1105576-13-3Relevant articles and documents
Quinone Reduction by Organo-Osmium Half-Sandwich Transfer Hydrogenation Catalysts
Bolitho, Elizabeth M.,Coverdale, James P. C.,Sadler, Peter J.,Schünemann, Volker,Wolny, Juliusz A.,Worby, Nathan G.
, p. 3012 - 3023 (2021/09/13)
Organo-osmium(II) 16-electron complexes [OsII(η6-arene)(R-PhDPEN)] (where η6-arene =para-cymene or biphenyl) can catalyze the reduction of prochiral ketones to optically pure alcohols in the presence of a hydride source. Such complexes can achieve the conversion of pyruvate to unnatural http://www.w3.org/1999/xlinkd-lactate in cancer cells. To improve the catalytic performance of these osmium complexes, we have introduced electron-donor and electron-acceptor substituents (R) into thepara(R1) ormeta(R2) positions of the chiral R-phenyl-sulfonyl-diphenylethylenediamine (R-PhDPEN) ligands and explored the reduction of quinones, potential biological substrates, which play a major role in cellular electron transfer chains. We show that the series of [OsII(η6-arene)(R-PhDPEN)] derivatives exhibit high turnover frequencies, enantioselectivities (>92%), and conversions (>93%) for the asymmetric transfer hydrogenation (ATH) of acetophenone-derived substrates and reduce duroquinone and menadione to their di-alcohol derivatives. Modeling of the catalysis using density functional theory (DFT) calculations suggests a mechanism involving formic acid deprotonation assisted by the catalyst amine groups, phenyl-duroquinone stacking, hydride transfer to OsII, possible CO2coordination, and tilting of the η6-arene ring, followed by hydride transfer to the quinone. These findings not only reveal subtle differences between Ru(II) and Os(II) catalysts, but also introduce potential biological applications.
Ruthenium(II)-Catalyzed Enantioselective ?-Lactams Formation by Intramolecular C-H Amidation of 1,4,2-Dioxazol-5-Ones
Xing, Qi,Chan, Chun-Ming,Yeung, Yiu-Wai,Yu, Wing-Yiu
supporting information, (2019/03/11)
We report the Ru-Catalyzed enantioselective annulation of 1,4,2-Dioxazol-5-Ones to furnish ?-Lactams in up to 97% yield and 98% ee via intramolecular carbonylnitrene C-H insertion. By employing chiral diphenylethylene diamine (dpen) as ligands bearing electron-Withdrawing arylsulfonyl substituents, the reactions occur with remarkable chemo- A nd enantioselectivities; the competing Curtius-Type rearrangement was largely suppressed. Enantioselective nitrene insertion to allylic/propargylic C-H bonds was also achieved with remarkable tolerance to the Ca?C and Ca‰iC bonds.
A four-hydrogenated 1, 8 - naphthyridine apperception composition preparation method and its prepared chiral products
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Paragraph 0137; 0173, (2018/03/26)
The invention discloses a preparation method of a tetrahydro 1, 8-naphthyridine compound. The preparation method comprises the following steps: under the existence of a chiral catalyst, enabling a compound with the structure shown in the formula (1) (in the description) and hydrogen to be subjected to addition reaction, wherein the chiral catalyst is a coordination compound with the structure shown in the formula (2) (in the description). The invention further provides a chiral product of the tetrahydro 1, 8-naphthyridine compound, prepared through the preparation method. According to the invention, the proper compound with the structure shown in the formula (1) (in the description) is used as a substrate, and the proper coordination compound with the structure shown in the formula (2) (in the description) is used as the chiral catalyst to perform selective hydrogenation reduction on 1, 8-naphthyridine compound with the structure shown in the formula (1) by adopting hydrogen, so that the chiral product of the tetrahydro 1, 8-naphthyridine compound is prepared with low cost. The chiral product of the tetrahydro 1, 8-naphthyridine compound can be used as a biologically active compound and a structural building block of a chiral drug.
