Results 41 to 50 of about 4,038 (213)

A simple two-step synthesis of 2-(alkylamino)-1-arylethanols, including racemic adrenaline, from aromatic aldehydes via 5-aryloxazolidines [PDF]

open access: yes, 2013
Benzaldehydes react smoothly with nonstabilized azomethine ylides, generated in situ from sarcosine/formaldehyde or N-(methoxymethyl)-N- (trimethylsilylmethyl)benzylamine, to give 5-aryloxazolidines as intermediates.
Moshkin, V. S., Sosnovskikh, V. Y.
core   +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

Enantioselective Synthesis of exo-4-Nitroprolinates from Nitro­alkenes and Azomethine Ylides Catalyzed by Chiral Phosphor­amidite·Silver(I) or Copper(II) Complexes [PDF]

open access: yes, 2015
Chiral complexes formed by privileged phosphoramidites derived from chiral binol and optically pure Davies’ amines, and copper(II) triflate, silver(I) triflate or silver(I) benzoate are excellent catalysts for the general 1,3-dipolar cycloaddition ...
Castelló Moncayo, Luis Miguel   +5 more
core   +2 more sources

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

Binap-silver-catalyzed enantioselective multicomponent 1,3-dipolar cycloaddition of azomethines ylides derived from ethyl glyoxylate [PDF]

open access: yes, 2015
The enantioselective binap–silver catalyzed multicomponent 1,3-dipolar cycloaddition using ethyl glyoxylate, phenylalanine ethyl ester, and maleimides is described. The employment of basic silver carbonate allows the reaction to take place in the absence
Mancebo Aracil, Juan   +2 more
core   +2 more sources

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

Aziridination of a Single Carbon Atom in Alkenes via Energy Transfer Catalysis

open access: yesAngewandte Chemie International Edition, EarlyView.
Contrary to traditional alkene aziridination via (formal) nitrene transfer, we herein report a strategy that achieves intermolecular aziridination of a single alkene carbon atom and installs an additional group at the other. Enabled by metal‐free energy transfer (EnT) catalysis, alkenyl boronates and silanes are transformed into reactive intermediates ...
Fritz Paulus   +7 more
wiley   +1 more source

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