scholarly journals Current applications of kinetic resolution in the asymmetric synthesis of substituted pyrrolidines

2021 ◽  
Author(s):  
Sian Stephanie Berry ◽  
Simon Jones
Keyword(s):  
Asymmetric Synthesis ◽  
Traditional Method ◽  
Kinetic Resolution ◽  
Biologically Active ◽  
Enantiomerically Pure ◽  
Pure Compounds

Chiral substituted pyrrolidines are key elements in various biologically active molecules and are therefore valuable synthetic targets. One traditional method to enantiomerically pure compounds is the application of kinetic resolution....

scholarly journals Altering the Stereoselectivity of Whole-Cell Biotransformations via the Physicochemical Parameters Impacting the Processes

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 781
Author(s):  
Agnieszka Raczyńska ◽  
Joanna Jadczyk ◽  
Małgorzata Brzezińska-Rodak
Keyword(s):  
Culture Conditions ◽  
Biologically Active ◽  
Enantiomerically Pure ◽  
Whole Cells ◽  
Chiral Compounds ◽  
Physicochemical Factors ◽  
Pure Compounds ◽  
Genetic Level ◽  
Prochiral Ketones ◽  
Optically Pure

The enantioselective synthesis of organic compounds is one of the great challenges in organic synthetic chemistry due to its importance for the acquisition of biologically active derivatives, e.g., pharmaceuticals, agrochemicals, and others. This is why biological systems are increasingly applied as tools for chiral compounds synthesis or modification. The use of whole cells of “wild-type” microorganisms is one possible approach, especially as some methods allow improving the conversion degrees and controlling the stereoselectivity of the reaction without the need to introduce changes at the genetic level. Simple manipulation of the culture conditions, the form of a biocatalyst, or the appropriate composition of the biotransformation medium makes it possible to obtain optically pure products in a cheap, safe, and environmentally friendly manner. This review contains selected examples of the influence of physicochemical factors on the stereochemistry of the biocatalytic preparation of enantiomerically pure compounds, which is undertaken through kinetically controlled separation of their racemic mixtures or reduction of prochiral ketones and has an effect on the final enantiomeric purity and enantioselectivity of the reaction.

Overview: Enzyme-catalyzed Enantioselective Biotransformation of Chiral Active Compounds Used in Hypertension Treatment

2020 ◽  
Vol 24 (23) ◽  
pp. 2782-2791
Author(s):  
Joanna Chałupka ◽  
Adam Sikora ◽  
Aleksandra Kozicka ◽  
Michał Piotr Marszałł
Keyword(s):  
Kinetic Resolution ◽  
Enzymatic Reactions ◽  
Reaction Conditions ◽  
Enantiomerically Pure ◽  
Pharmaceutical Ingredients ◽  
Enzymatic Kinetic Resolution ◽  
Treatment Of Hypertension ◽  
Pure Compounds ◽  
Β Blockers ◽  
Asymmetric Carbon

Enzymatic kinetic resolution is one of the methods which allows for the synthesis of enantiomerically pure various active pharmaceutical ingredients. In contrast to chemical routes, enzymatic reactions have characteristics, including mild reaction conditions, a few byproducts, and relatively high activity of the used enzymes. β-adrenolytic drugs are widely used in the treatment of hypertension and cardiovascular disorders. Due to the fact that β- blockers possess an asymmetric carbon atom in their structure, they are presented in two enantiomeric forms. It was reported by many studies that only the (S)-enantiomers of these drugs possess the desired therapeutic effect, whereas the administration of the racemate may cause dangerous side effects, such as bronchoconstriction or diabetes. Nevertheless, β- blockers are still commercially available drugs mainly used in medicine as racemates, whereas there are several methods that are widely used in order to obtain enantiomerically pure compounds.

Recent Advances in Catalytic Nonenzymatic Kinetic Resolution of Tertiary Alcohols

Synthesis ◽  
2021 ◽  
Author(s):  
Bo Ding ◽  
Qilin Xue ◽  
Shihu Jia ◽  
Hong-Gang Cheng ◽  
Qianghui Zhou
Keyword(s):  
Asymmetric Catalysis ◽  
Kinetic Resolution ◽  
Rapid Development ◽  
Short Review ◽  
Biologically Active ◽  
Metal Catalysis ◽  
Tertiary Alcohols ◽  
Chiral Compounds ◽  
Recent Advances ◽  
Pure Compounds

The kinetic resolution (KR) of racemates is one of the most widely used approaches to access enantiomerically pure compounds. Over the past two decades, catalytic nonenzymatic KR has gained popularity in the field of asymmetric synthesis due to the rapid development of chiral catalysts and ligands in asymmetric catalysis. Chiral tertiary alcohols are prevalent in a variety of natural products, pharmaceuticals, and biologically active chiral compounds. The catalytic nonenzymatic KR of racemic tertiary alcohols is a straightforward strategy to access enantioenriched tertiary alcohols. This short review describes recent advances in catalytic nonenzymatic KR of tertiary alcohols, including organocatalysis and metal catalysis.

Catalyst- and Silane- Controlled Enantioselective Hydrofunctionalization of Alkenes by Cobalt-Catalyzed Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Kousuke Ebisawa ◽  
Kana Izumi ◽  
Yuka Ooka ◽  
Hiroaki Kato ◽  
Sayori Kanazawa ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Absolute Configuration ◽  
Kinetic Resolution ◽  
Hydrogen Atom Transfer ◽  
Biologically Active ◽  
Atom Transfer ◽  
High Concentration ◽  
Chain Reaction ◽  
Radical Chain ◽  
Radical Chain Reaction

Catalytic enantioselective synthesis of tetrahydrofurans, which are found in the structures of many biologically active natural products, via a transition-metal catalyzed-hydrogen atom transfer (TM-HAT) and radical-polar crossover (RPC) mechanism is described herein. Hydroalkoxylation of non-conjugated alkenes proceeded efficiently with excellent enantioselectivity (up to 94% ee) using a suitable chiral cobalt catalyst, <i>N</i>-fluoro-2,4,6-collidinium tetrafluoroborate, and diethylsilane. Surprisingly, absolute configuration of the product was highly dependent on the steric hindrance of the silane. Slow addition of the silane, the dioxygen effect in the solvent, thermal dependency, and DFT calculation results supported the unprecedented scenario of two competing selective mechanisms. For the less-hindered diethylsilane, a high concentration of diffused carbon-centered radicals invoked diastereoenrichment of an alkylcobalt(III) intermediate by a radical chain reaction, which eventually determined the absolute configuration of the product. On the other hand, a more hindered silane resulted in less opportunity for radical chain reaction, instead facilitating enantioselective kinetic resolution during the late-stage nucleophilic displacement of the alkylcobalt(IV) intermediate.

Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

2020 ◽  
Vol 24 (8) ◽  
pp. 900-908
Author(s):  
Ram Naresh Yadav ◽  
Amrendra K Singh ◽  
Bimal Banik
Keyword(s):  
Asymmetric Synthesis ◽  
Chiral Auxiliary ◽  
Bioactive Molecules ◽  
One Pot ◽  
Enantiomerically Pure ◽  
Stereoselective Glycosylation ◽  
One Pot Synthesis ◽  
Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

scholarly journals Asymmetric Synthesis of 2‐Arylindolines and 2,2‐Disubstituted Indolines by Kinetic Resolution

2021 ◽  
Author(s):  
Iain Coldham ◽  
Anthony Choi ◽  
Ashraf El-Tunsi ◽  
Yuhang Wang ◽  
Anthony J. H. M. Meijer ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Kinetic Resolution

scholarly journals Evaluation of Basidiomycetes Wild Strains Grown in Agro-Industrial Residues for Their Anti-Tyrosinase and Antioxidant Potential and for the Production of Biocatalysts

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 19
Author(s):  
Anastasia Zerva ◽  
Nikolaos Tsafantakis ◽  
Evangelos Topakas
Keyword(s):  
Biomass Conversion ◽  
White Rot Fungi ◽  
Ligninolytic Enzymes ◽  
Inhibitory Effect ◽  
Biologically Active ◽  
White Rot ◽  
Oxidative Enzymes ◽  
Industrial Residues ◽  
Pure Compounds ◽  
Wild Strains

White-rot basidiomycetes are the only microorganisms with the ability to produce both hydrolytic (cellulases and hemicellulases) and oxidative (ligninolytic) enzymes for degrading cellulose/hemicellulose and lignin. In addition, they produce biologically active natural products with important application in cosmetic formulations, either as pure compounds or as standardized extracts. In the present work, three wild strains of Basidiomycetes fungi (Pleurotus citrinopileatus, Abortiporus biennis and Ganoderma resinaceum) from Greek habitats were grown in agro-industrial residues (oil mill wastewater, and corn cob) and evaluated for their anti-tyrosinase and antioxidant activity and for the production of biotechnologically relevant enzymes. P. citrinopileatus showed the most interesting tyrosinase inhibitory activity, while A. biennis showed the highest DPPH(2,2-diphenyl-1-picryl-hydrazyl) scavenging potential. Corn cobs were the most appropriate carbon source for maximizing the inhibitory effect of fungal biomasses on both activities, while the use of oil mill wastewater selectively increased the anti-tyrosinase potential of P. citrinopileatus culture filtrate. All strains were found to be preferential lignin degraders, similarly to most white-rot fungi. Bioinformatic analyses were performed on the proteome of the strains P. citrinopileatus and A. biennis, focusing on CAZymes with biotechnological relevance, and the results were compared with the enzyme activities of culture supernatants. Overall, all three strains showed strong production of oxidative enzymes for biomass conversion applications.

Sign in / Sign up

Export Citation Format

Share Document