1141-39-5Relevant articles and documents
SYNTHESIS OF SOME NEW ARYLINDOLES
Gogrichiani, E. O.,Chikvaidze, I. Sh.,Dzhibladze, L. I.,Tsotadze, M. B.,Samsoniya, Sh. A.,Suvorov, N. N.
, p. 1170 - 1173 (1994)
New indole derivatives - 2-ethoxycarbonyl-5-(p-acetylphenyl)indole and para-substituted 2-diphenylindoles - key compounds for synthesis of new bisindoles, were synthesized from 4-acetyl-4'-nitrodiphenyl.
A new cobalt triangular prism supramolecular flask: Encapsulation of a quinhydrone cofactor for hydrogenation of nitroarenes with high selectivity and efficiency
Zheng, Sijia,Zhao, Liang,Wei, Jianwei,He, Cheng,Liu, Guangzhou,Duan, Chunying
, (2019/10/16)
A new M6L3 metal-organic triangular prism host Co–L1 was synthesized that contains a sufficiently large cavity for encapsulation of a quinhydrone (QHQ) electron transporter to form charge-transfer complexes for accelerating electron delivery. Through the strong coordinating ability of the ONP chelator, a suitable redox potential was obtained for the combination of light-driven proton reduction with the selective hydrogenation of nitro groups. The experimental results showed that the regulation of redox potential is very beneficial for hydrogen production and that the introduction of QHQ accelerates electron transfer and increases the reaction rate. Control experiments based on an inhibitor and a mononuclear compound resembling the cobalt corner of the triangular prism suggest enzyme-like behaviour. This synthetic platform, in which the supramolecular systems exhibit high activity and stability, provides an alternative strategy to selectively hydrogenate nitroarenes using light as a clean energy source.
Use of "homeopathic" ligand-free palladium as catalyst for aryl-aryl coupling reactions
Alimardanov, Asaf,Schmieder-Van De Vondervoort, Lizette,De Vries, Andre H. M.,De Vries, Johannes G.
, p. 1812 - 1817 (2007/10/03)
We have previously shown that the use of ligand-free palladium employing Pd(OAc)2 as catalyst precursor in the Heck reaction of aryl bromides is possible if low catalyst loadings, typically between 0.01-0.1 mol % are used. We have now tested this phenomenon, which we have dubbed " homeopathic" palladium, in biaryl formation using the Suzuki, the Negishi and the Kumada cross-coupling reactions. The Suzuki reaction of aryl bromides, both activated and deactivated, is possible using 0.02-0.05 mol % of Pd(OAc)2. In this reaction turnover frequencies up to 30,000 have been reached with activated substrates. Even aryl chlorides could be reacted if strongly electron-withdrawing substituents were present. The Negishi coupling with a variety of arylzinc halides was possible on aryl bromides containing electron-withdrawing substituents. The Kumada reaction only gave low yields of products under "homeopathic' conditions.