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.

ChemInform Abstract: Oligopyrrole Synthesis by 1,3-Dipolar Cycloaddition of Azomethine Ylides with Bissulfonyl Ethylenes.

ChemInform ◽  
2008 ◽  
Vol 39 (15) ◽  
Author(s):  
Ana Lopez-Perez ◽  
Rocio Robles-Machin ◽  
Javier Adrio ◽  
Juan Carlos Carretero
Keyword(s):  
Azomethine Ylides ◽  
Dipolar Cycloaddition
Sign in / Sign up

Export Citation Format

Share Document