71236-74-3Relevant academic research and scientific papers
Changing selectivity of DNA oxidation from deoxyribose to guanine by ligand design and a new binuclear copper complex
Li, Lei,Karlin, Kenneth D.,Rokita, Steven E.
, p. 520 - 521 (2005)
A dinuclear copper complex [CuII2(PD-O)(H2O)2]3+ (1) (where PD-OH is a pyridylalkylamine containing binucleating ligand) promotes guanine oxidation in single-stranded DNA in the presence of 3-mercaptopropionic acid and dioxygen. This reaction is detected after subsequent piperidine treatment. Little spontaneous strand scission indicative of deoxyribose oxidation is observed in contrast to the results known for other copper complexes. Chemical characterization and nanospray ionization mass spectrometry analysis of oligodeoxynucleotides treated with 1 suggest conversion of guanine residues to their 2,6-diamino-5-formamidino-4-hydroxypyrimidine (+18 amu) and possibly 5,8-dihydroxy-7,8-dihydroguanine (+34 amu) derivatives. The selectivity toward nucleobase rather than deoxyribose oxidation is discussed in terms of the specific nature of the dicopper (hydro)peroxo species formed with the PD-OH ligand versus the intermediates formed in the presence of other binucleating ligands. Copyright
Catalytic Deoxygenation of Nitroarenes Mediated by High-Valent Molybdenum(VI)-NHC Complexes
Liu, Shenyu,Amaro-Estrada, Jorge Ivan,Baltrun, Marc,Douair, Iskander,Schoch, Roland,Maron, Laurent,Hohloch, Stephan
supporting information, p. 107 - 118 (2021/02/05)
The high-valent molybdenum(VI) N-heterocyclic carbene complexes, (NHC)MoO2 (1) and (NHC)MoO(NtBu) (2) (NHC = 1,3-bis(3,5-di-tert-butyl-2-phenolato)-benzimidazol-2-ylidene), are investigated toward their catalytic potential in the deoxygenation of nitroarenes. Using pinacol as the sacrificial and green reductant, both complexes are shown to be very active (pre)catalysts for this transformation allowing a reduction of the catalyst loading down to 0.25 mol %. Mechanistic investigations show μ-oxo bridged molybdenum(V) complexes [(NHC)MoO]2O (4) and [(NHC)Mo(NtBu)]2O (5) as well as zwitterionic pinacolate benzimidazolium complex 6, with a doubly protonated NHC ligand, to be potentially active species in the catalytic cycle. Both 4 and 5 can be prepared independently by the deoxygenation of 1 and 2 using triethyl phosphine (PEt3) or triphenyl phosphine (PPh3) and were shown to exhibit an unusual multireferenced ground state with a very small singlet-triplet gap at room temperature. Computational studies show that the spin state plays an unneglectable role in the catalytic process, efficiently lowering the reaction barrier of the deoxygenation step. Mechanistic details, putting special emphasis on the fate of the catalyst will be presented and potential routes how nitroarene reduction is facilitated are evaluated.
Self-assembly, crystal structure, and magnetic properties of a phenoxo- bridged tetranuclear Cu(II) complex of the [2 x 2] grid type
Rojo, Javier,Lehn, Jean-Marie,Baum, Gerhard,Fenske, Dieter,Waldmann, Oliver,Mueller, Paul
, p. 517 - 522 (2007/10/03)
The ditopic ligand 3 has been synthesized. In its deprotonated form, it reacts with copper(II) ions to form a tetranuclear complex 1 of the [2 x 2] Cu4(II) grid type, the structure of which has been confirmed by X-ray crystallography. Magnetic studies of complex 1 indicate a very weak antiferromagnetic coupling between the phenoxo-bridged Cu(II) ions.
