Catalytic asymmetric and chemoselective aerobic oxidation: kinetic resolution of sec-alcohols

Katsuki Catalysts for Asymmetric Oxidation: Design Concepts, Serendipities for Breakthroughs, and Applications

“…31, 34 His deep insight into the catalytic cycle relied on the detailed kinetic analysis 38c and the rational ligand design finally led to the development of unprecedented catalytic highly enantioselective oxidation reactions, including alcohol oxidation (OKR), 34,3638 oxidative 2-naphthol coupling, 41 sulfoxidation, 44 and alkene epoxidation, 44,45 with the Ru-salen complexes K3 RS and K3 RR and O 2 in air or a balloon under photoirradiation of visible light. Furthermore, he also attained catalytic asymmetric aerobic oxidation of alkenes without photoirradiation, in a way mechanistically comparable to a biological oxidation system.…”

“…In addition, this oxidation proceeded in an enantiomer-differentiating manner so that the alcohol intact was enantioenriched. This was the moment that he finally attained a catalytic asymmetric aerobic oxidation reaction, 34 which he had actually long desired. He was really happy with this serendipity.…”

“…Under the optimized conditions with K3 RR upon irradiation with visible light, not only activated alcohols but also a non-activated aliphatic alcohol were oxidized in air with good to high levels of k rel (Table 1) as the first example of OKR engaged by a chiral molecular catalyst and O 2 without any additive such as co-reductant. 34,35 Afterward, a diketone was found to serve as co-catalyst for enhancing k rel significantly. 36 Furthermore, his continuous efforts to optimize the ligand structure led to the recent finding of a Ru-salen catalyst, which promoted OKR of a range of secondary alcohols in the dark with further increased k rel up to 60.…”

Asymmetric Transformations by Coupled Enzyme and Metal Catalysis: Dynamic Kinetic Resolution

“…Chiral Ru(II) complexes formed from [RuCl 2 ( p -cymene)] 2 and chiral bidentate nitrogen ligands have been extensively studied as catalysts for the asymmetric transfer hydrogenation of prochiral ketones [21] . Sheldon et al utilized an achiral analog 4 for alcohol racemization.…”

High-resolution infrared spectroscopy and analysis of the ν2/ν4 bending dyad of ruthenium tetroxide

“…It is a heavy tetrahedral molecule, but is relatively volatile with a notable vapor pressure at room temperature. It is also a powerful oxidant and can be used in oxidation reactions [1,2]. RuO 4 is quite reactive at room temperature and decomposes readily to produce RuO 2 films, which is used in the semiconductor industry [3].…”