scholarly journals Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

2020 ◽  
Vol 16 ◽  
pp. 2671-2678
Author(s):  
Ziyi Li ◽  
Li Wang ◽  
Yunqi Huang ◽  
Haibo Mei ◽  
Hiroyuki Konno ◽  
...  
Keyword(s):  
Column Chromatography ◽  
Addition Reactions ◽  
Mannich Reactions ◽  
Enantiomerically Pure ◽  
Pure Compounds

In the present work, arylethynes were studied as new C-nucleophiles in the asymmetric Mannich addition reactions with (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimine. The reactions were conducted under operationally convenient conditions affording the corresponding Mannich adducts with up to 87% yield and 70:30 diastereoselectivity. The isomeric products can be separated using regular column chromatography to afford diastereomerically pure compounds. The purified Mannich addition products were deprotected to give the target enantiomerically pure trifluoromethylpropargylamines. A mechanistic rationale for the observed stereochemical outcome is discussed.

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.

ChemInform Abstract: Hydrolases in Organic Synthesis: Preparation of Enantiomerically Pure Compounds

ChemInform ◽  
2010 ◽  
Vol 23 (43) ◽  
pp. no-no
Author(s):  
U. ADER ◽  
P. ANDERSCH ◽  
M. BERGER ◽  
U. GOERGENS ◽  
R. SEEMAYER ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Enantiomerically Pure ◽  
Pure Compounds

scholarly journals Bioreduction of α,β-unsaturated carbonyl compounds by Lasiodiplodia pseudotheobromae, endophytic fungus from Morinda citrifolia (RUBIACEAE)

2020 ◽  
Vol 9 (10) ◽  
pp. e9739109419
Author(s):  
Mark Carvalho da Silva ◽  
Maricelia Lopes dos Anjos ◽  
Luana Cardoso de Oliveira ◽  
Patrícia Santana Barbosa Marinho ◽  
Alessandra Keiko Nakasone ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbonyl Compounds ◽  
High Performance ◽  
Room Temperature ◽  
Morinda Citrifolia ◽  
Enantiomerically Pure ◽  
Food Industries ◽  
Pure Compounds ◽  
Layer Chromatography ◽  
Orbital Shaker

Biotransformations are reactions carried out by microorganisms that lead to changes in the structures of organic compounds, among the biotransformations there are bioreductions. Bioreductions are of great interest to the pharmaceutical and food industries, as they almost always lead to the formation of enantiomerically pure compounds. Thus, this work aimed to verify the ability of the fungus Lasiodiplodia pseudotheobromae in bioreduce α,β-unsaturated carbonyl compounds. Compounds (3E)-4-(2-methoxy-phenyl)-but-3-en-2-one (1), (1E, 4E)-1,5-diphenyl-pent-1,4-dien-3-one (2) and (1E, 4E)-1,5-bis-(2-methoxy-phenyl)-penta-1,4-dien-3-one (3) were used as substrates. The reactions were carried out on an orbital shaker for 8 days at room temperature. The products formed were characterized by analytical thin layer chromatography (ATLC), high performance liquid chromatography (HPLC) and hydrogen nuclear magnetic resonance (1H NMR). For all products formed was observed reduction in double bonds C=C and C=O leading to the formation of the respective alcohols. This is the first report of biotransformation reactions using the fungus Lasiodiplodia pseudotheobromae.

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.

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