PaaSicats: Powerful catalysts for asymmetric epoxidation of enones. Novel syntheses of α-arylpropanoic acids including (S)-fenoprofen

Carde, Lydia; Davies, Huw; Geller, Thomas; Roberts, Stanley M.

doi:10.1016/s0040-4039(99)01022-9

Cited by 57 publications

(17 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was found that silica provided the best combination of improved activity and ease of filtration/recycling. Generally the silica-adsorbed material is active enough to allow as little as 2.5 mol% catalyst (based on 1 equivalent being a single polyamino acid chain) to be used without any reduction in enantioselectivity [147,148]. The polyleucine catalyzed epoxidation shows some interesting selectivity.…”

Section: Amino Acids and Polyamino Acidsmentioning

confidence: 99%

Non-Metal and Enzymatic Catalysts for Hydroperoxide Oxidation of Organic Compounds

Młochowski¹

2011

TOCATJ

View full text Add to dashboard Cite

Oxidation of different groups of organic compounds, with hydroperoxides catalyzed by non-heavy metal containing low-molecular-weight compounds and enzymes is reviewed. This article is concentrated mainly on the hydrogen peroxide and tert-butyl hydroperoxide, however other less common hydroperoxides are also mentioned. Since hydroperoxides themselves are inactive toward most of the organic substrates, in situ activation of the oxidant is necessary. For this purpose various activators have been applied in stoichiometric or catalytic amounts. The carboxylic acids, nitriles, amides and urea are representative for the first category. The organocatalysts such as-halo carbonyl compounds, ketones, imines, iminium salts, nitroxyl radicals and polyaminoacids, selenium compounds and enzymes are presented. They are involved in oxygen, and electron transfer processes whose mechanisms are briefly discussed, and their applications in laboratory and industrial synthesis are indicated.

show abstract

Section: Amino Acids and Polyamino Acidsmentioning

confidence: 99%

Non-Metal and Enzymatic Catalysts for Hydroperoxide Oxidation of Organic Compounds

Młochowski¹

2011

TOCATJ

View full text Add to dashboard Cite

show abstract

“…Further improvement both of the activity of the catalyst and of its ease of handling and recycling was achieved by immobilization on polystyrene supports [78] and, in particular, on silica gel [79,80]. The latter procedure affords ''poly-amino acids on silica catalysts'', the so-called ''PaaSiCats''.…”

Section: Epoxidation Of Enones and Enoatesmentioning

confidence: 99%

Oxidation

2005

Asymmetric Organocatalysis

View full text Add to dashboard Cite

show abstract

“…50 In other related work, Carde et al have applied this methodology to the synthesis of arylpropionic acids, making use of polyleucine absorbed onto silica. 51 The importance of an α-helical catalyst structure has been suggested in these reactions, and indeed incorporation of α-aminoisobutyric acid into leucine oligomers does give effective catalysts. 52 Possibly the simplest protocol for asymmetric epoxidation of an electron-deficient alkene involves base-mediated reaction with a chiral hydroperoxide (Weitz-Scheffer epoxidation).…”

Section: Three-membered Ringsmentioning

confidence: 99%