49764-93-4Relevant academic research and scientific papers
Artificial photosynthetic reaction center with a coumarin-based antenna system
Garg, Vikas,Kodis, Gerdenis,Liddell, Paul A.,Terazono, Yuichi,Moore, Thomas A.,Moore, Ana L.,Gust, Devens
, p. 11299 - 11308 (2013)
In photosynthesis, sunlight is absorbed mainly by antenna chromophores that transfer singlet excitation energy to reaction centers for conversion to useful electrochemical energy. Antennas may likewise be useful in artificial photosynthetic systems that u
Tetraaryl Cyclopentadienones: Experimental and Theoretical Insights into Negative Solvatochromism and Electrochemistry
Meitinger, Nicolas,Mengele, Alexander K.,Witas, Kamil,Kupfer, Stephan,Rau, Sven,Nauroozi, Djawed
, p. 6555 - 6562 (2020/10/02)
The synthesis of a series of tetraaryl cyclopentadienones comprising different substitution patterns is reported. Their photophysical and electrochemical properties are investigated by UV/Vis spectroscopy and cyclic voltammetry as well as by supporting quantum chemical simulations and reveal a distinct effect of substituents on the redox behavior of the molecules as well as the absorption properties of this class of compounds. While electrochemical data display a shift in reduction potential of up to 200 mV between the differently substituted cyclopentadienones, their photophysical investigations in differently polar solvents suggest a negative solvatochromic effect, although protic solvents induce a bathochromic shift. Crystal structure analyses of some derivatives confirm similarity with related cyclopentadienones while providing insight into intermolecular C–H···O and C–H···π interactions in the solid state.
Racemisation of 1-arylethylamines with Shvo-type organoruthenium catalysts
Apps, James F. S.,Livingston, Andrew G.,Parrett, Mark R.,Pounder, Ryan J.,Taylor, Paul C.,Turner, Andrew R.
, p. 1391 - 1394 (2014/06/23)
Variation of the electronic nature of the tetraphenylcyclopentadienone ligand in organoruthenium complexes influences their utility for racemisation of model chiral amines. Our study highlights the need to balance reactivity and selectivity in the design of racemisation catalysts. Electron-poor Shvo-type catalysts are, at first sight, more effective for racemisation, but yield more by-product; electron-rich complexes are less proficient at racemisation, but lead to less by-product.
Tuning of the electronic properties of a cyclopentadienylruthenium catalyst to match racemization of electron-rich and electron-deficient alcohols
Verho, Oscar,Johnston, Eric V.,Karlsson, Erik,Baeckvall, Jan-E.
, p. 11216 - 11222 (2011/11/05)
The synthesis of a new series of cyclopentadienylruthenium catalysts with varying electronic properties and their application in racemization of secondary alcohols are described. These racemizations involve two key steps: 1) β-hydride elimination (dehydrogenation) and 2) re-addition of the hydride to the intermediate ketone. The results obtained confirm our previous theory that the electronic properties of the substrate determine which of these two steps is rate determining. For an electron-deficient alcohol the rate-determining step is the β-hydride elimination (dehydrogenation), whereas for an electron-rich alcohol the re-addition of the hydride becomes the rate-determining step. By matching the electronic properties of the catalyst with the electronic properties of the alcohol, we have now shown that a dramatic increase in racemization rate can be obtained. For example, electron-deficient alcohol 15 racemized 30 times faster with electron-deficient catalyst 6 than with the unmodified standard catalyst 4. The application of these protocols will extend the scope of cyclopentadienylruthenium catalysts in racemization and dynamic kinetic resolution. Copyright
Efficient synthesis of substituted polyarylphthalimides via cycloaddition of cyclopentadienones with 2-bromomaleimide
Vanel, Rémi,Berthiol, Florian,Bessières, Bernard,Einhorn, Cathy,Einhorn, Jacques
, p. 1293 - 1295 (2011/07/07)
Functionalized tetraarylphthalimides or diarylphthalimides fused with an acenaphthene moiety have been prepared in one step from 2-bromomaleimide and tetraarylcyclopentadienones (tetracyclones) or 7,9-diaryl-8H- cyclopentacenaphthylene-8-ones (acecyclones
Fast DKR of amines using isopropyl 2-methoxyacetate as acyl donor
Veld, Martijn A. J.,Hult, Karl,Palmans, Anja R. A.,Meijer
, p. 5416 - 5421 (2008/03/18)
The dynamic kinetic resolution (DKR) of various primary amine substrates was performed using a modified version of the Baeckvall system. A single equivalent of isopropyl 2-methoxyacetate was used as acyl donor in combination with p-MeO Shvo complex as the racemization catalyst and Novozym 435 as the acylation catalyst. A reaction temperature of 100°C was employed to ensure a high racemization rate. Adding 2,4-dimethyl-3-pentanol (DMP) as hydrogen donor at a concentration of 0.5 M successfully suppressed side product formation. Under these modified DKR conditions, complete conversion was observed for most substrates within 26 h showing both high ee values and good chemoselectivity, whereas the original system required a reaction time of 72 h. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
