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Organocatalysis is a very useful tool for the asymmetric synthesis of biologically or pharmacologically active compounds because it avoids the use of noxious metals, which are difficult to eliminate from the target products. Moreover, in many cases, the organocatalysed reactions can be performed in benign solvents and do not require anhydrous condi...
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... Recycling of these complex catalysts was inconsistently reported. Despite their synthesis challenges, the potential of highly functionalized sugar-based organocatalysts remains underexplored, suggesting opportunities in diastereoselective preparations from simpler chiral substrates like carbohydrates and amino acids (Wojaczyńska et al., 2021). Another study delves into the preparation conditions of HZSM-5/MCM-41 composite molecular sieves. ...
Algal polysaccharides, harnessed for their catalytic potential, embody a compelling narrative in sustainable chemistry. This review explores the complex domains of algal carbohydrate-based catalysis, revealing its diverse trajectory. Starting with algal polysaccharide synthesis and characterization methods as catalysts, the investigation includes sophisticated techniques like NMR spectroscopy that provide deep insights into the structural variety of these materials. Algal polysaccharides undergo various preparation and modification techniques to enhance their catalytic activity such as immobilization. Homogeneous catalysis, revealing its significance in practical applications like crafting organic compounds and facilitating chemical transformations. Recent studies showcase how algal-derived catalysts prove to be remarkably versatile, showcasing their ability to customise reactions for specific substances. Heterogeneous catalysis, it highlights the significance of immobilization techniques, playing a central role in ensuring stability and the ability to reuse catalysts. The practical applications of heterogeneous algal catalysts in converting biomass and breaking down contaminants, supported by real-life case studies, emphasize their effectiveness. In sustainable chemistry, algal polysaccharides emerge as compelling catalysts, offering a unique intersection of eco-friendliness, structural diversity, and versatile catalytic properties. Tackling challenges such as dealing with complex structural variations, ensuring the stability of the catalyst, and addressing economic considerations calls for out-of-the-box and inventive solutions. Embracing the circular economy mindset not only assures sustainable catalyst design but also promotes efficient recycling practices. The use of algal carbohydrates in catalysis stands out as a source of optimism, paving the way for a future where chemistry aligns seamlessly with nature, guiding us toward a sustainable, eco-friendly, and thriving tomorrow. This review encapsulates—structural insights, catalytic applications, challenges, and future perspectives—invoking a call for collective commitment to catalyze a sustainable scientific revolution.
... These can be small organic compounds such as L-proline or N,N-dimethylpyridin-4-amine [5], or in other cases larger compounds can function as organocatalysts, e.g., quinine [5,6]. In recent years, monosaccharide derivatives have been successfully tried out as organocatalysts [7], and a large group of molecules have also been used and tested as organocatalysts in medicinal chemical research [5]. ...
... function as organocatalysts, e.g., quinine [5,6]. In recent years, monosaccharide derivatives have been successfully tried out as organocatalysts [7], and a large group of molecules have also been used and tested as organocatalysts in medicinal chemical research [5]. ...
Carbohydrate-based macrocycles can be enantioselective catalysts in certain reactions. Previously, it was proven that the carbohydrate moiety could affect the catalytic activity of the monoaza-15-crown-5 type macrocycles derived from sugars. According to our experiments so far, the most effective enantioselective catalysts were the d-glucose- and the d-galactose-based crown ethers. To obtain more information about the effect of the carbohydrate unit, a rare monosaccharide, d-idose was incorporated into the monoaza-15-crown-5 structure. The key intermediates were methyl 4,6-O-benzylidene-α-d-idopyranoside and methyl 4,6-O-benzylidene-β-d-idopyranoside, which were synthesized from d-galactose. The efficiency of the idopyranoside-based crown compounds synthesized was investigated in asymmetric phase transfer reactions. In liquid-liquid biphasic reactions the highest enantioselectivity was 81% ee, while in solid-liquid phase systems the highest asymmetric induction was 67% ee. It was observed that the enantiodiscrimination was strongly dependent on the configuration of the anomeric center, on the side arm of the nitrogen, and on the structure of the substrate.
... Carbohydratebased compounds are actually efficient organocatalysts, but the naturally occurring Fig. 23 Combination of physical (marked in blue) and chemical (highlighted in red) processes that enable the kinetic resolution of rac-glyceraldehyde with enantioenriched dipeptides. Adapted and modified from Yu et al. (2021) unprotected precursors should be significantly modified to accommodate functional groups (like thioureido moieties) capable of establishing multiple non-covalent interactions (Mishra et al. 2016;Wojaczynska et al. 2021). In absence of such features, including more rigid skeleta, they exhibit poor or null stereoselection. ...
By paraphrasing one of Kipling’s most amazing short stories (How the Leopard Got His Spots), this article could be entitled “How Sugars Became Homochiral”. Obviously, we have no answer to this still unsolved mystery, and this perspective simply brings recent models, experiments and hypotheses into the homochiral homogeneity of sugars on earth. We shall revisit the past and current understanding of sugar chirality in the context of prebiotic chemistry, with attention to recent developments and insights. Different scenarios and pathways will be discussed, from the widely known formose-type processes to less familiar ones, often viewed as unorthodox chemical routes. In particular, problems associated with the spontaneous generation of enantiomeric imbalances and the transfer of chirality will be tackled. As carbohydrates are essential components of all cellular systems, astrochemical and terrestrial observations suggest that saccharides originated from environmentally available feedstocks. Such substances would have been capable of sustaining autotrophic and heterotrophic mechanisms integrating nutrients, metabolism and the genome after compartmentalization. Recent findings likewise indicate that sugars’ enantiomeric bias may have emerged by a transfer of chirality mechanisms, rather than by deracemization of sugar backbones, yet providing an evolutionary advantage that fueled the cellular machinery.
Multicomponent reactions are operationally simple and display a significant role in diverse chemical modification by reducing reaction times as well as additional steps involved. In this review, we highlighted the impact of multi‐component reactions in assistance with modular Click chemistry to develop a library of triazole‐appended scaffolds including 1,2,3‐triazole‐fused heterocycles, glycoconjugates, macrocycles as well as in the combinatorial synthesis of differently functionalized triazoles along with mechanistic insights with a diverse range of applications in the field of medicinal chemistry.
Glukofuranoz amin ve galaktopiranoz aminden üre ve tiyoüre temelli yeni organokatalizörlerin (7-10) sentezi ve karakterizasyonu yapılmıştır. Bu bileşikler, farklı diketonlara trans-ß-nitrostiren’e enantiyoseçici Michael katılmasında organokatalizör olarak test edilmiştir. Sıcaklık, çözücü ve katkı maddeleri gibi parametreler ile yapılan optimizasyon sonucunda organokatalizörlerin %99 verim ve %11 enantiyomerik aşırılık ile katalizlediği tespit edilmiştir.
The use of carbon dioxide to obtain urea derivatives of saccharides as organocatalysts or cryptands is part of the assumptions of modern organic synthesis. Sugars as compounds of natural origin with high optical purity are easily available and at the same time cheap as substrates. Their hydrophilicity allows the reactions to be carried out in the water. The combination of the advantages of saccharides with the elimination of carbon dioxide from the environment is the main topic of this publication.
Organocatalysis has emerged as one of the most progressive and prevailing field of organic synthesis to assist green chemistry. Constantly increasing demand of promising scaffolds to develop potent organocatalysts has impelled researchers to utilize the unique traits of carbohydrate moiety in this field. Biological significance of carbohydrates, as well as, their high natural abundance as chiral non‐racemic material, presence of multiple hydroxyl groups, several stereogenic centres, and easily modifiable structure make this moiety an appropriate skeleton to develop organocatalysts to enhance productivity and selectivity of a chemical transformation. 21st Century has witnessed the progress of carbohydrate moiety in development of organocatalysts from obscurity to eminence. This review encapsulates the importance of carbohydrate scaffolds in organocatalysis mainly dealing with the synthesis and applications carbohydrate‐derived organocatalyst in different common organic reactions with their significance and future purspectives.
