar A.
, p. 648 - 655 (2007/10/03)
The following solvatochromic probes were synthesized: l-methyl-8-oxyquinolinium betaine (QB), sodium i-methyl-8-oxycuinolinium betaine-5-sulphonate (QBS), and l-rnelhyl-3-oxypyridinium betaine (PB). Their solvatochromic behavior in 28 protic and aprotic solvents was investigated, and the data compared to those of 2,6-diphenyl-4-(2,4,6-triphenyI-l-pyridmio)-l-phenolate, (RB). Solvent polarity scales based on QB, QBS, and PB correlate linearly with the ET(30) scale of RB. The Taft-Kamlet-Abboud equation satisfactorily applies to the solvatochromic data of RB, QB, QBS and PB. The multipararneter regression coefficients (a) and (s) of the above mentioned equation show that the sensitivity of the probe to solvent dipolarity/polarizability, arid hydrogen bond donation is clearly dependent on its molecular structure. This dependence was tested for a total of 26 probes of widely different structures. It is shown that this is a generai behavior, i.e., log a and s ' are linearly dependent on the p/C, and the dipole moment of the probe, respectively. VCH Verlagsgesellschaft mbH, 1996.
Structure of the Calystegines: New alkaloids of the nortropane family
Ducrot,Lallemand
, p. 3879 - 3882 (2007/10/02)
Three new alkaloids have been isolated from Calystegia sepium; their structures have been established from their 1H and 13C N.M.R. spectra, and confirmed by the synthesis of model compounds.
Proximate Charge Effects. 4. Heats of Reaction and Enthalpies of Solvent Transfer of Reactants and Products in the Deprotonation of 2-Hydroxy-N,N,N-trimethylanilinium Ion and 3-Hydroxy-N-methylpyridinium Ion
Haberfield, Paul
, p. 1423 - 1426 (2007/10/02)
Heats of neutralization, +ROH + OH- -> +RO- + H2O in water, in aqueous ethanol, and in aqueous dimethyl sulfoxide, were measured for two rigid choline analogues, namely, +ROH = 2-hydroxy-N,N,N-trimeth
