ChemInform Abstract: Biomimetic Asymmetric 1,3-Dipolar Cycloaddition: Amino Acid Precursors in Biosynthesis Serve as Latent Azomethine Ylides.

ChemInform ◽  
2013 ◽  
Vol 44 (40) ◽  
pp. no-no
Author(s):  
Chang Guo ◽  
Jin Song ◽  
Liu-Zhu Gong
Keyword(s):  
Amino Acid ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
Amino Acid Precursors

scholarly journals Chiral 1,2-Diaminocyclohexane-α-Amino Acid-Derived Amidphos/Ag(I)-Catalyzed Divergent Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Ylides

Heterocycles ◽  
2022 ◽  
Vol 104 (1) ◽  
pp. 123
Author(s):  
Jie Luo ◽  
Youshi Liu ◽  
Haifei Wang ◽  
Chuliang Gong ◽  
Zhipeng Zhou ◽  
...  
Keyword(s):  
Amino Acid ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition

Diastereoselective 1,3-Dipolar Cycloadditions and Michael Reactions of Azomethine Ylides to (2R)-3-Benzoyl-4-methylidene-2-phenyloxazolidin-5-one and (2S)-3-Benzoyl-2-t-butyl-4-methylideneoxazolidin-5-one

1998 ◽  
Vol 51 (2) ◽  
pp. 137 ◽  
Author(s):  
Stephen G. Pyne ◽  
Javad Safaei-G. ◽  
Karl Schafer ◽  
Abdollah Javidan ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Amino Acid ◽  
Azomethine Ylides ◽  
Dipolar Cycloaddition ◽  
Amino Acid Esters ◽  
Dipolar Cycloadditions ◽  
Michael Reactions ◽  
Michael Adducts ◽  
Practical Synthesis ◽  
The Michael Addition ◽  
Acid Esters

The 1,3-dipolar cycloaddition reactions of (1) and (11) with the azomethine ylides derived from N-benzylidene α-amino acid esters (2) proceed with good to high exo-diastereoselectivity giving the cycloadducts (4) and (12), respectively. The cycloaddition adducts can be converted to highly functionalised prolines (14), (15) and (17) in high enantiomeric purities. The Michael addition adducts of (1) and (11) with the azomethine ylides derived from the N-(disubstituted methylidene) α-amino acid esters (18), (19) and (33) allow for a practical synthesis of all four stereoisomers of 4-benzamidopyroglutamate. The stereochemistry of these cycloaddition and Michael adducts has been extensively determined by single-crystal X-ray structural analysis [compounds (4b), (5b,d), (12b,d), (13e), (15), (20), (21) and (27)]. Lithium-chelated transition state structures have been proposed to rationalize the stereochemical outcomes of these reactions.

scholarly journals Synthesis of pyrrolizidines and indolizidines by multicomponent 1,3-dipolar cycloaddition of azomethine ylides

2019 ◽  
Vol 91 (4) ◽  
pp. 575-596 ◽  
Author(s):  
Carmen Nájera ◽  
José Miguel Sansano
Keyword(s):  
Amino Acid ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Amino Acid Derivatives ◽  
Reaction Conditions ◽  
Dipolar Cycloadditions ◽  
Spiro Derivatives ◽  
Stabilized Azomethine Ylides

Abstract Different multicomponent 1,3-dipolar cycloadditions (1,3-DC) of cyclic α-amino acid derivatives with aldehydes and dipolarophiles have been described as efficient and simple methodologies for the synthesis of the pyrrolidine unit of pyrrolizidines and indolizidines. When free cyclic α-amino acids are used, a thermal promoted decarboxylative process generates in situ the corresponding non-stabilized azomethine ylides, which afforded the corresponding pyrrolizidines and indolizidines with a hydrogen in the bicyclic units. This methodology has been employed to the synthesis of complex systems including spiro derivatives when ketones are used as carbonyl component. In addition, working with cyclic α-amino acid derived esters, the three-component 1,3-DC takes place under milder reaction conditions giving the corresponding pyrrolizidines and indolizidines with an alkoxycarbonyl group in the bridge adjacent carbon to the nitrogen. This methodology can be carried out by a double consecutive or stepwise 1,3-DC to provide pyrrolizidines via the precursor prolinates. The conformation of the azomethine ylide controls the endo/exo diastereoselectivity of the 1,3-DC.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

scholarly journals Arcopilus aureus MaC7A as a New Source of Resveratrol: Assessment of Amino Acid Precursors, Volatiles, and Fungal Enzymes for Boosting Resveratrol Production in Batch Cultures

2021 ◽  
Vol 11 (10) ◽  
pp. 4583
Author(s):  
Nemesio Villa-Ruano ◽  
Luis Ángel Morales-Mora ◽  
Jenaro Leocadio Varela-Caselis ◽  
Antonio Rivera ◽  
María de los Ángeles Valencia de Ita ◽  
...  
Keyword(s):  
Amino Acid ◽  
Filamentous Fungi ◽  
Hydrolytic Enzymes ◽  
Glucanase Activity ◽  
Fungal Enzymes ◽  
Activity Increase ◽  
Batch Cultures ◽  
Low Concentrations ◽  
Chemical Factors ◽  
Amino Acid Precursors

The chemical factors that regulate the synthesis of resveratrol (RV) in filamentous fungi are still unknown. This work reports on the RV production by Arcopilus aureus MaC7A under controlled conditions and the effect of amino acid precursors (PHE and TYR), monoterpenes (limonone, camphor, citral, thymol, menthol), and mixtures of hydrolytic enzymes (Glucanex) as elicitors for boosting fungal RV. Batch cultures with variable concentrations of PHE and TYR (50–500 mg L−1) stimulated RV production from 127.9 ± 4.6 to 221.8 ± 5.2 mg L−1 in basic cultures developed in PDB (pH 7) added with 10 g L−1 peptone at 30 °C. Maximum levels of RV and biomass were maintained during days 6–8 under these conditions, whereas a dramatic RV decrease was observed from days 10–12 without any loss of biomass. Among the tested volatiles, citral (50 mg L−1) enhanced RV production until 187.8 ± 2.2 mg L−1 in basic cultures, but better results were obtained with Glucanex (100 mg L−1; 198.3 ± 7.6 mg L−1 RV). Optimized batch cultures containing TYR (200 mg L−1), citral (50 mg L−1), thymol (50 mg L−1), and Glucanex (100 mg L−1) produced up to 237.6 ± 4.7 mg L−1 of RV. Our results suggest that low concentrations of volatiles and mixtures of isoenzymes with β-1, 3 glucanase activity increase the biosynthesis of fungal RV produced by A. aureus MaC7A in batch cultures.

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