609-41-6Relevant academic research and scientific papers
Azabicyclic vinyl sulfones for residue-specific dual protein labelling
Gil De Montes, Enrique,Jiménez-Moreno, Ester,Oliveira, Bruno L.,Navo, Claudio D.,Cal, Pedro M. S. D.,Jiménez-Osés, Gonzalo,Robina, Inmaculada,Moreno-Vargas, Antonio J.,Bernardes, Gon?alo J. L.
, p. 4515 - 4522 (2019/04/29)
We have developed [2.2.1]azabicyclic vinyl sulfone reagents that simultaneously enable cysteine-selective protein modification and introduce a handle for further bioorthogonal ligation. The reaction is fast and selective for cysteine relative to other amino acids that have nucleophilic side-chains, and the formed products are stable in human plasma and are moderately resistant to retro Diels-Alder degradation reactions. A model biotinylated [2.2.1]azabicyclic vinyl sulfone reagent was shown to efficiently label two cysteine-tagged proteins, ubiquitin and C2Am, under mild conditions (1-5 equiv. of reagent in NaPi pH 7.0, room temperature, 30 min). The resulting thioether-linked conjugates were stable and retained the native activity of the proteins. Finally, the dienophile present in the azabicyclic moiety on a functionalised C2Am protein could be fluorescently labelled through an inverse electron demand Diels-Alder reaction in cells to allow selective apoptosis imaging. The combined advantages of directness, site-specificity and easy preparation mean [2.2.1]azabicyclic vinyl sulfones can be used for residue-specific dual protein labelling/construction strategies with minimal perturbation of native function based simply on the attachment of an [2.2.1]azabicyclic moiety to cysteine.
Gas-phase heteroaromatic substitution. 11. Electron transfer mechanism in the gas-phase acylation of simple five-membered heteroarenes
Filippi, Antonello,Occhiucci, Giorgio,Sparapani, Cinzia
, p. 740 - 748 (2007/10/02)
The results of a study of the gas-phase reactions of unsaturated carbocations, such as the CH3CO+ ion from γ-radiolysis of CH3F/CO mixtures, and the C6H4TCO+ ion from the β-decay of 1,4-ditritiobenzene in the presence of CO, with pyrrole, N-methylpyrrole, furan, and thiophene, are reported.In all systems investigated, acylated heteroarenes represent the predominant reaction products, accompanied by the methylated derivatives in the CH3F/CO radiolytic mixtures, and by the phenylated ones in the 1,4-ditritiobenzene/CO decay samples.All substrates investigated are found to undergo predominat α substitution by both acetyl (88.6-98.4percent (pyrrole); 90.8-98.7percent (N-methylpyrrole); 97.2-98.9percent (furan); 94.9-98.6percent (thiophene)) and benzoyl cations (92.6-96.5percent (pyrrole)) under all conditions.The predominant formation of the α-acylated pyrroles from both reactants (>88percent), whose relative yields appear unaffected within the temperature interval from 303 to 383 K, indicates, in agreement with ancillary FT-ICR mass spectrometric evidence, that gas-phase acylation reactions toward simple five-membered heteroarenes proceed via a two-step substitution mechanism, involving a quasi-resonant single-electron transfer (SET) step followed by recombination of the ensuing radical - radical ion pair.By virtue of this entropy-favored mechanism, gaseous electrophiles with relatively high SCF STO-3G calculated LUMO energies such CH3CO+ and C6H4TCO+ are effectively oriented toward the "soft" Cα sites of the selected heteroarenes, at variance with Klopman's Charge and Frontier Orbital Control predictions.The behavior of gaseous acylating reactants toward simple heteroarenes is discussed and compared with that of other gaseous electrophiles, whose reactivity appears instead in qualitative agreement with Klopman's model.
Reactions at high pressure. Part 15. Rates, activation parameters, and a volume profile for retro-Diels-Alder reactions in the pyrrole series
George, Adrian V.,Isaacs, Neil S.
, p. 1845 - 1848 (2007/10/02)
Thermal decomposition of N-acylpyrrole adducts of N-phenylmaleimide by a ?2s + ?2s = ?2s> route occurs at temperature below 70 deg C.Rates and activation parameters for the termolyses of endo- and exo-10-benzoyl-4-phenyl-4,10-diazatricyclo2,6>dec-8-ene-3,5-dione (6) and (7), exo-10-acetyl-4-phenyl-4,10-diazatricyclo2,6>dec-8-ene-3,5-dione (8), and endo-4-phenyl-4-aza-10-oxatricyclodec-8-ene-3,5-dione (9) have been measured at various temperatures and pressures and in various solvents.It is confirmed that the volume of activation for thermolysis of (6) is negative, consistent with a transition state more compact than either reagents or products and not accountable for in terms of dipolar character.
