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Tytuł:
Enancjoselektywna enzymatyczna desymetryzacja katalizowana oksydoreduktazami. Reakcje utleniania. Część 1
Enantioselective enzymatic desymmetrization catalyzed by oxidoreductases. Oxidation reactions. Part 1
Autorzy:
Karczmarska-Wódzka, A.
Kołodziejska, R.
Tafelska-Kaczmarek, A.
Studzińska, R.
Wróblewski, M.
Augustyńska, B.
Powiązania:
https://bibliotekanauki.pl/articles/172799.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
dehydrogenaza
monooksygenaza
reakcja utleniania
dehydrogenase
monooxygenase
oxidation reaction
Opis:
The main advantage of biotransformation involving enzymes, compared to chemical processes, is a highly selective formation of products with precise configuration. Herein we describe enzymes participating in the oxidation processes, especially dehydrogenases and monooxygenases. Dehydrogenases are not only able to catalyze the enantioselective reduction of prochiral ketones, but they can also desymmetrize meso and prochiral diols through the enantioselective oxidation. As a result of this processes, optically active hydroxyketones, hydroxycarboxylic acids, and their derivatives are obtained. Cytochrome P450 monooxygenases (CYPs) constitute a family of heme-containing enzymes which exhibits a variety of catalytic activities. They catalyze different reactions, such as hydroxylation, epoxidation, oxidative deamination, or N- and (S)-oxidation. In the oxidation reaction with monooxygenases, the whole cells are commonly used as catalysts. The use of monooxygenases in the oxidation reaction of prochiral alkanes provides the optically active alcohols. It is very significant that these transformations are still difficult to carry out by chemical methods. Baeyer-Villiger monooxygenases (BVMO EC 1.14.13.X) effectively catalyze the nucleophilic and electrophilic oxidation reactions of various functional groups. BVMO are highly regio- and stereoselective enzymes, and their catalytic potential is used in the synthesis of optically pure lactones and esters. Keywords:
Źródło:
Wiadomości Chemiczne; 2015, 69, 1-2; 35-51
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enancjoselektywna enzymatyczna desymetryzacja katalizowana oksydoreduktazami. Reakcje utleniania. Część 2
Enantioselective enzymatic desymmetrization catalyzed by oxidoreductases. Oxidation reactions. Part 2
Autorzy:
Karczmarska-Wódzka, A.
Kołodziejska, R.
Tafelska-Kaczmarek, A.
Studzińska, R.
Wróblewski, M.
Augustyńska, B.
Powiązania:
https://bibliotekanauki.pl/articles/172457.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
dioksygenaza
oksydaza
peroksydaza
reakcja utleniania
dioxygenase
oxidase
peroxidase
oxidation reaction
Opis:
In continuation of our work, we herein describe next enzyme classes applied for oxidation reaction. Dioxygenases, oxidases, and peroxidases are successfully used in the synthesis of desymmetrization products with high yields and enantiomeric excesses. Aromatic dioxygenases, such as toluene dioxygenase (TDO), naphthalene dioxygenase (NDO), and biphenyl dioxygenase (BPDO) found in the prokaryotic microorganisms are enzymes belonging to the dioxygenase class and are the most commonly used in organic synthesis. The α-oxidation of various fatty acids in the presence of an α-oxidase from germinating peas is one of the few examples of oxidases application in asymmetric organic synthesis. The intermediary α-hydroxyperoxyacids can undergo two competing reactions: decarboxylation of the corresponding aldehydes or reduction to the (R)-2-hydroxy acids. In order to eliminate the competitive decarboxylation reaction tin(II) chloride is used as an in situ reducing agent. Peroxidases are the redox enzymes found in various sources such as animals, plants, and microorganisms. Due to the fact that, in contrast to monooxygenases, no additional cofactors are required, peroxidases are highly attractive for the preparative biotransformation. Oxidation reactions catalyzed by (halo)peroxydases are also often used in organic synthesis. N-Oxidation of amines, for instance, leads to the formation of the corresponding aliphatic N-oxides, aromatic nitro-, or nitrosocompounds. From a preparative synthesis standpoint, however, sulfoxidation of thioether is important since it was proven to proceed in a highly stereo- and enantioselective manner. Furthermore, depending on the source of haloperoxidase, chiral sulfoxides of opposite configurations can be obtained.
Źródło:
Wiadomości Chemiczne; 2015, 69, 1-2; 53-64
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reakcje utleniania wybranych grup funkcyjnych z wykorzystaniem oxone® jako źródła tlenu cząsteczkowego
The oxidation reactions of selected functional groups using oxone® as a source of molecular oxygen
Autorzy:
Zawadzki, P.
Czardybon, W.
Chrobok, A.
Powiązania:
https://bibliotekanauki.pl/articles/172053.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
oxone
ciecze jonowe
reakcja utleniania
epoksyd
ionic liquids
oxidation reaction
epoxide
Opis:
Oxidation reactions belong to the group of the most commonly used processes in both organic and inorganic chemistry. The main issues in such transformation are usually safe handling of the oxidants as well as waste generation. Peroxymonosulfuric acid is one of the strongest oxidants. It was described for the first time in 1898 by Heinrich Caro. Nowadays, the commercial sources of KHSO5 are low-cost industrial bulk chemicals, e.g., the triple salt Oxone® (2KHSO5· KHSO4·K2SO4). These products are stable oxidizing agents commonly used in fine chemicals synthesis, and are easy to handle, non-toxic as well as generate non-polluting by-products. Over the past several years the scope of its use has extended. One of the most important transformation that have been made possible with the use of Oxone® are epoxidation and ketone formation. Epoxides and ketones are important synthetic building blocks widely used in the chemical industry for the production of pharmaceutical products, flavours, fragrances, resins, adhesives and paints. The use of Oxone® was demonstrated in several combinations both in classical methods that involved metal catalysis as well as in novel approaches with the use of microwaves and ionic liquids. Over the past 20 years, ionic liquids, together with supercritical fluids and water, have become powerful alternatives to conventional organic solvents. Ionic liquids are salts having in the structure an organic cation and an inorganic or organic anion, with a melting point below 100°C. The advantage of using ionic liquids is a big variety of available structures. Combinations of both ionic liquids and Oxone® offer an interesting alternative to classical oxidation methods used in industry.
Źródło:
Wiadomości Chemiczne; 2016, 70, 5-6; 289-297
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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