scholarly journals Synthesis of polysubstituted spiropyrrolidines using 2-acetylfuran, 2-acetylthiophene, and 2-acetylpyrrole

Author(s):  
Svetlana V. Borisova ◽  
◽  
Vitaly V. Sorokin ◽  

A series of novel spirooxindoles have been synthesized through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and sarcosine with the dipolarophile 3-phenyl-1-(heteroaryl -2-yl)prop-2-en-1- one, synthesized by the Knoevenagel reaction using 2-acetylfuran, 2-acetylpyrrole, 2-acetylthiophene and substituted benzaldehydes. These compounds are used for the first time as dipolarophiles. This method has the advantages of mild reaction conditions, high atom economy, excellent yields, and high regio- and stereo-selectivity. The reaction was carried out by mixing equimolar amounts of enone and isatin, as well as a slight excess of sarcosine in isopropyl alcohol when heated to 60–70°C. Among the enones with various heterocyclic substituents, it is most convenient to use compounds containing a pyrrole fragment as dipolarophiles, since the products are obtained in a short amount of time in good yields. The use of enones obtained from 2-acetylthiophene leads to an increase in the reaction time, and from 2-acetylfuran - to a significant resinification of the reaction mixture. The structures of the compounds obtained were proved using a combination of 1H, 13C NMR spectroscopy data, as well as two-dimensional NMR experiments of heteronuclear correlation, HSQC and HMBC. Based on the data obtained, a mechanism for the formation of products has been proposed.

2019 ◽  
Vol 91 (4) ◽  
pp. 575-596 ◽  
Author(s):  
Carmen Nájera ◽  
José Miguel Sansano

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.


2020 ◽  
Author(s):  
Agathe C. A. D’Hollander ◽  
Eugénie Romero ◽  
Kamsana Vijayakumar ◽  
Camille le Houérou ◽  
Pascal Retailleau ◽  
...  

Under basic conditions and heat, ynamides can serve as precursor to ketenimines, whose synthetic potential is often hampered by their difficulty of acces. Herein, we report that they can undergo a [3+2] cycloaddition with 2-azaallyl anions, obtained from benzylimines under the same reaction conditions. This reaction between two highly reactive intermediates, both generated in situ from bench stable starting materials, gives access to various nitrogen-rich heterocycles. The reaction usually proceeds with excellent diastereoselectivity, in favor of the cis adduct. Deuteration experiments and DFT calculation helped rationalize the regio and stereo-selectivity of the process as well as the formation of side-products.<br>


Synthesis ◽  
2020 ◽  
Vol 52 (09) ◽  
pp. 1387-1397
Author(s):  
Mingshu Wu ◽  
Dulin Kong ◽  
Tiao Huang ◽  
Li Liu ◽  
Qinghe Wang

An efficient stereoselective assembly strategy for the construction of pyrrolidin-2,3′-oxindole cis-fused phosphadihydrocoumarins was established. The process involves the condensation of O-vinylphosphonylated salicylaldehydes and 3-amino oxindoles followed by intermolecular cycloaddition with high diastereoselectivity and atom economy.


Synthesis ◽  
2018 ◽  
Vol 51 (03) ◽  
pp. 713-729 ◽  
Author(s):  
Vitali Boitsov ◽  
Alexander Stepakov ◽  
Alexander Filatov ◽  
Nickolay Knyazev ◽  
Stanislav Shmakov ◽  
...  

A simple, efficient and atom-economic method has been developed for the synthesis of complex alkaloid-like compounds with spiro-fused indolo[2,1-b]quinazoline and cyclopropa[a]pyrrolizine or 3-azabicyclo[3.1.0]hexane moieties. We have found that one-pot, three-component 1,3-dipolar cycloaddition reactions allow the desired products to be obtained from various cyclopropene derivatives with tryptanthrin-derived azomethine ylides generated in situ, in good to high yields and excellent diastereoselectivity. The possibility of ylide generation was exemplified by using α-amino acids (l-proline, l-4-thiazolidincarboxylic acid) and simplest peptides (dipeptide Gly-Gly, tripeptide Gly-Gly-Gly). Quantum chemical investigations indicate that the reaction proceeds through the S-shaped azomethine ylide, the interaction of which with cyclopropenes proceeds via a less sterically hindered endo-transition state. The antitumor activity of some of spiro-tryptanthrin derivatives against erythroleukemia (K562), cervical carcinoma (HeLa) and colon carcinoma (CT26) cell lines was evaluated in vitro by MTS-assay.


1997 ◽  
Vol 52 (11) ◽  
pp. 1393-1400 ◽  
Author(s):  
Zahida Maqboor ◽  
Mashooda Hasan ◽  
Kevin T. Potts ◽  
Abdul Malik ◽  
Tanveer Ahmad Nizami ◽  
...  

Abstract 1,3-Dipolar cycloaddition of dipolarophiles (1) and (2) with endocyclic heterocyclic azomethine ylides (4), (14) and (24), prepared in situ, leads to the protected β-and α-C-nucleo-sides (7), (8), (17), (18), (27) and (28), respectively. These, on subsequent hydrolysis, provide the corresponding C-nucleosides. The structures of all the synthesized com pounds are con­ firmed through analytical and spectral data. The assignment of configuration at C -1′ position of the C-nucleosides could be done by a comparative study of the properties of the corre­sponding α and β anomers with a reasonable degree of certainity.


RSC Advances ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12262-12271 ◽  
Author(s):  
Chitrala Teja ◽  
Spoorthy N. Babu ◽  
Ayesha Noor ◽  
J. Arul Daniel ◽  
S. Asha Devi ◽  
...  

A series of spiro-[indoline-3,3′-pyrrolizin/pyrrolidin]-2-ones were synthesized from Cu–TEMPO catalyzed dehydrogenation followed by 1,3-dipolar cycloaddition of azomethine ylides via decarboxylative condensation, resulting in high regioselectivities and yields.


Synthesis ◽  
2020 ◽  
Author(s):  
Zhenjie Gan ◽  
Er-Qing Li ◽  
Ke Li ◽  
Hui Zhang

AbstractA highly efficient copper/GanPhos-catalyzed 1,3-dipolar cyclo­addition­ of azomethine ylides is reported. This viable transformation provides a series of optically active spiro[dihydronaphthalene-2,3′-pyrrolidine]s, bearing one spiro quaternary and three tertiary stereogenic centers, in good yields and with high ee values. This protocol features high diastereo- and enantioselectivity, broad substrate scope and mild reaction conditions.


2020 ◽  
Vol 16 ◽  
pp. 2679-2686
Author(s):  
Alexander P Molchanov ◽  
Mariia M Efremova ◽  
Mariya A Kryukova ◽  
Mikhail A Kuznetsov

The first example of the cycloaddition of in situ-generated azomethine imine under microwave conditions is described. The reaction of 6-aryl-1,5-diazabicyclo[3.1.0]hexanes with 1,3-diphenylprop-2-en-1-ones proceeds regio- and stereoselectively giving mostly good yields of the corresponding perhydropyrazolopyrazoles. The products of the reaction undergo cycloreversion under the reaction conditions.


Author(s):  
Manickam Bakthadoss ◽  
Mohammad Mushaf ◽  
Vishal Agarwal ◽  
Tadiparthi Thirupathi Reddy ◽  
Duddu Savaraiah Sharada

An efficient protocol for the synthesis of tricyclic pyrolidinochromenes has been developed via an intramolecular 1,3-dipolar cycloaddition of azomethine ylides generated in situ from 1,3- dienyl ester tethered O-hydroxyarylaldehyde and...


Author(s):  
Baomin Wang ◽  
Shah Nawaz ◽  
Shiqiang Wei ◽  
Yue Huang ◽  
Wenyao Wang ◽  
...  

In this work, we report a novel one-pot [3+2] cycloaddition of 4-aminopyrazolones, indolenines, and aldehydes. The reaction utilized the in-situ generated azomethine ylides as 1,3-dipoles and 2-alkenylindolenines as dipolarophiles affording...


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