Results 31 to 40 of about 2,875 (189)

A General Pyrrolidine Synthesis via Iridium-Catalyzed Reductive Azomethine Ylide Generation from Tertiary Amides & Lactams [PDF]

open access: gold, 2021
Ken Yamazaki   +6 more
openalex   +3 more sources

A Facile Synthesis of Functionalized Dispirooxindole Derivatives via a Three-Component 1,3-Dipolar Cycloaddition Reaction

open access: yesMolecules, 2013
An efficient synthesis of novel dispirooxindoles has been achieved 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 ...
Liang Ouyang   +5 more
doaj   +1 more source

Computational Study of Ignored Pericyclic Reactions: Rearrangements of 1,2‐Bis(Diazo)Alkanes to 1,2,3,4‐Tetrazines and Subsequent Fragmentations

open access: yesAngewandte Chemie, Volume 137, Issue 45, November 3, 2025.
DFT calculations of the 8π‐electrocyclization of 1,2‐bis(diazo)alkanes and of other bis‐1,3‐dipoles reveal that this process can establish a so far ignored route to heterocycles such as 1,2,3,4‐tetrazines. Alternative reaction channels via carbenes or nitrenes leading to fragmentation products are discussed.
Hans‐Ulrich Reissig   +1 more
wiley   +2 more sources

Facile, Regio- and Diastereoselective Synthesis of Spiro-Pyrrolidine and Pyrrolizine Derivatives and Evaluation of Their Antiproliferative Activities

open access: yesMolecules, 2014
A number of novel spiro-pyrrolidines/pyrrolizines derivatives were synthesized through [3+2]-cycloaddition of azomethine ylides with 3,5-bis[(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones 2a–n.
Abdulrahman I. Almansour   +11 more
doaj   +1 more source

The Photochemistry of N-Iminopyridinium Ylides in Retrospect. From a Simple Concept to Some Applications

open access: yesCHIMIA, 1991
Azomethine-imines are well known to undergo ground-state 1,3-dipolar cycloaddition reactions with olefins or acetylenes, leading thereby to five-membered heterocyclic systems. When excited by UV light, some of these 1,3-dipolar azomethine-imines
Jacques Streith
doaj   +2 more sources

Triethylamine-Promoted Oxidative Cyclodimerization of 2H-Azirine-2-carboxylates to Pyrimidine-4,6-dicarboxylates: Experimental and DFT Study

open access: yesMolecules, 2023
An unprecedented oxidative cyclodimerization reaction of 2H-azirine-2-carboxylates to pyrimidine-4,6-dicarboxylates under heating with triethylamine in air is described. In this reaction, one azirine molecule undergoes formal cleavage across the C-C bond
Timofei N. Zakharov   +4 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

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

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

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

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