PaaSiCats: Novel polyamino acid catalysts

Dhanda, Anupma; Drauz, Karlheinz; Geller, Thomas; Roberts, Stanley M.

doi:10.1002/(sici)1520-636x(2000)12:5/6<313::aid-chir3>3.0.co;2-h

Cited by 34 publications

(19 citation statements)

References 17 publications

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“…These biphasic conditions constitute the most widely tested and reliable of the new class of polyamino acid catalysed epoxidation systems. Examples reported by Roberts and coworkers typically use polyleucine, however it has recently been disclosed that poly-L-neopentylglycine can offer advantages of increased reaction rate and enantioselectivity [145]. An alternative procedure employs inexpensive sodium percarbonate (NaPc) as both an oxidant and a base.…”

Section: Amino Acids and Polyamino Acidsmentioning

confidence: 99%

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

Młochowski¹

2011

TOCATJ

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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.

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Section: Amino Acids and Polyamino Acidsmentioning

confidence: 99%

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

Młochowski¹

2011

TOCATJ

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“…This very simple methodology furnished a robust catalyst, which was employed in several epoxidation reactions with a high level of enantioselectivity and without loss of activity and enantioselectivity after several cycles [12] . Further studies revealed that in addition to pLL, poly neo -pentylglycine (pLN) immobilized on silica gel also furnished excellent results (Scheme 2.2 ) [15] . An improved protocol for the preparation and activation of the pLL catalyst for subsequent immobilization on silica gel was later reported [14] .…”

Section: Noncovalently Linked: Silicamentioning

confidence: 99%

Recyclable Organocatalysts in Asymmetric Reactions

Gruttadauria

Giacalone

Noto

2011

Catalytic Methods in Asymmetric Synthesis

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“…Eine Lösung des Problems besteht darin, den Katalysator auf Polymer‐159 oder Kieselgel‐Trägern160 zu adsorbieren. Dieses Vorgehen ermöglicht nicht nur die einfache Abtrennung des Katalysators, sondern bewirkt zudem eine Beschleunigung der Reaktion und oft sogar eine Erhöhung der Enantioselektivität 160c…”

Section: Di‐ Und Polypeptide Als Chirale Makromolekulare Katalysatunclassified

Asymmetrische heterogene Katalyse

2006

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Knapper werdende Rohstoffe und ein zunehmender Bedarf an enantiomerenreinen Verbindungen machen die Katalyse und insbesondere die heterogene asymmetrische Katalyse zu einer Schlüsseltechnologie. Von den Anfängen, der Verwendung chiraler Biopolymere wie Seide als Träger für Metallkatalysatoren, zu den modernen Forschungsfeldern hat sich das Gebiet rasant entwickelt. Mesoporöse Träger, nichtkovalente Immobilisierung, metall‐organische Katalysatoren, chirale Modifikatoren: viele Gebiete sind im Aufbruch. Dass hierbei von den Katalysatoren mehr geleistet wird, als nur leichte Abtrennung und Wiederverwendung zu ermöglichen, zeigt dieser Aufsatz. So können z. B. bessere Aktivitäten und Selektivitäten als bei der homogenen Katalyse und zudem neuartige, effiziente Reaktionsmechanismen erhalten werden. Besonders spektakulär ist aber der Ausblick auf hochgeordnete metall‐organische Katalysatoren, die “rational” entwickelt, synthetisiert und strukturell eindeutig charakterisiert werden können, um maßgeschneiderte Katalysatoren zu erhalten.

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PaaSiCats: Novel polyamino acid catalysts

Cited by 34 publications

References 17 publications

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

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

Recyclable Organocatalysts in Asymmetric Reactions

Asymmetrische heterogene Katalyse

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