Results 61 to 70 of about 5,623 (241)

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

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

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

Highly diastereoselective 1,3-dipolar cycloaddition of nonstabilized azomethine ylides to 3-nitro-2-trihalomethyl-2H-chromenes: Synthesis of 1-benzopyrano[3,4-c]pyrrolidines [PDF]

, 2013
Reactions of 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes, including 2-unsubstituted derivatives, with N-alkyl-α-amino acids (sarcosine, proline) and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines in good ...
Barkov, A. Y., Kodess, M. I., Korotaev, V. Y., Matochkina, E. G., Moshkin, V. S., Sosnovskikh, V. Y.   +5 more
core   +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

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

Frontiers 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, Shanta Raj Lakshmi, L. Raju Chowhan   +2 more
doaj   +1 more source

New Chemistry of Imidazolinium ylides [PDF]

, 2001
Previous work in this group has shown 4,5-dihydroimidazolium ylides, formed by N- alkylation of 4,5-dihydroimidazoles, to undergo 1,3-dipolar cycloadditions with a range of dipolarophiles in a highly regio- and stereoselective fashion.
Lory, Pedro M. J.
core   +1 more source

Domino 1,3-Dipolar Cycloadditions of N-Alkyl-α-Amino Esters with Paraformaldehyde: A Direct Access to α-Hydroxymethyl α-Amino Acids [PDF]

, 2014
N-Alkyl-α-amino esters undergo a domino reaction, based on the iminium cation generation, with paraformaldehyde, followed by a 1,3-dipolar cycloaddition of the stabilized azometh­ine ylide with another equivalent of formaldehyde.
Castelló Moncayo, Luis Miguel, Nájera, Carmen, Sansano, Jose M.   +2 more
core   +2 more sources

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

Molecules, 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, Juxian Wang, Hongtao Liu, Huiyuan Wang, Wei Lin, Lexing Xu, Zhibin Huang, Gang Chen, Qian Zhao, Daqing Shi   +9 more
doaj   +1 more source

Catalysis in Chemical Modification of Proteins

ChemCatChem, EarlyView.
Catalytic principles of synthetic organic chemistry have been increasingly applied to chemical modification of proteins during the recent years. This review article describes how seven types of catalytic systems —electrocatalysis, photocatalysis, metal catalysis, acid catalysis, organocatalysis, supramolecular catalysis, and heterogeneous catalysis ...
Seiya Ishizawa, Koki Fujimura, Kounosuke Oisaki, Shinichi Sato, Jun Ohata   +4 more
wiley   +1 more source