87177-56-8Relevant articles and documents
Acetyl Acetone Covalent Triazine Framework: An Efficient Carbon Capture and Storage Material and a Highly Stable Heterogeneous Catalyst
Jena, Himanshu Sekhar,Krishnaraj, Chidharth,Wang, Guangbo,Leus, Karen,Schmidt, Johannes,Chaoui, Nicolas,Van Der Voort, Pascal
, (2018)
We present, for the first time, Covalent Triazine Frameworks functionalized with acetyl acetonate group (acac-CTFs). They are obtained from the polymerization of 4,4'-malonyldibenzonitrile under ionothermal conditions and exhibit BET surface areas up to 1626 m2/g. The materials show excellent CO2 uptake (3.30 mmol/g at 273 K and 1 bar), H2 storage capacity (1.53 wt% at 77 K and 1 bar) and a good CO2/N2 selectivity (up to 46 at 298 K). The enhanced CO2 uptake value and good selectivity are due to the presence of dual polar sites (N and O) throughout the material. In addition, acac-CTF was used to anchor VO(acac)2 as a heterogeneous catalyst. The V@acacCTF showed outstanding reactivity and reusability for the modified Mannich-type reaction with a higher turnover number than the homogeneous catalyst. The higher reactivity and reusability of the catalyst comes from the coordination of the vanadyl ions to the acetyl acetonate groups present in the material. The strong metalation is confirmed from Fourier Transform Infrared analysis, 13C MAS NMR spectral analysis and X-ray photoelectron spectroscopy measurement. Detailed characterization of the V@acac-CTF reveals that electron donation from O^O of the acetyl acetonate group to VO(acac)2, combined with the very high surface area of acac-CTF, is responsible for the stabilization of the catalyst. Overall, this contribution highlights the necessity of stable catalytic binding sites on heterogeneous supports to fabricate greener catalysts for sustainable chemistry.
Substituents on quinone methides strongly modulate formation and stability of their nucleophilic adducts
Weinert, Emily E.,Dondi, Ruggero,Colloredo-Melz, Stefano,Frankenfield, Kristen N.,Mitchell, Charles H.,Freccero, Mauro,Rokita, Steven E.
, p. 11940 - 11947 (2007/10/03)
Electronic perturbation of quinone methides (QM) greatly influences their stability and in turn alters the kinetics and product profile of QM reaction with deoxynucleosides. Consistent with the electron-deficient nature of this reactive intermediate, electron-donating substituents are stabilizing and electron-withdrawing substituents are destabilizing. For example, a dC N3-QM adduct is made stable over the course of observation (7 days) by the presence of an electron-withdrawing ester group that inhibits QM regeneration. Conversely, a related adduct with an electron-donating methyl group is very labile and regenerates its QM with a half-life of approximately 5 h. The generality of these effects is demonstrated with a series of alternative quinone methide precursors (QMP) containing a variety of substituents attached at different positions with respect to the exocyclic methylene. The rates of nucleophilic addition to substituted QMs measured by laser flash photolysis similarly span 5 orders of magnitude with electron-rich species reacting most slowly and electron-deficient species reacting most quickly. The reversibility of QM reaction can now be predictably adjusted for any desired application.
Copper-Induced Synthesis of Iminiums: Trimethylamine Oxidation or Amine N-Oxide Conversion
Rousselet, Guilhem,Capdevielle, Patrice,Maumy, Michel
, p. 4999 - 5002 (2007/10/02)
The ClCuIIOCuIICl reagent as well as the O2/CuIOAc system oxidize trimethylamine 1a into N,N-dimethyliminium 3a, characterized by its phenolic adduct 5a.This reaction appears to be a biomimetic model for laccase or human c
