Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "synteza organiczna" wg kryterium: Temat


Tytuł:
Preparation of conjugated nitroalkenes: short review
Autorzy:
Zawadzińska, Karolina
Gaurav, Gajendra Kumar
Jasiński, Radomir
Powiązania:
https://bibliotekanauki.pl/articles/35110314.pdf
Data publikacji:
2022
Wydawca:
Radomskie Towarzystwo Naukowe
Tematy:
nitroalkenes
organic synthesis
nitrocompounds
nitroalkeny
synteza organiczna
nitrozwiązki
Opis:
Key protocols of the preparation of conjugated nitroalkenes were reviewed and critically discussed. It was established, that optimal strategy for the obtaining of target compounds are small molecules extrusion processes from saturated nitro-compounds. Among them, the most universal methodologies based on carboxylic acids elimination have been discussed, which provide for smooth applications.
Źródło:
Scientiae Radices; 2022, 1, 1; 69-83
2956-4808
Pojawia się w:
Scientiae Radices
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mikrofale w syntezie organicznej: historia i perspektywy
Autorzy:
Lipińska, T. M
Powiązania:
https://bibliotekanauki.pl/articles/273516.pdf
Data publikacji:
2013
Wydawca:
Roble
Tematy:
mikrofale
promieniowanie mikrofalowe
technika mikrofalowa
synteza organiczna
microwaves
microwave radiation
microwave techniques
organic synthesis
Źródło:
LAB Laboratoria, Aparatura, Badania; 2013, 18, 4; 6-10
1427-5619
Pojawia się w:
LAB Laboratoria, Aparatura, Badania
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowoczesne metody pozyskiwania substancji biologicznie aktywnych przy zastosowaniu reakcji wieloskładnikowych ze szczególnym uwzględnieniem reakcji Ugi
New methods of receive biologically active substances in multicomponent reactions with particular focus on Ugi reaction
Autorzy:
Ryng, S.
Jęśkowiak, I.
Powiązania:
https://bibliotekanauki.pl/articles/172211.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
reakcja wieloskładnikowa
reakcja Ugi
synteza organiczna
synteza ukierunkowana na różnorodność
multicomponent reaction
Ugi reaction
diversity-oriented synthesis
Opis:
In the last decade a change of thought has taken place in the pharmaceutical industry which has led to a renaissance of the Multicomponent reactions (MCRs) [1]. Under the inspiration of diversity-oriented-synthesis (DOS), numerous efforts have been devoted to find powerful synthetic tools for rapidly accessing maximum molecular diversity with minimum cost. In the toolbox enabling DOS for generating molecular libraries, MCRs are now recognized as one of the most useful and powerful strategies [2], which provide the highest number of compounds for the least synthetic effort [3]. Following the rapid progress in the research area of MCRs, widespread application has been found in many different areas such as chemical biology, natural product synthesis, pharmaceuticals as well as agrochemistry [2]. The overall aim of a DOS is to generate a small-molecule collection with a high degree of structural, and thus functional, diversity that interrogates large areas of chemical space simultaneously [4]. In Targed-Oriented Synthesis (TOS) a complex target is transformed into a sequence of progressively simpler structures by formally performing chemical reactions in the reverse-synthetic direction [3]. Special subclasses are isocyanide based MCRs (IMCRs). They are particularly interesting because they are more versatile and diverse than the remaining MCRs. Today most MCRs chemistry performed with isocyanides relates to the classical reactions of Passerini and Ugi (Scheme 1)[5]. In Ugi four-component reaction (U-4CR), carboxylic acids, primary amines and oxo components (aldehydes or ketones) react with isocyanides in polar solvents to obtain -amino carboxamides (Schemes 2 and 3). Occasionally however, selective conversion of amide groups into other functional groups is desirable for an increase of diversity of the IMCR-derived compounds [6]. In this reaction two substituted amide groups are formed under release of one equivalent of water. Thus, the U-4CR is an atom-economic and environmentally friendly reaction. It was also shown that water can be used as the solvent. This reaction is typically performed by stirrling the components for approximately 1 day in small quantities of a protic solvent (e.g. methanol or trifluoroethanol) [7]. The examples of Ugi reactions are described in the Schemes 4–10. Multicomponent reactions have become attractive tools in modern synthetic organic chemistry. Among their many advantages, they allow the creation of large chemical libraries of diverse, complex molecular structures, starting from simple materials within a short time frame. Not surprisingly, these particular features have made MCRs especially appealing to medicinal chemists [8].
Źródło:
Wiadomości Chemiczne; 2017, 71, 1-2; 45-63
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kwas winowy i jego pochodne we współczesnej chemii organicznej
Tartaric acid and its derivatives in current organic chemistry
Autorzy:
Grajewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/171622.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
kwas winowy
winiany
stereochemia
synteza organiczna
kataliza
tartaric acid
tartrates
stereochemistry
organic synthesis
catalysis
Opis:
The tartaric acid and its salts have been present in chemistry for almost 350 years, since Pierre Seignette isolated Rochelle salt in 1675. Since that time tartaric acid and its derivatives have been often used in chemistry due to their accessibility, enantiopurity, relatively low cost and presence of different functional groups which easily allow to modify the molecule. Many tartaric acid derivatives serve as catalysts in important stereoselective transformations such as Sharpless asymmetric epoxidation or asymmetric Rousch aryloboronation. In many others reactions tartaric acid have been employed as a chiral building block for natural products synthesis, highly functionalized molecules or ligand design such as well known TADDOL or its analogues. Its polar functional groups allow to form crystals with amines and aminoalcohols what is widely used for their enantiopurification and resolution. The relatively new subdiscipline is the use of tartaric acid in chiral recognition and chiral discrimination in nanochemistry and enantioselective chromatography. The other, recent applications of tartaric acid include functionalization of metal layers, antibacterial and antifungal activity among many others. The significance of tartaric acid is evident – since 2000, words “tartaric acid” or “tartrates” can be found in databases over four thousand times. Taking that into account this short review is concentrated on selected applications of tartaric acid and its derivatives in organic chemistry in recent several years.
Źródło:
Wiadomości Chemiczne; 2013, 67, 5-6; 495-519
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania enzymów z tkanek zwierzęcych w syntezie organicznej i biokatalizie. Część I. Hydrolazy
Applications of hydrolases from animal tissues in organic synthesis
Autorzy:
Hibner, H.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172016.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
enzymy zwierzęce
biokataliza
synteza organiczna
zastosowania hydrolaz
animal enzymes
biocatalysis
organic synthesis
applications of hydrolases
Opis:
This work presents systematically enzymes which can be obtained form animal tissue and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory. Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were done. In this part typical applications of hydrolases: lipases (porcine pancreatic lipase [8–17], lamb pregastric lipase [22]), esterases (porcine, horse liver esterase, liver acetone powders [34–43, 46]), L-aminoacylase [48, 49], pepsin [56], trypsin [58, 59], imidase [52, 53], aldohexose hydrolases [60, 62-64], nucleotide pyrophosphatase [65]; were described. Also examples of immobilized [10, 32] or recombined [49] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes. In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms.
Źródło:
Wiadomości Chemiczne; 2011, 65, 7-8; 557-583
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowania wybranych enzymów z tkanek zwierzęcych w syntezie organicznej i biokatalizie. Część II. Oksydoreduktazy, transferazy, liazy, izomerazy
Applications of enzymes from animal tissues in organic synthesis, Part 2
Autorzy:
Hibner, H.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172018.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
enzymy zwierzęce
biokataliza
synteza organiczna
zastosowania enzymów
animal enzymes
biocatalysis
organic synthesis
application of enzymes
Opis:
This work shows systematically known types of animal enzymes and their applications in synthesis of pharmaceuticals and nonracemic organic compounds. It lays out similarities in procedures of isolation and purification of particular enzymes. Such procedures usually are so simple that they can be used in every industrial or research laboratory. Most animal enzymes are well-investigated and their structures and substrate specificity are known. They are used as biocatalysts in many chemical processes. Others were used in one or a few reactions but their natural substrates and biochemical properties are described. Trials of predicting potential applications of such enzymes and other substrates for them were performed. Typical applications of: – Oxidoreductases: horse liver alcohol dehydrogenase [3–13], lactate dehydrogenase [16–18], glutamate dehydrogenase [19, 20], carbonyl reductase [24], catalase [27]; – Transferases: transaldolase [29], galactosyltransferase [30], UDP-glucuronosyltransferase [31], fucosyltransferase [34], farnesyl diphosphate synthase [35]; – Lyases: DOPA decarboxylase [38, 39], aldolase [42]; – Isomerases: N-acyl-D-glucosamine 2-epimerase [44] were described. Also examples of or recombined [24, 39, 44] enzymes are given in the text. These modifications enhance catalytic properties or reduce costs of using enzymes. In practical applications a biocatalytic effect of enzymes from animal sources is often compared with microbial ones. This text is focused on processes where animal enzymes gave much better results (yield and enantioselectivity) than microorganisms. They are also proper, unlike whole microorganisms, to investigate and computer analysis of mechanism of the reaction. Enzymes isolated from animal tissues usually have well-defined structure of active site which is a key to predict mechanisms. A quantitative analysis of applications of these enzymes was performed. Among animal enzymes hydrolases and oxidoreductases have found the most applications in synthesis. Transferases are also often used. Other classes of enzymes seldom act as biocatalysts. It is general tendency, true also in relation to microbial and plant enzymes.
Źródło:
Wiadomości Chemiczne; 2011, 65, 7-8; 585-607
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biokatalityczne metody otrzymywania nieracemicznych alkoholi aryloallilowych
Biocatalytic methods for preparation of nonracemic arylallylic alcohols
Autorzy:
Szymkuć, S.
Ostaszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/172469.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
biokataliza
nieracemiczne alkohole aryloallilowe
synteza organiczna
enzymy
mikroorganizmy
biocatalysis
nonracemic arylallylic alcohols
organic synthesis
enzymes
microorganisms
Opis:
Different methods for preparing nonracemic arylallylic alcohols are presented in this work. A key feature was an application the biocatalyst as a mean to obtain final products. These compounds play an important role in pharmaceutical industry, because they are substrates in the synthesis of various important therapeutics [1–3]. Methods presented in this work are divided into five main groups: 1. enantioselective hydroxylation, 2. microbiological deracemization, 3. enzymatic kinetic resolution, 4. enzymatic dynamic kinetic resolution, 5. enantioselective reduction. First two methods use only microorganisms like bacteria [4, 5, 10], fungi [6–8] or yeasts [11] as biocatalysts. Owing to the metabolic processes in the cells it was possible to obtain nonracemic arylallylic alcohol (results for method 2 are presented in Table 1). Unfortunately, the data were insufficient to create direct correlation between values of enantiomeric excess and types of applied microorganisms. Methods 3 and 4 used only isolated enzymes as biocatalysts. They belong to two classes: hydrolases and oxidoreductases. Oxidoreductases were used in the enzymatic kinetic resolution based on the enantioselective oxidation [28] of one enantiomer of the racemic arylallylic alcohol. Nevertheless, hydrolases [12–27], mainly lipases, isolated from microorganisms are enzymes of common use in enzymatic kinetic resolution. Owing to this method it was possible to obtain final products with excellent enantioselectivity (results are presented in Tables 2 and 3). Because kinetic resolution and dynamic kinetic resolution are related processes, in most cases similar enzymes are used. The choice of lipases as biocatalysts for method 4 was caused by the fact that they are able to catalyze enantioselective transesterification of arylallylic alcohols or their acetates. Furthermore, racemization is very important factor for efficacy of dynamic kinetic resolution processes. In most cases they are catalyzed by different types of complexes based on palladium [30, 31] and ruthenium [32, 34]. Final products prepared by this method had very high enantiomeric excesses and yields up to 93% (results are presented in Tables 4 and 5). The only method, presented in this work, that allowed to use both enzymes [39–41] and microorganisms [35–38] as biocatalysts, was enantioselective reduction. This method allows to obtain nonracemic arylallylic alcohols with excellent enantiomeric excess and yields up to 85% (results are presented in Table 6). In summary, all methods presented in this work show the advantages of biocatalysis as an alternative route to traditional chemical method
Źródło:
Wiadomości Chemiczne; 2012, 66, 1-2; 93-118
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anion alkoksyallenowy w syntezie związków naturalnych i ich analogów
Alkoxyallene anion in the synthesis of natural products and their analogues
Autorzy:
Busiak, B.
Utecht, G.
Jasiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/172377.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
alkoksyalleny
addycja nukleofilowa
synteza organiczna
związki naturalne
związki heterocykliczne
alkoxyallenes
nucleophilic addition
organic synthesis
natural products
heterocycles
Opis:
Among diverse systems containing multiple bonds, cumulenes are recognized as the most reactive derivatives towards both nucleophilic and electrophilic agents, and for this reason, they are considered as important class of substrates for organic synthesis. Over the last three decades alkoxyallenes have been demonstrated as highly useful C3-building blocks for the construction of numerous N-, O-, and S-containing heterocycles, including enantiomerically pure compounds. Special attention has been paid to lithiated alkoxyallenes as suitable nucleophiles for the reactions with alkyl halides, strained heterocycles, carbonyl compounds and their derivatives. The presence of the allene unit in the initially formed adducts opens up several possibilities in the preparation of more complex systems. In this review, selected applications of lithiated alkoxyallenes in the synthesis of natural products and their analogues are discussed.
Źródło:
Wiadomości Chemiczne; 2016, 70, 1-2; 3-23
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bezpośrednia synteza azydków i tioli organicznych pochodnych glikolu etylenowego w zmodyfikowanej reakcji Appela
Direct synthesis of organic azides and thiols derived from ethylene glycol via modified Appel reaction 1
Autorzy:
Stefaniak, M.
Jasiński, M.
Urbaniak, K.
Romański, J.
Seliger, P.
Gutowska, N
Powiązania:
https://bibliotekanauki.pl/articles/141899.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
synteza organiczna
tiole
azydki
reakcja „click”
makrocykle
kompleksy metali
organic synthesis
thiols
azides
click reaction
macrocycles
metal complexes
Opis:
Klasyczną metodę konwersji alkoholi pierwszorzędowych w odpowiednie halogenki alkilowe z użyciem trifenylofosfiny oraz tetrahalogenometanu, tzw. reakcję Appela, zaadoptowano do bezpośredniej syntezy terminalnych tioli i azydków organicznych pochodnych glikolu etylenowego oraz jego siarkowego analogu. W kluczowym etapie opisanej procedury one-pot, otrzymane in situ, w reakcji z N-bromosukcynimidem (NBS), odpowiednie dibromopochodne zostały przekształcone w związki docelowe w reakcji z nukleofilem siarkowym lub azotowym. Wybrane diazydki wykorzystano w syntezie nowych układów makrocyklicznych, które przetestowano pod kątem ich właściwości kompleksotwórczych.
Classical method of conversion of primary alcohols into corresponding alkyl halides by usage of triphenylphosphine and tetrahalogenated methane, so-called Appel reaction, was adopted for the direct synthesis of terminal organic thiols and azides derived from ethylene glycol and its sulfurated analogue. In key step of the presented ‘one-pot’ protocol, corresponding dibromides, generated in situ via reaction with N-bromosuccinimide (NBS), were converted into desired products by treatment with appropriate sulfur or nitrogen nucleophile. A series of diazides and dithiols derived from (poly)ethylene glycols and their sulfur analogues were obtained. Selected diazides were utilized for the construction of novel macrocyclic systems, that were tested incontext of their complexing properties.
Źródło:
Chemik; 2014, 68, 7; 592-599
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ditlenek węgla w syntezie organicznej
Carbon dioxide in organic synthesis
Autorzy:
Burczyk, B.
Powiązania:
https://bibliotekanauki.pl/articles/172758.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
wiązanie ditlenku węgla
surowce odnawialne
synteza organiczna
kataliza
kompleksy metali przejściowych
carbon dioxide fixation
renewable resources
organic synthesis
catalysis
transition metal complexes
Opis:
Carbon dioxide is an abundant, cheap, almost nontoxic, thermodynamically stable, inert electrophile. Exploitation of CO 2 as a chemical feedstock, although will almost certainly not reduce its atmospheric concentration significantly, aims to generate high-value products and more-efficient processes. In recent years efficient transition-metal complexes have been used to perform homogeneously catalyzed transformations of CO 2 . This paper presents an overview of available catalytic routes for the synthesis of carboxylic acids, lactones, urea and carbamates, linear and cyclic carbonates as well as polycarbonates. Reduction processes of CO 2 are shortly men - tioned as well. C arboxylic acids have been synthesized via : (i) carboxylation of organolithium, organomagnesium (Scheme 2 [35]), organoboron (Scheme 3 [40 -42]), organozinc (Scheme 4 [43, 44]) and organotin (Scheme 5 [45, 46]) compounds; (ii) oxidative cycloaddition of CO 2 to olefins and alkynes (Scheme 6 -10 [47 -50, 57]) catalyzed by Ni(0)-complexes; (iii) transition-metal catalyzed reductive hydrocarboxylation of unsaturated compounds (Scheme 11, 12 [64 -67]); (iv) carboxylation of C-H bond (Scheme 13 [69 -71]). Telomerization of dienes, for instance 1,3-butadiene, and CO 2 in the presence of Ni(II) and Pd(II) complexes leads to lactones and esters of carboxylic acids (Scheme 14, 15 [73 -79]). Nucleophilic ammonia, primary and secondary amines react with CO 2 to give, respectively, urea and carbamic acid esters - carbamates and isocyanates (Scheme 16 -18 [94, 95]), thus eliminating the use of phosgene in their synthesis. CO 2 reacts with alcohols, diols and epoxides in the presence of transition-metal complexes (Fig. 2) and the reaction products are: linear carbonates (Scheme 20, 21 [110 -118]), cyclic carbonates (Scheme 22 -24 [153 -170]) and polycarbonates (Scheme 25, 26, Fig. 3, Tab. 1 [179 -186]). Finally, hydrogenation of CO 2 , leading to the formation of CO, HCOOH, CH 3 OH, CH 4 , C 2 H 6 and C 2 H 4 (Scheme 27), as well as electrochemical and photochemical reductions in the pre - sence of homogeneous and heterogeneous catalysts have been shortly reviewed.
Źródło:
Wiadomości Chemiczne; 2013, 67, 1-2; 1-53
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies