Results 51 to 60 of about 25,799 (236)

Diversity-Oriented Synthesis of Novel Trihalomethyl-Containing Spirochromeno[3,4-a](thia)pyrrolizidines and Spirochromeno-[3,4-a]indolizidines by One-Pot, Three-Component [3+2]-Cyclo­addition Reaction

open access: yesSynOpen, 2021
Regio- and stereoselective methods for the synthesis of 6′-trifluoro(trichloro)methyl substituted spiro[acenaphthylene-1,11′-chromeno[3,4-a](thia)pyrrolizidin]-2-ones and spiro[acenaphthylene-1,12′-chromeno[3,4-a]indolizidin]-2-ones have been developed ...
Igor B. Kutyashev   +6 more
doaj   +1 more source

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

open access: yesBeilstein Journal of Organic Chemistry, 2023
The [3 + 2] cycloadditions of stabilized azomethine ylides (AMYs) derived from amino esters are well-established. However, the reactions of semi-stabilized AMYs generated from decarboxylative condensation of α-amino acids with arylaldehydes are much less
Xiaofeng Zhang, Xiaoming Ma, Wei Zhang
doaj   +1 more source

Graphene Oxide Catalyzed Synthesis of Fused Chromeno Spiro Pyrrolidine Oxindoles via Tandem Decarboxylation and 1,3-Dipolar Cycloaddition

open access: yesFrontiers in Chemistry, 2022
A short and efficient multicomponent sequence for synthesizing fused novel polyheterocyclic chromeno spiro-pyrrolidine oxindoles via 1,3-dipolar cycloaddition reaction mediated by reactive azomethine ylides catalyzed by the Graphene Oxide (GO) is ...
Vipin Singh   +2 more
doaj   +1 more source

An Efficient Synthesis of Novel Dispirooxindole Derivatives via One-Pot Three-Component 1,3-Dipolar Cycloaddition Reactions

open access: yesMolecules, 2012
A series of novel dispirooxindoles have been synthesized through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and an α-amino acid with the dipolarophile 5-benzylidene-1,3 ...
Yucheng Wang   +9 more
doaj   +1 more source

Enantioselective 1,3-Dipolar Cycloaddition Using (Z)-α-Amidonitroalkenes as a Key Step to the Access to Chiral cis-3,4-Diaminopyrrolidines

open access: yesMolecules, 2022
The enantioselective 1,3-dipolar cycloaddition between imino esters and (Z)-nitroalkenes bearing a masked amino group in the β-position was studied using several chiral ligands and silver salts.
Eduardo García-Mingüens   +5 more
doaj   +1 more source

<i>N</i>-Oxide Insertion into LDA Dimeric Aggregates for Azomethine Ylide Formation: Explicit Solvation in Quantum Mechanical Treatment of Polarized Intermediates. [PDF]

open access: hybridJ Org Chem
Neal MJ   +10 more
europepmc   +2 more sources

Enantiomerically Enriched Aziridine‐2‐carboxylates via Copper‐Catalyzed Reductive Kinetic Resolution of 2H‐Azirines

open access: yesAngewandte Chemie, Volume 137, Issue 26, June 24, 2025.
Kinetic resolution by copper hydride catalyzed reduction of 2H‐azirines secured optically enriched N‐H aziridine‐2‐carboxylates with excellent diastereoselectivity (>20:1) and good enantioselectivity (up to 94% ee). DFT calculations and non‐covalent interaction analysis established the reaction pathway and revealed two key non‐covalent interactions ...
Yinuo Zheng   +3 more
wiley   +2 more sources

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

open access: yesiScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen   +5 more
doaj   +1 more source

Stereoselective Synthesis of the Di-Spirooxindole Analogs Based Oxindole and Cyclohexanone Moieties as Potential Anticancer Agents

open access: yesMolecules, 2021
A new series of di-spirooxindole analogs, engrafted with oxindole and cyclohexanone moieties, were synthesized. Initially, azomethine ylides were generated via reaction of the substituted isatins 3a–f (isatin, 3a, 6-chloroisatin, 3b, 5-fluoroisatin, 3c ...
Abdullah Mohammed Al-Majid   +7 more
doaj   +1 more source

The regioselective synthesis of spirooxindolo pyrrolidines and pyrrolizidines via three-component reactions of acrylamides and aroylacrylic acids with isatins and α-amino acids

open access: yesBeilstein Journal of Organic Chemistry, 2014
The regioselective three-component condensation of azomethine ylides derived from isatins and α-amino acids with acrylamides or aroylacrylic acids as dipolarophiles has been realized through a one-pot 1,3-dipolar cycloaddition protocol.
Tatyana L. Pavlovskaya   +6 more
doaj   +1 more source

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