Results 21 to 30 of about 852 (167)

Site-Selective Modification of a Porpholactone—Selective Synthesis of 12,13- and 17,18-Dihydroporpholactones

Molecules, 2020
The reaction of meso-tetrakis(pentafluorophenyl)porpholactone with azomethine ylides and nitrones affords pyrrolidine-fused and isoxazolidine-fused dihydroporpholactones that display, respectively, isobacteriochlorin- and chlorin-type UV–Vis spectra ...
Ana F. R. Cerqueira, Gustautas Snarskis, Jonas Zurauskas, Samuel Guieu, Filipe A. Almeida Paz, Augusto C. Tomé   +5 more
doaj   +1 more source

Synthesis of Spirocyclic Amines by 1,3-Dipolar Cycloaddition of Azomethine Ylides and Azomethine Imines [PDF]

Synthesis, 2020
Simple ketone starting materials with a halide leaving group and an alkene were prepared in one step and heated with glycine or glycine esters to promote a tandem imine formation, cyclization, and dipolar cycloaddition cascade. The chemistry was also feasible with acetylhydrazide.
Choi, A., Castle, J., Saruengkhanphasit, R., Coldham, I.   +3 more
openaire   +2 more sources

Highly Efficient Construction of Sugar-Fused Spirochromanono Pyrrolidines/Pyrrolizidines/Thiolizidines via 1,3-Dipolar Cycloaddition of Azomethine Ylides

SynOpen, 2017
A variety of sugar-fused chromanono pyrrolidines/pyrrolizidines/thiolizidines have been synthesized by intermolecular 1,3-dipolar cycloaddition reaction of azomethine ylides (generated from glucose aldehyde and different secondary amino acids) with ...
Sirisha Nallamala, Srikumar Mannem, Raghunathan Raghavachary   +2 more
doaj   +1 more source

Enantiomerically Enriched 1,2-P,N-Bidentate Ferrocenyl Ligands for 1,3-Dipolar Cycloaddition and Transfer Hydrogenation Reactions

Molecules, 2018
Novel complexes of 1,2-P,N-bidentate ferrocenyl ligands with AgOAc or with [RuCl2(PPh3)3] as catalysts have been studied in asymmetric synthesis. The catalytic activity of these systems have been studied in [3+2]-cycloaddition of azomethine ylides with ...
Irina A. Utepova, Polina O. Serebrennikova, Marina S. Streltsova, Alexandra A. Musikhina, Tatiana G. Fedorchenko, Oleg N. Chupakhin, Andrey P. Antonchick   +6 more
doaj   +1 more source

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

Molecules, 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, Rongsheng Tong, Jianyou Shi, Zhixiang Yuan, Guang Ouyang, Jun He   +5 more
doaj   +1 more source

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

Molecules, 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, Raju Suresh Kumar, Farzana Beevi, Amir Nasrolahi Shirazi, Hasnah Osman, Rusli Ismail, Tan Soo Choon, Brian Sullivan, Kellen McCaffrey, Alaa Nahhas, Keykavous Parang, Mohamed Ashraf Ali   +11 more
doaj   +1 more source

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

CHIMIA, 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

Molecules, 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, Pavel A. Sakharov, Mikhail S. Novikov, Alexander F. Khlebnikov, Nikolai V. Rostovskii   +4 more
doaj   +1 more source

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

Beilstein 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

SynOpen, 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, Maxim S. Sannikov, Ivan A. Kochnev, Alexey Y. Barkov, Nikolay S. Zimnitskiy, Vladislav Y. Korotaev, Vyacheslav Y. Sosnovskikh   +6 more
doaj   +1 more source